Friday, September 28, 2012

Scientists Produce Hydrogen for Fuel Cells Using an Inexpensive Catalyst Under Real-World Conditions

Scientists at the University of Cambridge have produced hydrogen, H2, a renewable energy source, from water using an inexpensive catalyst under industrially relevant conditions (using pH neutral water, surrounded by atmospheric oxygen, O2, and at room temperature).

Lead author of the research, Dr Erwin Reisner, an EPSRC research fellow and head of the Christian Doppler Laboratory at the University of Cambridge, said: "A H2 evolution catalyst which is active under elevated O2 levels is crucial if we are to develop an industrial water splitting process -- a chemical reaction that separates the two elements which make up water. A real-world device will be exposed to atmospheric O2 and also produce O2 in situ as a result of water splitting."

Although H2 cannot be used as a 'direct' substitute for gasoline or ethanol, it can be used as a fuel in combination with fuel cells, which are already available in cars and buses. H2 is currently produced from fossil fuels and it produces the greenhouse gas CO2 as a by-product; it is therefore neither renewable nor clean. A green process such as sunlight-driven water splitting is therefore required to produce 'green and sustainable H2'.

One of the many problems that scientists face is finding an efficient and inexpensive catalyst that can function under real-world conditions: in water, under air and at room temperature. Currently, highly efficient catalysts such as the noble metal platinum are too expensive and cheaper alternatives are typically inefficient. Very little progress was made so far with homogeneous catalyst systems that work in water and atmospheric O2.

However, Cambridge researchers found that a simple catalyst containing cobalt, a relatively inexpensive and abundant metal, operates as an active catalyst in pH neutral water and under atmospheric O2.

Dr Reisner said: "Until now, no inexpensive molecular catalyst was known to evolve H2 efficiently in water and under aerobic conditions. However, such conditions are essential for use in developing green hydrogen as a future energy source under industrially relevant conditions.

"Our research has shown that inexpensive materials such as cobalt are suitable to fulfill this challenging requirement. Of course, many hurdles such as the rather poor stability of the catalyst remain to be addressed, but our finding provides a first step to produce 'green hydrogen' under relevant conditions."

The results show that the catalyst works under air and the researchers are now working on a solar water splitting device, where a fuel H2 and the by-product O2 are produced simultaneously.

Fezile Lakadamyali and Masaru Kato, co-authors of the study, add: "We are excited about our results and we are optimistic that we will successfully assemble a sunlight-driven water splitting system soon."

[Source]

Tuesday, August 21, 2012

Self-Charging Power Cell Converts and Stores Energy

Researchers have developed a self-charging power cell that directly converts mechanical energy to chemical energy, storing the power until it is released as electrical current. By eliminating the need to convert mechanical energy to electrical energy for charging a battery, the new hybrid generator-storage cell utilizes mechanical energy more efficiently than systems using separate generators and batteries.

At the heart of the self-charging power cell is a piezoelectric membrane that drives lithium ions from one side of the cell to the other when the membrane is deformed by mechanical stress. The lithium ions driven through the polarized membrane by the piezoelectric potential are directly stored as chemical energy using an electrochemical process.

By harnessing a compressive force, such as a shoe heel hitting the pavement from a person walking, the power cell generates enough current to power a small calculator. A hybrid power cell the size of a conventional coin battery can power small electronic devices -- and could have military applications for soldiers who might one day recharge battery-powered equipment as they walked.

"People are accustomed to considering electrical generation and storage as two separate operations done in two separate units," said Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "We have put them together in a single hybrid unit to create a self-charging power cell, demonstrating a new technique for charge conversion and storage in one integrated unit."

The research was reported Aug. 9, 2012 in the journal Nano Letters. The research was supported by the Defense Advanced Research Projects Agency (DARPA), the U.S. Air Force, the U.S. Department of Energy, the National Science Foundation, and the Knowledge Innovation Program of the Chinese Academy of Sciences.

The power cell consists of a cathode made from lithium-cobalt oxide (LiCoO2) and an anode consisting of titanium dioxide (TiO2) nanotubes grown atop a titanium film. The two electrodes are separated by a membrane made from poly(vinylidene fluoride) (PVDF) film, which generates a piezoelectric charge when placed under strain. When the power cell is mechanically compressed, the PVDF film generates a piezoelectric potential that serves as a charge pump to drive the lithium ions from the cathode side to the anode side. The energy is then stored in the anode as lithium-titanium oxide.

Charging occurs in cycles with the compression of the power cell creating a piezopotential that drives the migration of lithium ions until a point at which the chemical equilibrium of the two electrodes are re-established and the distribution of lithium ions can balance the piezoelectric fields in the PVDF film. When the force applied to the power cell is released, the piezoelectric field in the PVDF disappears, and the lithium ions are kept at the anode through a chemical process.

The charging cycle is completed through an electrochemical process that oxidizes a small amount of lithium-cobalt oxide at the cathode to Li1-xCoO2 and reduces a small amount of titanium dioxide to LixTiO2 at the anode. Compressing the power cell again repeats the cycle.

When an electrical load is connected between the anode and cathode, electrons flow to the load, and the lithium ions within the cell flow back from the anode side to the cathode side.

Using a mechanical compressive force with a frequency of 2.3 Hertz, the researchers increased the voltage in the power cell from 327 to 395 millivolts in just four minutes. The device was then discharged back to its original voltage with a current of one milliamp for about two minutes. The researchers estimated the stored electric capacity of the power cell to be approximately 0.036 milliamp-hours.

So far, Wang and his research team -- which included Xinyu Xue, Sihong Wang, Wenxi Guo and Yan Zhang -- have built and tested more than 500 of the power cells. Wang estimates that the generator-storage cell will be as much as five times more efficient at converting mechanical energy to chemical energy for as a two-cell generator-storage system.

Much of the mechanical energy applied to the cells is now consumed in deforming the stainless steel case the researchers are using to house their power cell. Wang believes the power storage could be boosted by using an improved case.

"When we improve the packaging materials, we anticipate improving the overall efficiency," he said. "The amount of energy actually going into the cell is relatively small at this stage because so much of it is consumed by the shell."

Beyond the efficiencies that come from directly converting mechanical energy to chemical energy, the power cell could also reduce weight and space required by separate generators and batteries. The mechanical energy could come from walking, the tires of a vehicle hitting the pavement, or by harnessing ocean waves or mechanical vibrations.

"One day we could have a power package ready to use that takes advantage of this hybrid approach," Wang said. "Almost anything that involves mechanical action could provide the strain needed for charging. People walking could be generating electricity as they move."

[Source]

Monday, August 6, 2012

Scientists Use Microbes to Make 'Clean' Methane

Microbes that convert electricity into methane gas could become an important source of renewable energy, according to scientists from Stanford and Pennsylvania State universities.

Researchers at both campuses are raising colonies of microorganisms, called methanogens, which have the remarkable ability to turn electrical energy into pure methane -- the key ingredient in natural gas. The scientists' goal is to create large microbial factories that will transform clean electricity from solar, wind or nuclear power into renewable methane fuel and other valuable chemical compounds for industry.

"Most of today's methane is derived from natural gas, a fossil fuel," said Alfred Spormann, a professor of chemical engineering and of civil and environmental engineering at Stanford. "And many important organic molecules used in industry are made from petroleum. Our microbial approach would eliminate the need for using these fossil resources."

While methane itself is a formidable greenhouse gas, 20 times more potent than CO2, the microbial methane would be safely captured and stored, thus minimizing leakage into the atmosphere, Spormann said.

"The whole microbial process is carbon neutral," he explained. "All of the CO2 released during combustion is derived from the atmosphere, and all of the electrical energy comes from renewables or nuclear power, which are also CO2-free."

Methane-producing microbes, he added, could help solve one of the biggest challenges for large-scale renewable energy: What to do with surplus electricity generated by photovoltaic power stations and wind farms.

"Right now there is no good way to store electricity," Spormann said. "However, we know that some methanogens can produce methane directly from an electrical current. In other words, they metabolize electrical energy into chemical energy in the form of methane, which can be stored. Understanding how this metabolic process works is the focus of our research. If we can engineer methanogens to produce methane at scale, it will be a game changer."

'Green' methane

Burning natural gas accelerates global warming by releasing carbon dioxide that's been trapped underground for millennia. The Stanford and Penn State team is taking a "greener" approach to methane production. Instead of drilling rigs and pumps, the scientists envision large bioreactors filled with methanogens -- single-cell organisms that resemble bacteria but belong to a genetically distinct group of microbes called archaea.

By human standards, a methanogen's lifestyle is extreme. It cannot grow in the presence of oxygen. Instead, it regularly dines on atmospheric carbon dioxideand electrons borrowed from hydrogen gas. The byproduct of this microbial meal is pure methane, which methanogens excrete into the atmosphere.

The researchers plan to use this methane to fuel airplanes, ships and vehicles. In the ideal scenario, cultures of methanogens would be fed a constant supply of electrons generated from emissions-free power sources, such as solar cells, wind turbines and nuclear reactors. The microbes would use these clean electrons to metabolize carbon dioxide into methane, which can then be stockpiled and distributed via existing natural gas facilities and pipelines when needed.

When the microbial methane is burnt as fuel, carbon dioxide would be recycled back into the atmosphere where it originated from -- unlike conventional natural gas combustion, which contributes to global warming.

"Microbial methane is much more ecofriendly than ethanol and other biofuels," Spormann said. "Corn ethanol, for example, requires acres of cropland, as well as fertilizers, pesticides, irrigation and fermentation. Methanogens are much more efficient, because they metabolize methane in just a few quick steps."

Microbial communities

For this new technology to become commercially viable, a number of fundamental challenges must be addressed.

"While conceptually simple, there are significant hurdles to overcome before electricity-to-methane technology can be deployed at a large scale," said Bruce Logan, a professor of civil and environmental engineering at Penn State. "That's because the underlying science of how these organisms convert electrons into chemical energy is poorly understood."

In 2009, Logan's lab was the first to demonstrate that a methanogen strain known as Methanobacterium palustre could convert an electrical current directly into methane. For the experiment, Logan and his Penn State colleagues built a reverse battery with positive and negative electrodes placed in a beaker of nutrient-enriched water.

The researchers spread a biofilm mixture of M. palustre and other microbial species onto the cathode. When an electrical current was applied, the M. palustre began churning out methane gas.

"The microbes were about 80 percent efficient in converting electricity to methane," Logan said.

The rate of methane production remained high as long as the mixed microbial community was intact. But when a previously isolated strain of pure M. palustre was placed on the cathode alone, the rate plummeted, suggesting that methanogens separated from other microbial species are less efficient than those living in a natural community.

"Microbial communities are complex," Spormann added. "For example, oxygen-consuming bacteria can help stabilize the community by preventing the build-up of oxygen gas, which methanogens cannot tolerate. Other microbes compete with methanogens for electrons. We want to identify the composition of different communities and see how they evolve together over time."

Microbial zoo

To accomplish that goal, Spormann has been feeding electricity to laboratory cultures consisting of mixed strains of archaea and bacteria. This microbial zoo includes bacterial species that compete with methanogensfor carbon dioxide, which the bacteria use to make acetate -- an important ingredient in vinegar, textiles and a variety of industrial chemicals.

"There might be organisms that are perfect for making acetate or methane but haven't been identified yet," Spormann said. "We need to tap into the unknown, novel organisms that are out there."

At Penn State, Logan's lab is designing and testing advanced cathode technologies that will encourage the growth of methanogens and maximize methane production. The Penn State team is also studying new materials for electrodes, including a carbon-mesh fabric that could eliminate the need for platinum and other precious metal catalysts.

"Many of these materials have only been studied in bacterial systems but not in communities with methanogens or other archaea," Logan said. "Our ultimate goal is to create a cost-effective system that reliably and robustly produces methane from clean electrical energy. It's high-risk, high-reward research, but new approaches are needed for energy storage and for making useful organic molecules without fossil fuels."

The Stanford-Penn State research effort is funded by a three-year grant from the Global Climate and Energy Project at Stanford.

[Source]

Wednesday, July 25, 2012

Clothing the Body Electric: Cotton T-Shirt Fabric Can Store Electricity, Maybe Keep Your Cell Phone Charged

Over the years, the telephone has gone mobile, from the house to the car to the pocket. The University of South Carolina's Xiaodong Li envisions even further integration of the cell phone -- and just about every electronic gadget, for that matter -- into our lives.
He sees a future where electronics are part of our wardrobe.

"We wear fabric every day," said Li, a professor of mechanical engineering at USC. "One day our cotton T-shirts could have more functions; for example, a flexible energy storage device that could charge your cell phone or your iPad."

Li is helping make the vision a reality. He and post-doctoral associate Lihong Bao have just reported in the journal Advanced Materials how to turn the material in a cotton T-shirt into a source of electrical power.

Starting with a T-shirt from a local discount store, Li's team soaked it in a solution of fluoride, dried it and baked it at high temperature. They excluded oxygen in the oven to prevent the material from charring or simply combusting.

The surfaces of the resulting fibers in the fabric were shown by infrared spectroscopy to have been converted from cellulose to activated carbon. Yet the material retained flexibility; it could be folded without breaking.

"We will soon see roll-up cell phones and laptop computers on the market," Li said. "But a flexible energy storage device is needed to make this possible."

The once-cotton T-shirt proved to be a repository for electricity. By using small swatches of the fabric as an electrode, the researchers showed that the flexible material, which Li's team terms activated carbon textile, acts as a capacitor. Capacitors are components of nearly every electronic device on the market, and they have the ability to store electrical charge.

Moreover, Li reports that activated carbon textile acts like double-layer capacitors, which are also called a supercapacitors because they can have particularly high energy storage densities.

But Li and Bao took the material even further than that. They then coated the individual fibers in the activated carbon textile with "nanoflowers" of manganese oxide. Just a nanometer thick, this layer of manganese oxide greatly enhanced the electrode performance of the fabric. "This created a stable, high-performing supercapacitor," said Li.

This hybrid fabric, in which the activated carbon textile fibers are coated with nanostructured manganese oxide, improved the energy storage capability beyond the activated carbon textile alone. The hybrid supercapacitors were resilient: even after thousands of charge-discharge cycles, performance didn't diminish more than 5 percent.

"By stacking these supercapacitors up, we should be able to charge portable electronic devices such as cell phones," Li said.

Li is particularly pleased to have improved on the means by which activated carbon fibers are usually obtained. "Previous methods used oil or environmentally unfriendly chemicals as starting materials," he said. "Those processes are complicated and produce harmful side products. Our method is a very inexpensive, green process."

[Source]

Highly Transparent Solar Cells for Windows That Generate Electricity

UCLA researchers have developed a new transparent solar cell that is an advance toward giving windows in homes and other buildings the ability to generate electricity while still allowing people to see outside. Their study appears in the journal ACS Nano.

The UCLA team describes a new kind of polymer solar cell (PSC) that produces energy by absorbing mainly infrared light, not visible light, making the cells nearly 70% transparent to the human eye. They made the device from a photoactive plastic that converts infrared light into an electrical current.

"These results open the potential for visibly transparent polymer solar cells as add-on components of portable electronics, smart windows and building-integrated photovoltaics and in other applications," said study leader Yang Yang, a UCLA professor of materials science and engineering, who also is director of the Nano Renewable Energy Center at California NanoSystems Institute (CNSI).

Yang added that there has been intense world-wide interest in so-called polymer solar cells. "Our new PSCs are made from plastic-like materials and are lightweight and flexible," he said. "More importantly, they can be produced in high volume at low cost."

Polymer solar cells have attracted great attention due to their advantages over competing solar cell technologies. Scientists have also been intensely investigating PSCs for their potential in making unique advances for broader applications. Several such applications would be enabled by high-performance visibly transparent photovoltaic (PV) devices, including building-integrated photovoltaics and integrated PV chargers for portable electronics.

Previously, many attempts have been made toward demonstrating visibly transparent or semitransparent PSCs. However, these demonstrations often result in low visible light transparency and/or low device efficiency because suitable polymeric PV materials and efficient transparent conductors were not well deployed in device design and fabrication.

A team of UCLA researchers from the California NanoSystems Institute, the UCLA Henry Samueli School of Engineering and Applied Science and UCLA's Department of Chemistry and Biochemistry have demonstrated high-performance, solution-processed, visibly transparent polymer solar cells through the incorporation of near-infrared light-sensitive polymer and using silver nanowire composite films as the top transparent electrode. The near-infrared photoactive polymer absorbs more near-infrared light but is less sensitive to visible light, balancing solar cell performance and transparency in the visible wavelength region.

Another breakthrough is the transparent conductor made of a mixture of silver nanowire and titanium dioxide nanoparticles, which was able to replace the opaque metal electrode used in the past. This composite electrode also allows the solar cells to be fabricated economically by solution processing. With this combination, 4% power-conversion efficiency for solution-processed and visibly transparent polymer solar cells has been achieved.

"We are excited by this new invention on transparent solar cells, which applied our recent advances in transparent conducting windows (also published in ACS Nano) to fabricate these devices," said Paul S.Weiss, CNSI director and Fred Kavli Chair in NanoSystems Sciences.

Study authors also include Weiss; materials science and engineering postdoctoral researcher Rui Zhu; Ph.D. candidates Chun-Chao Chen, Letian Dou, Choong-Heui Chung, Tze-Bin Song and Steve Hawks; Gang Li, who is former vice president of engineering for Solarmer Energy, Inc., a startup from UCLA; and CNSI postdoctoral researcher Yue Bing Zheng.

[Source]

Tuesday, July 10, 2012

ZPlasma: Plasma Startup Creates High-Energy Light to Make Smaller Microchips

A University of Washington lab has been working for more than a decade on fusion energy, harnessing the energy-generating mechanism of the sun. But in one of the twists of scientific discovery, on the way the researchers found a potential solution to a looming problem in the electronics industry.
To bring their solution to market two UW engineers have launched a startup, Zplasma, that aims to produce the high-energy light needed to etch the next generation of microchips.

"In order to get smaller feature sizes on silicon, the industry has to go to shorter wavelength light," said Uri Shumlak, a UW professor of aeronautics and astronautics. "We're able to produce that light with enough power that it can be used to manufacture microchips."

The UW beam lasts up to 1,000 times longer than competing technologies and provides more control over the million-degree plasma that produces the light.

For more than four decades the technology industry has kept up with Moore's Law, a prediction that the number of transistors on a computer chip will double every two years. This trend has allowed ever-smaller, faster, lighter and less energy-intensive electronics. But it's hit a roadblock: the 193-nanometer ultraviolet light now being used cannot etch circuits any smaller.

The industry has determined that the future standard for making microchips will be 13.5-nanometer light, a wavelength less than 1/14 the current size that should carry the industry for years to come. Such extreme ultraviolet light can be created only from plasmas, which are high-temperature, electrically charged gases in which electrons are stripped from their nuclei.

The electronics industry is trying to produce this extreme ultraviolet light in various ways. One takes a droplet of tin and shoots it with a laser to make plasma that releases a brief spark of light. But so far this spark is too brief. Chip manufacturers use a $100 million machine to bounce light off a series of mirrors and eventually project the light onto a silicon wafer; each step absorbs some of the light's energy.

"Over the past decade, the primary issue with these extreme ultraviolet light sources is they just can't produce enough power," Shumlak said. "It's a stumbling block for the whole semiconductor industry."

Fusion scientists, it turns out, are plasma experts. The hydrogen plasma in the sun is so hot that hydrogen nuclei fuse together and release energy. Scientists around the world, including at the UW, are working to replicate this on Earth. A fusion reactor would use hydrogen as its fuel and emit helium as a waste product, a technically challenging but clean source of energy.

The UW group's specialty is a lower-cost version of a fusion reactor that uses currents flowing through the material, rather than giant magnets, to contain the million-degree plasma. Their method also produces plasma that is stable and long-lived.

"It's a completely different way to make the plasma that gives you much more control," said Brian Nelson, a UW research associate professor of electrical engineering.

The first time they triggered the experiment in 1999, an engineer looking through the glass said, "That was really bright!" That was when the proverbial light bulb went off, Nelson said, and the team began to explore applications for bright high-energy light.

They may have found that application in the microchip industry. Light produced through techniques now being considered by the chip industry generate a spark that lasts just 20 to 50 nanoseconds. Zplasma's light beam lasts 20 to 50 millionths of a second, about 1,000 times longer.

"That translates directly into more light output, more power depositing on the wafer, such that you can move it through in some reasonable amount of time," Shumlak said.

An initial grant from the UW's Center for Commercialization allowed the team to verify that it could produce 13.5-nanometer light. A gift last fall from the Washington Research Foundation helped the team shrink the equipment from the size of a broomstick to a new version the size of a pin, which can produce a sharp beam.

The company was established last year with help from the UW's Center for Commercialization and Henry Berg, a technology entrepreneur who met the researchers through the center's Entrepreneurs in Residence program. Berg is now CEO of Zplasma.

The company is seeking "smart money" from corporate investors who can integrate the new technology with existing industrial processes.

"I hope this gets implemented into the industry and has an impact," Shumlak said.

The group will continue its fusion research project funded by the U.S. Department of Energy. Raymond Golingo, a UW research scientist in aeronautics and astronautics, is co-author of the patent for the technology issued in 2008.

[Source]

Monday, June 25, 2012

The Anatomy Of A Pass, A Quantitative Analysis On Why A VC Passes

Source: TechCrunch
By: Jay Jamison is a partner at BlueRun Ventures.


It is an exciting time for early stage technology company building and venture capital.  Despite some early bumps in Facebook’s recent IPO, we are seeing something of a return in the IPO market, as Facebook, LinkedIn, Groupon, Zynga, Jive and others have gone out.  On the company formation side, founder momentum seems to be surging.  Every week, I learn about about new incubators and startup accelerators getting formed.
Applications are surging to top tier incubators Y Combinator, 500Startups, and TechStars. To be sure, it is an exciting time.
And in this industry, whenever the times are exciting, the storylines and hype cycles start spinning up the siren song that startups are easy.  If all one did was read top tech blogs, you might think that financings materialized out of nowhere, that valuations were getting bid to crazy levels.  And certainly, for some very small number of exceptionally exciting companies, fund-raising happens in a snap.  But it’s not the standard.  The problem with this siren song is simple.  It makes raising money, much less building a company out of nothing, sound easy.
That’s ridonculous.  No matter how robust the current market might be, for the vast majority of early stage companies the core reality is that raising money is hard, if not extremely hard.  And no matter how hard the fund-raising function is, it pales in comparison to the task of actually building a lasting, impactful company.
To support my argument, and ideally more importantly, to serve founding teams planning on fund-raising, I’ve completed a detailed study analyzing every pitch I have heard since the beginning of March 2011.  This analysis attempts to quantify my rationale for why I chose to pass or to invest in a company.
I’m calling this analysis The Anatomy of a Pass, a Quantitative Analysis on Why a VC Passes.  Why this title?  First, the pass is a much more common outcome for any founding team pitching an investor.  Hopefully understanding with some level of quantitative analysis what drives this result will help founders.  Second, I’m specifically relating the title of this work to Brendan Baker’s most excellent and useful “the Anatomy of Seed: An inside look at a $1M seed round.” His work and his thinking are terrific.
A final note: I apologize if this comes across as overly negative.  I’m a venture investor, which means that the glass is always more than half full.  I am insanely fortunate to have a role in this great industry.  I put this together not to critique those who put themselves out there.  It’s meant purely in a spirit of sharing data and analysis.

Methodology

For my analysis, I considered any company I met with for a pitch in person or by phone from March 1, 2011 through May 31, 2012.  I did not include cold calls, unsolicited business plans, brief meetings with founders looking for advice, or catching up with a founder over a beer, unless we met for a pitch later.  Also I did not include all companies who pitched at Demo Days at incubators or startup competitions, but I did include any company from those pitches where I had follow-up meetings.  This gave me a sample size well above 200.
I then rated each company on a 5 point scale (5 is high, 1 is low) across 5 core dimensions:
  1. Traction
  2. Market
  3. Team
  4. Product
  5. Term Sheet
For information on how I built and defined the grading scale, I’ve posted that here.  (From this link, I’ll also post pointers to much of the raw anonymized data.)
I then ran quantitative analysis on this data, seeking to understand the weighting and interplay of Market, Team, Traction, and Product on the likelihood of receiving a Term Sheet.  As a cross-check, I also forced myself at a qualitative level to summarize in 10 words or less why I made each decision.

Findings

Here’s what I found in a first-order analysis of the data:
  • 2% of companies pitching me get an agreement for a term sheet for investment.  Note that a term sheet does not always result in a closed investment from us.  I don’t win them all, sadly.
  • 50% of companies were pitching mobile-centric or mobile-first offerings, which maps to our core focus area as investors at BlueRun.
  • 100% of companies pitching me that received an agreement for a term sheet for investment were pitching mobile-centric or mobile-first offerings.

Analysis

The table above expresses an equation# that can be rewritten like this:
Likelihood of Receiving Term Sheet = -0.355  + 0.349 (Team) + 0.334 (Market) + 0.222 (Traction) + 0.029 (Product)
What this says, in essence is that if you wanted to predict with some likelihood whether a company was going to get a term sheet, from me at least, you could use this function.
So getting rid of the stats-speak, what’s all this mean?  I think it suggests a few things, though again it’s not definitive…

  • Team and Market are by far the two most important factors in gaining a term sheet.  Investors often say “we invest in teams.”  Certainly, teams are really important.  But I think teams attacking big, ambitious, fire-breathers of a market are even more important.  I think this regression, where the Team and Market coefficients are so much more heavily weighted than the others, reinforces this.  To really drive the likelihood of receiving a term sheet, you want to optimize for Team and Market.  Another point to support this: when I summarize each company pitch that I passed on, the most common response I wrote was “questionable market opportunity,” which again speaks to Market.
  • Traction speaks louder than words.  After Team and Market, Traction is the next most important factor to driving towards a term sheet.  In fact, it’s 7 times more valuable than Product at least in this equation.  My interpretation of this finding is that Traction is a reality-maker.  Great Traction showcases evidence of a great Product. Great Traction also helps validate the Team.  And weak Traction undermines whatever exciting demo or product plans might exist.
  • Investments in pre-product companies happens… with great Teams focused on great Markets.  This is not obvious from looking at the data, but if I look at those companies that scored the highest on Likelihood of Term Sheet, not all had high Product or Traction scores.  Some had nothing more than prototypes or ideas of prototypes, and a Seed investment seemed appropriate.  All however had very high scores on Team and Market.
  • Investor fit matters a lot.  Our firm, BlueRun Ventures, has been deeply focused on mobile for years, and we aspire to be the very best of mobile-centric investors.  We talk a lot about this being our focus. Our actions back up our words: every company I’ve agreed to invest in was also focused on services that were mobile-centric.  Fit matters.
To wrap this up, no matter how hot venture financing gets, fund-raising is and always is pretty hard for most founding teams.  Of the more than 200 companies I analyzed, fewer than 2% scored a term sheet from us.  And keep in mind, those 200 are a small subset of the total number of companies that are trying to get onto the calendar to pitch.  My friend and super entrepreneur, Danny Shader, has a great saying which I’ll cite now: “Welcome to the NFL.”  It’s hard.   And of course, if you think raising money is hard, try building a company.
As an attempt to help demystify what makes fund-raising hard, I am providing this analysis. My hope is that this transparency and open sharing of data can be useful, and for those data geeks among us, entertaining. ☺  Happy hunting, and if the community finds this useful, I’ll be happy to track and update this over time.

Peter Thiel - about cleantech investing

Very good article - check it out!

Alternative energy and cleantech have attracted an enormous amount of investment capital and attention over the last decade. Almost nothing has worked as well as people expected. The cleantech experience can thus be quite instructive.[...]

Monday, June 18, 2012

Global Investment in Renewable Energy Powers to Record $257 Billion

Solar generation surged past wind power to become the renewable energy technology of choice for global investors in 2011.

Solar attracted nearly twice as much investment as wind, driving the renewable energy sector to yet another record-breaking year, albeit one beset with challenges for the industry, according to two new reports on renewable energy trends issued June 11 by the United Nations Environment Programme (UNEP) and the Renewable Energy Policy Network for the 21st Century (REN21).

Global Trends in Renewable Energy Investment 2012 is the fifth edition of the UNEP report, based on data from Bloomberg New Energy Finance, and has become the standard reference for global clean energy investment figures.

This year it shows that despite an increasingly tough competitive landscape for manufacturers, total investment in renewable power and fuels last year increased by 17% to a record $257 billion, a six-fold increase on the 2004 figure and 94% higher than the total in 2007, the year before the world financial crisis.

Although last year's 17% increase was significantly smaller than the 37% growth recorded in 2010, it was achieved at a time of rapidly falling prices for renewable energy equipment and severe pressure on fiscal budgets in the developed world.

The REN21 Renewables 2012 Global Status Report, which has become the most frequently referenced report on renewable energy market, industry and policy developments, notes that during 2011 renewables continued to grow strongly in all end-use sectors -- power, heating and cooling and transport. Renewable sources have grown to supply 16.7 % of global energy consumption. Of that, the share provided by traditional biomass has declined slightly while the share sourced from modern renewable technologies has risen.

In 2011, renewable energy technologies continued to expand into new markets: around 50 countries installed wind power capacity, and solar PV capacity moved rapidly into new regions and countries. Solar hot water collectors are used by more than 200 million households as well as in many public and commercial buildings worldwide.

The two publications were launched jointly by Achim Steiner, UNEP Executive Director, Mohamed El-Ashry, Chairman of REN21, Michael Liebreich, Chief Executive of Bloomberg New Energy Finance, and Professor Dr. Udo Steffens, President and CEO of the Frankfurt School of Finance & Management, host of the Frankfurt School -- UNEP Collaborating Centre for Climate & Sustainable Energy Finance.

Highlights 2011

- Total investment in solar power jumped 52% to $147 billion and featured booming rooftop photovoltaic (PV) installations in Italy and Germany, the rapid spread of small-scale PV to other countries from China to the UK and big investments in large-scale concentrating solar thermal (CSP) power projects in Spain and the US.

- The United States surged back to within an inch of the top of the renewables investment rankings, with a 57% leap to $51 billion, as developers rushed to cash in on three significant incentive programs before they expired during 2011 and 2012. After leading the world for two years, China saw its lead over the US shrink to just $1 billion in 2011, as it recorded renewable energy investment of $52 billion, up 17%.

- India's National Solar Mission helped to spur an impressive 62% increase to $12 billion, the fastest investment expansion of any large renewables market in the world. In Brazil, there was an 8% increase to $7 billion.

- Competitive challenges intensified sharply, leading to sharp drops in prices, especially in the solar market -- a boon to buyers but not to manufacturers, a number of whom went out of business or were forced to restructure.

- Renewable power, excluding large hydro-electric, accounted for 44% of all new generating capacity added worldwide in 2011 (up from 34% in 2010). This accounted for 31% of actual new power generated, due to lower capacity factors for solar and wind capacity.

- Gross investment in fossil-fuel capacity in 2011 was $302 billion, compared to $237 billion for that in renewable energy capacity excluding large hydro.

- The top seven countries for renewable electricity capacity excluding large hydro -- China, the United States, Germany, Spain, Italy, India and Japan -- accounted for about 70% of total non-hydro renewable capacity worldwide. The ranking among these countries was quite different for non-hydro capacity on a per person basis: Germany, Spain, Italy, the US, Japan, China and India. By region, the EU was home to nearly 37% of global non-hydro renewable capacity at the end of 2011, China, India and Brazil accounted for roughly one quarter.

- Renewable technologies are expanding into new markets. In 2011, around 50 countries installed wind capacity; solar PV capacity is rapidly moving into new regions and countries; interest in geothermal power has taken hold in East Africa's Rift Valley and elsewhere; interest in solar heating and cooling is on the rise in countries around the world; and the use of modern biomass for energy purposes is expanding in all regions of the globe.

- In the power sector, renewables accounted for almost half of the estimated 208 gigawatts (GW) of electric capacity added globally during the year. Wind and solar photovoltaic (PV) accounted for almost 40% and 30% of new renewable capacity, respectively, followed by hydropower (nearly 25%). By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8% over 2010; renewables comprised more than 25% of total global power-generating capacity (estimated at 5,360 GW in 2011) and supplied an estimated 20.3% of global electricity.

- At least 118 countries, more than half of which are developing countries, had renewable energy targets in place by early 2012, up from 96 one year before, although some slackening of policy support was seen in developed countries. This weakening reflected austerity pressures, particularly in Europe, and legislative deadlock in the US Congress.

- Despite all the additional investments, share prices in the renewable energy sector had a dismal 2011 in the face of overcapacity in the solar and wind manufacturing chains and investor unease about the direction of support policies in both Europe and North America.

"There may be multiple reasons driving investments in renewables, from climate, energy security and the urgency to electrify rural and urban areas in the developing world as one pathway towards eradicating poverty-whatever the drivers the strong and sustained growth of the renewable energy sector is a major factor that is assisting many economies towards a transition to a low carbon, resource efficient Green Economy" says Mr. Steiner.

"This sends yet another strong signal of opportunity to world leaders and delegates meeting later this month at the Rio+20 Summit: namely that transforming sustainable development from patchy progress to a reality for seven billion people is achievable when existing technologies are combined with inspiring policies and decisive leadership," he said.

"It is essential to continue government policies that support and nurture the sector's growth, and to de-escalate damaging trade disputes. Otherwise," he warned, "the low-carbon transition could weaken just at the point when exciting cost reductions are starting to transform the economics."

Says Dr. El-Ashry: "Despite the continuing economic crisis in some key traditional markets, and continuing political uncertainties, more renewable energy was installed last year than ever before. Policies helped to drive renewable energy forward. Policy development and implementation were stimulated by the Fukushima nuclear catastrophe in Japan, along with improvements in renewable energy costs and technologies. As a result, renewable energy is spreading to more countries and regions of the globe. Globally there are more than 5 million jobs in renewable energy industries, and the potential for job creation continues to be a main driver for renewable energy policies."

Bumps in the road

Faced with plunging green energy technology prices and economic austerity measures, many governments slashed their renewable subsidies and allowed other support schemes to expire. The result was a succession of company failures and factory closures in 2011-2012, including five significant solar manufacturers in the US and Germany.

According to Mr. Steiner, "Today's over-capacity situation in some renewables sectors, particularly solar, provides the opportunity to upscale deployment in new markets at costs few thought possible only a few years ago. This is particularly attractive to the many developing countries where much of the population has little or no access to modern energy services."

Says Prof. Dr. Steffens: "Renewables are starting to have a very consequential impact on energy supply, but we're also witnessing many classic symptoms of rapid sectoral growth -- big successes, painful bankruptcies, international trade disputes and more. This is an important moment for strategic policymaking as winners in the new economy form and solidify."

Adds Mr. Liebreich: "We are entering a fascinating period, with clean energy's costs starting to be competitive with fossil fuels. The challenge for policy-makers is to reduce support mechanisms at just the right pace -- too fast and the long-term future of the industry will be harmed. Too slow and you do the world's taxpayers and energy consumers a great disservice."

"Right now we are seeing a lot of pain on the supply-side as prices are being compressed, but it is important to remember than installers, generators and consumers are benefiting. It is all part of the maturing of the sector," he says.

"In 1903, the United States had over 500 car companies, most of which quickly fell by the wayside even as the automobile sector grew into an industrial juggernaut. A century ago, writing off the auto industry based on the failures of weaker firms would have been foolish. Today, the renewable energy sector is experiencing similar growing pains as the sector consolidates."

The industry's image in the investor community has been harmed by a number of high-profile supply-chain company failures, he says. At the same time, he points out, Germany's solar installations hit a new record peak output of 22GW at the end of May -- equivalent to around one quarter of the country's total power demand.

Renewables: an increasingly important contributor to world energy supply

In more and more countries, renewable energy represents a significant and rapidly growing share of total energy supply.

In the United States, renewable energy (including large hydro) provided 12.7% of total domestic electricity in 2011, up from 10.2% in 2010, and 9.3% in 2009. An estimated 39% of electric capacity added in 2011 was from renewable sources, mostly wind power. Renewable energy sources accounted for about 11.8% of U.S. domestic primary energy production, for the first time surpassing the 11.3% from nuclear power).

China again led the world in the installation of wind turbines and was the top hydropower producer and leading manufacturer of PV modules in 2011. Wind power generation increased by more than 48.2% during the year.

In the European Union, renewable energy accounted for more than 71% of total electricity generating capacity additions in 2011, with solar PV alone representing nearly half (46.7%) of new capacity coming on stream.

Germany remained the third biggest market for renewable energy investment. Renewable sources met 12.2% of total final energy consumption and accounted for 20% of electricity consumption (up from 17.2% in 2010 and 16.4% in 2009).

As the world marks the UN "International Year of Sustainable Energy for All," the REN21 Renewables 2012 Global Status Report includes a special focus on rural renewable energy, based on input from local experts working from around the world. Renewable energy is seen increasingly as a means for providing millions of people with a better quality of life through access to modern cooking, heating/cooling and electricity.

The impressive deployment of all renewable energy technologies combined with dramatic cost reductions and significant technology advances in recent years create an important opportunity for rural renewable energy development that points to a brighter future. However, further efforts will be necessary to reach the UN's outlined objectives: annual investment in the rural energy sector needs to increase more than fivefold to provide universal access to modern energy by 2030.

Closing the gap with fossil fuels

The price of all major renewable energy technologies continued to fall in 2011 -- to the point where they are challenging fossil-fuel sources, even before climate, health and other benefits are factored in.

The dominant reason for the price declines was that manufacturer margins were compressed as the industry continued the shift from a period of under-capacity a few years ago, to overcapacity now as growing demand failed to keep up with a surge in supply.

The most spectacular price plunge was in PV cells, whose average price fell from $1.50 per Watt in September 2010, to $1.30 per Watt by January 2011 and $0.60 per Watt by the end of the year, according to the Bloomberg New Energy Finance Solar Price Index. This fed into a fall in PV module prices of nearly 50% between the start of 2011 and the beginning of this year.

Onshore wind turbines showed a similar, although less dramatic, trend. In 2011, prices for turbines to be delivered in the second half of 2013 were 25% lower than for devices delivered in the first half of 2009, according to the Bloomberg New Energy Finance Wind Turbine Price Index.

While 2011 saw significant falls in the costs of generating a MWh of power from onshore wind (down 9%), and from PV technologies (down more than 30%), the cost of electricity generated by fossil-fuel sources changed less in most parts of the world -- despite the sharp falls in US natural gas prices due to the increased use of "fracking," a hotly contested form of resource extraction.

Based on current trends, it is predicted that the average onshore wind project worldwide will be fully competitive with combined-cycle gas turbine generation by 2016 even in the US, as gas prices are expected to rebound to a point where they cover the cost of extraction. At present, this is true only of a minority of wind projects, those that use the most efficient turbines in locations with superior wind resources.

In solar, analysis suggests that the cost of producing power from rooftop PV panels for domestic use is already competitive with the retail (but not the wholesale) daytime electricity price in several countries including Germany, Denmark, Italy and Spain, as well as the state of Hawaii.

Policy environment drives development


REN21's analysis found that stable renewable energy policies continue to be a driving force behind the development of green power capacity.

At least 118 countries -- more than half of them in the developing world -- have now established renewable energy targets. These include shares of total primary energy, total end-use energy, electricity generation (typically 10-30%), heat supply, biofuels as shares of road transport fuels, and total installed capacities for specific technologies.

Support for renewable power generation remains the most popular policy option with at least 65 countries and 27 states now having feed-in-tariffs (FITs).

Most policy activities in 2011 involved revisions to existing FITs, at times under controversy and involving legal disputes.

FIT payments vary widely among technologies and countries but are generally trending downwards, mostly due to lower technology costs than expected.

The reports in full are available at:

Global Trends report: http://fs-unep-centre.org/

REN21 Global Status report: http://www.ren21.net/

[Source]

Carbon Is Key for Getting Algae to Pump out More Oil

Overturning two long-held misconceptions about oil production in algae, scientists at the U.S. Department of Energy's Brookhaven National Laboratory show that ramping up the microbes' overall metabolism by feeding them more carbon increases oil production as the organisms continue to grow.

The findings -- published online in the journal Plant and Cell Physiology on May 28, 2012 -- may point to new ways to turn photosynthetic green algae into tiny "green factories" for producing raw materials for alternative fuels.

"We are interested in algae because they grow very quickly and can efficiently convert carbon dioxide into carbon-chain molecules like starch and oils," said Brookhaven biologist Changcheng Xu, the paper's lead author. With eight times the energy density of starch, algal oil in particular could be an ideal raw material for making biodiesel and other renewable fuels.

But there have been some problems turning microscopic algae into oil producing factories.

For one thing, when the tiny microbes take in carbon dioxide for photosynthesis, they preferentially convert the carbon into starch rather than oils. "Normally, algae produce very little oil," Xu said.

Before the current research, the only way scientists knew to tip the balance in favor of oil production was to starve the algae of certain key nutrients, like nitrogen. Oil output would increase, but the algae would stop growing -- not ideal conditions for continuous production.

Another issue was that scientists didn't know much about the details of oil biochemistry in algae. "Much of what we thought we knew was inferred from studies performed on higher plants," said Brookhaven biochemist John Shanklin, a co-author who's conducted extensive research on plant oil production. Recent studies have hinted at big differences between the microbial algae and their more complex photosynthetic relatives.

"Our goal was to learn all we could about the factors that contribute to oil production in algae, including those that control metabolic switching between starch and oil, to see if we could shift the balance to oil production without stopping algae growth," Xu said.

The scientists grew cultures of Chlamydomonas reinhardtii -- the "fruit fly" of algae -- under a variety of nutrient conditions, with and without inhibitors that would limit specific biochemical pathways. They also studied a mutant Chlamydomonas that lacks the capacity to make starch. By comparing how much oil accumulated over time in the two strains across the various conditions, they were able to learn why carbon preferentially partitions into starch rather than oil, and how to affect the process.

The main finding was that feeding the algae more carbon (in the form of acetate) quickly maxed out the production of starch to the point that any additional carbon was channeled into high-gear oil production. And, most significantly, under the excess carbon condition and without nutrient deprivation, the microbes kept growing while producing oil.

"This overturns the previously held dogma that algae growth and increased oil production are mutually exclusive," Xu said.

The detailed studies, conducted mainly by Brookhaven research associates Jilian Fan and Chengshi Yan, showed that the amount of carbon was the key factor determining how much oil was produced: more carbon resulted in more oil; less carbon limited production. This was another surprise because a lot of approaches for increasing oil production have focused on the role of enzymes involved in producing fatty acids and oils. In this study, inhibiting enzyme production had little effect on oil output.

"This is an example of a substantial difference between algae and higher plants," said Shanklin.

In plants, the enzymes directly involved in the oil biosynthetic pathway are the limiting factors in oil production. In algae, the limiting step is not in the oil biosynthesis itself, but further back in central metabolism.

This is not all that different from what we see in human metabolism, Xu points out: Eating more carbon-rich carbohydrates pushes our metabolism to increase oil (fat) production and storage.

"It's kind of surprising that, in some ways, we're more like algae than higher plants are," Xu said, noting that scientists in other fields may be interested in the details of metabolic switching uncovered by this research.

But the next step for the Brookhaven team will be to look more closely at the differences in carbon partitioning in algae and plants. This part of the work will be led by co-author Jorg Schwender, an expert in metabolic flux studies. The team will also work to translate what they've learned in a model algal species into information that can help increase the yield of commercial algal strains for the production of raw materials for biofuels.

This research was funded by the DOE Office of Science and the DOE Office of Energy Efficiency and Renewable Energy.

[Source]

Monday, May 28, 2012

Scientists Generate Electricity from Viruses

Imagine charging your phone as you walk, thanks to a paper-thin generator embedded in the sole of your shoe. This futuristic scenario is now a little closer to reality. Scientists from the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a way to generate power using harmless viruses that convert mechanical energy into electricity.
 The scientists tested their approach by creating a generator that produces enough current to operate a small liquid-crystal display. It works by tapping a finger on a postage stamp-sized electrode coated with specially engineered viruses. The viruses convert the force of the tap into an electric charge.
Their generator is the first to produce electricity by harnessing the piezoelectric properties of a biological material. Piezoelectricity is the accumulation of a charge in a solid in response to mechanical stress.
The milestone could lead to tiny devices that harvest electrical energy from the vibrations of everyday tasks such as shutting a door or climbing stairs.
It also points to a simpler way to make microelectronic devices. That's because the viruses arrange themselves into an orderly film that enables the generator to work. Self-assembly is a much sought after goal in the finicky world of nanotechnology.
The scientists describe their work in a May 13 advance online publication of the journal Nature Nanotechnology.
"More research is needed, but our work is a promising first step toward the development of personal power generators, actuators for use in nano-devices, and other devices based on viral electronics," says Seung-Wuk Lee, a faculty scientist in Berkeley Lab's Physical Biosciences Division and a UC Berkeley associate professor of bioengineering.
He conducted the research with a team that includes Ramamoorthy Ramesh, a scientist in Berkeley Lab's Materials Sciences Division and a professor of materials sciences, engineering, and physics at UC Berkeley; and Byung Yang Lee of Berkeley Lab's Physical Biosciences Division.
The piezoelectric effect was discovered in 1880 and has since been found in crystals, ceramics, bone, proteins, and DNA. It's also been put to use. Electric cigarette lighters and scanning probe microscopes couldn't work without it, to name a few applications.
But the materials used to make piezoelectric devices are toxic and very difficult to work with, which limits the widespread use of the technology.
Lee and colleagues wondered if a virus studied in labs worldwide offered a better way. The M13 bacteriophage only attacks bacteria and is benign to people. Being a virus, it replicates itself by the millions within hours, so there's always a steady supply. It's easy to genetically engineer. And large numbers of the rod-shaped viruses naturally orient themselves into well-ordered films, much the way that chopsticks align themselves in a box.
These are the traits that scientists look for in a nano building block. But the Berkeley Lab researchers first had to determine if the M13 virus is piezoelectric. Lee turned to Ramesh, an expert in studying the electrical properties of thin films at the nanoscale. They applied an electrical field to a film of M13 viruses and watched what happened using a special microscope. Helical proteins that coat the viruses twisted and turned in response -- a sure sign of the piezoelectric effect at work.
Next, the scientists increased the virus's piezoelectric strength. They used genetic engineering to add four negatively charged amino acid residues to one end of the helical proteins that coat the virus. These residues increase the charge difference between the proteins' positive and negative ends, which boosts the voltage of the virus.
The scientists further enhanced the system by stacking films composed of single layers of the virus on top of each other. They found that a stack about 20 layers thick exhibited the strongest piezoelectric effect.
The only thing remaining to do was a demonstration test, so the scientists fabricated a virus-based piezoelectric energy generator. They created the conditions for genetically engineered viruses to spontaneously organize into a multilayered film that measures about one square centimeter. This film was then sandwiched between two gold-plated electrodes, which were connected by wires to a liquid-crystal display.
When pressure is applied to the generator, it produces up to six nanoamperes of current and 400 millivolts of potential. That's enough current to flash the number "1" on the display, and about a quarter the voltage of a triple A battery.
"We're now working on ways to improve on this proof-of-principle demonstration," says Lee. "Because the tools of biotechnology enable large-scale production of genetically modified viruses, piezoelectric materials based on viruses could offer a simple route to novel microelectronics in the future."

Artificial Leaf Device Produces Hydrogen in Water Using Only Sunlight

Scientists and researchers from the Photovoltaic and Optoelectronic Devices group from the Universitat Jaume I, led by Professor Juan Bisquert, have developed, using nanotechnology, a device with semiconductor materials which generate hydrogen independently in water using only sunlight.

This technology, which has been named artificial photosynthesis, was inspired by photosynthesis which occurs naturally (a process in which plants use sunlight to transform organic material into organic compounds, freeing chemical energy stored in the bonds of the molecule adenosine triphosphate-ATP, and obtaining energetic compounds such as sugars or carbohydrates).
The efficient production of hydrogen using semiconductor materials and sunlight constitutes a crucial challenge to make a paradigm shift towards sustainable energy technology, using inexhaustible resources that are environmentally friendly. "Although the energy efficiency of the device is still not sufficient enough for us to consider marketing it, we are exploring various ways to improve its efficiency and to show that this technology represents a real alternative to meet the energy demands of the 21st century," comments Sixto Giménez, one of the researchers responsible for the investigation.
Hydrogen is an extremely abundant element on Earth's surface, but in combination with oxygen: water (H20). The hydrogen molecule (H2) contains a great amount of energy that can be released when burned due to the reaction with atmospheric oxygen, creating water as the result of this combustion process. In order to convert water into fuel (H2), the H2O must be broken down into its separate components and so that the process can be carried out in a renewable way (without using subsoil fossil fuels), it is necessary to use a device which relies on solar power, and with no other assistance, to provoke the chemical reactions to break the water and form hydrogen in a way similar to leaves on plants. For this reason these devices are named artificial leaves.
The device is submerged in an aqueous solution which, when illuminated with a light source, forms hydrogen gas bubbles. Firstly, the research group used a solution with an oxidizing agent and studied the evolution of hydrogen produced by photons. "Now the biggest challenge," comments Iván Mora, member of the team developing the solution, "is to understand the physical-chemical process which is produced by the semiconductor material and its interface with the aqueous medium in order to streamline the device process."
The development of the artificial leaf is a great scientific challenge due to the difficulty posed by the selection of materials that will be used in the process, working continuously and not decomposing. Currently, the Photovoltaic and Optoelectronic Devices group from the Universitat Jaume I is one of the few research groups on an international level that has shown the viability of a device with these characteristics, together with the North American laboratories from MIT in Boston or NREL in Denver. The research group leader, Juan Bisquert, comments that "in comparison to other devices, that which has been developed by the UJI has the advantage of low production costs and a large collection of incident photons of light, used in the production of hydrogen photons in the infrared spectrum."

[Source]

Wednesday, April 25, 2012

Graphene Boosts Efficiency of Next-Gen Solar Cells

The coolest new nanomaterial of the 21st century could boost the efficiency of the next generation of solar panels, a team of Michigan Technological University materials scientists has discovered.
Graphene, a two-dimensional honeycomb of carbon atoms, is a rising star in the materials community for its radical properties. One of those properties is electrical conductivity, which could make it a key ingredient in the next generation of photovoltaic cells, says Yun Hang Hu, a professor of materials science and engineering. Dye-sensitized solar cells don't rely on rare or expensive materials, so they could be more cost-effective than cells based on silicon and thin-film technologies. But they are not as good at converting light into electricity. In dye-sensitized solar cells, photons knock electrons from the dye into a thin layer of titanium dioxide, which relays them to the anode. Hu's group found that adding graphene to the titanium dioxide increased its conductivity, bringing 52.4 percent more current into the circuit. "The excellent electrical conductivity of graphene sheets allows them to act as bridges, accelerating electron transfer from the titanium dioxide to the photoelectrode," Hu said. The team also developed a comparably foolproof method for creating sheets of titanium dioxide embedded with graphene. It first made graphite oxide powder, then mixed it with titanium dioxide to form a paste, spread it on a substrate (such as glass) and then baked it a high temperatures. "It's low-cost and very easy to prepare," said Hu. But not just any recipe will do. "If you use too much graphene, it will absorb the light in the solar cell and reduce its efficiency," he said. Hu presented a talk on their work, "Graphene for Solar Cells," at the US-Egypt Joint Workshop on Solar Energy Systems, held March 12-14 in Cairo. It was funded by the American Chemical Society Petroleum Research Fund and the National Science Foundation. [Source]

Sunday, April 22, 2012

Solar Cell That Also Shines: Luminescent 'LED-Type' Design Breaks Efficiency Record

To produce the maximum amount of energy, solar cells are designed to absorb as much light from the Sun as possible. Now researchers from the University of California, Berkeley, have suggested -- and demonstrated -- a counterintuitive concept: solar cells should be designed to be more like LEDs, able to emit light as well as absorb it.
The Berkeley team will present its findings at the Conference on Lasers and Electro Optics (CLEO: 2012), to be held May 6-11 in San Jose, Calif. "What we demonstrated is that the better a solar cell is at emitting photons, the higher its voltage and the greater the efficiency it can produce," says Eli Yablonovitch, principal researcher and UC Berkeley professor of electrical engineering. Since 1961, scientists have known that, under ideal conditions, there is a limit to the amount of electrical energy that can be harvested from sunlight hitting a typical solar cell. This absolute limit is, theoretically, about 33.5 percent. That means that at most 33.5 percent of the energy from incoming photons will be absorbed and converted into useful electrical energy. Yet for five decades, researchers were unable to come close to achieving this efficiency: as of 2010, the highest anyone had come was just more than 26 percent. (This is for flat-plate, "single junction" solar cells, which absorb light waves above a specific frequency. "Multi-junction" cells, which have multiple layers and absorb multiple frequencies, are able to achieve higher efficiencies.) More recently, Yablonovitch and his colleagues were trying to understand why there has been such a large gap between the theoretical limit and the limit that researchers have been able to achieve. As they worked, a "coherent picture emerged," says Owen Miller, a graduate student at UC Berkeley and a member of Yablonovitch's group. They came across a relatively simple, if perhaps counterintuitive, solution based on a mathematical connection between absorption and emission of light. "Fundamentally, it's because there's a thermodynamic link between absorption and emission," Miller says. Designing solar cells to emit light -- so that photons do not become "lost" within a cell -- has the natural effect of increasing the voltage produced by the solar cell. "If you have a solar cell that is a good emitter of light, it also makes it produce a higher voltage," which in turn increases the amount of electrical energy that can be harvested from the cell for each unit of sunlight, Miller says. The theory that luminescent emission and voltage go hand in hand is not new. But the idea had never been considered for the design of solar cells before now, Miller continues. This past year, a Bay area-based company called Alta Devices, co-founded by Yablonovitch, used the new concept to create a prototype solar cell made of gallium arsenide (GaAs), a material often used to make solar cells in satellites. The prototype broke the record, jumping from 26 percent to 28.3 percent efficiency. The company achieved this milestone, in part, by designing the cell to allow light to escape as easily as possible from the cell -- using techniques that include, for example, increasing the reflectivity of the rear mirror, which sends incoming photons back out through the front of the device. Solar cells produce electricity when photons from the Sun hit the semiconductor material within a cell. The energy from the photons knocks electrons loose from this material, allowing the electrons to flow freely. But the process of knocking electrons free can also generate new photons, in a process called luminescence. The idea behind the novel solar cell design is that these new photons -- which do not come directly from the Sun -- should be allowed to escape from the cell as easily as possible. "The first reaction is usually, why does it help [to let these photons escape]?" Miller says. "Don't you want to keep [the photons] in, where maybe they could create more electrons?" However, mathematically, allowing the new photons to escape increases the voltage that the cell is able to produce. The work is "a good, useful way" of determining how scientists can improve the performance of solar cells, as well as of finding creative new ways to test and study solar cells, says Leo Schowalter of Crystal IS, Inc. and visiting professor at Rensselaer Polytechnic Institute, who is chairman of the CLEO committee on LEDs, photovoltaics, and energy-efficient photonics. Yablonovitch says he hopes researchers will be able to use this technique to achieve efficiencies close to 30 percent in the coming years. And since the work applies to all types of solar cells, the findings have implications throughout the field. [Source]

Thursday, April 19, 2012

Nature's Billion-Year-Old Battery Key to Storing Energy

New research at Concordia University is bringing us one step closer to clean energy. It is possible to extend the length of time a battery-like enzyme can store energy from seconds to hours, a study published in the Journal of The American Chemical Society shows. Concordia Associate Professor László Kálmán -- along with his colleagues in the Department of Physics, graduate students Sasmit Deshmukh and Kai Tang -- has been working with an enzyme found in bacteria that is crucial for capturing solar energy. Light induces a charge separation in the enzyme, causing one end to become negatively charged and the other positively charged, much like in a battery. In nature, the energy created is used immediately, but Kálmán says that to store that electrical potential, he and his colleagues had to find a way to keep the enzyme in a charge-separated state for a longer period of time. "We had to create a situation where the charges don't want to or are not allowed to go back, and that's what we did in this study," says Kálmán.
Kálmán and his colleagues showed that by adding different molecules, they were able to alter the shape of the enzyme and, thus, extend the lifespan of its electrical potential. In its natural configuration, the enzyme is perfectly embedded in the cell's outer layer, known as the lipid membrane. The enzyme's structure allows it to quickly recombine the charges and recover from a charge-separated state. However, when different lipid molecules make up the membrane, as in Kálmán's experiments, there is a mismatch between the shape of the membrane and the enzyme embedded within it. Both the enzyme and the membrane end up changing their shapes to find a good fit. The changes make it more difficult for the enzyme to recombine the charges, thereby allowing the electrical potential to last much longer. "What we're doing is similar to placing a racecar in on snow-covered streets," says Kálmán. The surrounding conditions prevent the racecar from performing as it would on a racetrack, just like the different lipids prevent the enzyme from recombining the charges as efficiently as it does under normal circumstances. Photosynthesis, which has existed for billions of years, is one of the earliest energy-converting systems. "All of our food, our energy sources (gasoline, coal) -- everything is a product of some ancient photosynthetic activity," says Kálmán. But he adds that the main reason researchers are turning to these ancient natural systems is because they are carbon neutral and use resources that are in abundance: sun, carbon dioxide and water. Researchers are using nature's battery to inspire more sustainable, human-made energy converting systems. For a peek into the future of these technologies, Kálmán points to medical applications and biocompatible batteries. Imagine batteries made of enzymes and other biological molecules. These could be used to, for example, monitor a patient from the inside post-surgery. Unlike traditional batteries that contain toxic metals, biocompatible batteries could be left inside the body without causing harm. "We're far from that right now but these devices are currently being explored and developed," says Kálmán. "We have to take things step by step but, hopefully, we'll get there one day in the not-too-distant future." [Source]

Friday, April 13, 2012

Artificial Photosynthesis Breakthrough: Fast Molecular Catalyzer

Researchers from the Department of Chemistry at the Royal Institute of Technology (KTH) in Stockholm, Sweden, have managed to construct a molecular catalyzer that can oxidize water to oxygen very rapidly. In fact, these KTH scientists are the first to reach speeds approximating those is nature's own photosynthesis. The research findings play a critical role for the future use of solar energy and other renewable energy sources.
Researchers all over the world, including the US, Japan, and the EU, have been working for more than 30 years on refining an artificial form of photosynthesis. The results have varied, but researchers had not yet succeeded in creating a sufficiently rapid solar-driven catalyzer for oxidizing water.

"Speed has been the main problem, the bottleneck, when it comes to creating perfect artificial photosynthesis," says Licheng Sun, professor of organic chemistry at KTH.

But now, together with research colleagues, he has imitated natural photosynthesis and created a record-fast molecular catalyzer. The speed with which natural photosynthesis occurs is about 100 to 400 turnovers per seconds. The KTH have now reached over 300 turnovers per seconds with their artificial photosynthesis.

"This is clearly a world record, and a breakthrough regarding a molecular catalyzer in artificial photosynthesis," says Licheng Sun.

The fact that the KTH researchers are now close to nature's own photosynthesis regarding speed opens up many new possibilities, especially for renewable energy sources.
"This speed makes it possible in the future to create large-scale facilities for producing hydrogen in the Sahara, where there's an abundance of sunshine. Or to attain much more efficient solar energy conversion to electricity, combining this with traditional solar cells, than is possible today," says Licheng Sun.

He points to the problem of skyrocketing gasoline prices, and these advances with the rapid molecular catalyzers can in turn lay the groundwork for many important changes. They make it possible to use sunlight to convert carbon dioxide into various fuels, such as methanol. And, technology can be created to convert solar energy directly into hydrogen. Licheng Sun adds that he and his research colleagues are working hard and pursing intensive research to make this technology reasonably inexpensive.

"I'm convinced that it will be possible in ten years to produce technology based on this type of research that is sufficiently cheap to compete with carbon-based fuels. This explains why Barack Obama is investing billions of dollars in this type of research," says Licheng Sun.
He has conducted research in this field for nearly twenty years, more than half of that time at KTH, and adds that he and many other researchers see efficient catalyzers for oxidation of water as key to solving the solar energy problem.

"When it comes to renewable energy sources, using the sun is one of the best ways to go," says Sun.
The research findings are of such importance that they have recently attracted the attention of the scientific journal Nature Chemistry.
The research pursued by Licheng Sun and his colleagues is funded by the Wallenberg Foundation and the Swedish Energy Agency. They collaborate with researchers at Uppsala University and Stockholm University, and, together with Professor Lars Kloo at KTH, they run a joint research center involving KTH and Dalian University of Technology (DUT) in China.

[Source]

Saturday, April 7, 2012

Algae Biofuels: The Wave of the Future

Researchers at Virginia Bioinformatics Institute have assembled the draft genome of a marine algae sequence to aid scientists across the US in a project that aims to discover the best algae species for producing biodiesel fuel.
The results have been published in Nature Communications.

The necessity of developing alternative, renewable fuel sources to prevent a potential energy crisis and alleviate greenhouse gas production has long been recognized. Various sources have been tried -- corn for ethanol and soybeans for biodiesel, for example. But to truly meet the world's fuel needs, researchers must come up with a way to produce as much biofuel as possible in the smallest amount of space using the least amount of resources.

Enter algae. Unlike other crops like corn or soybeans, algae can use various water sources ranging from wastewater to brackish water and be grown in small, intensive plots on denuded land. While algae may still produce some C02 when burned, it can sequester C02 during growth in a way that fossil-fuel based energy sources obviously can't.

Scientists in VBI's Data Analysis Core (DAC), Robert Settlage, Ph.D., and Hongseok Tae, Ph.D., assisted in the assembly of the genome of Nannochloropis gaditana, a marine algae that may be capable of producing the lipid yields necessary for a viable fuel source.

"Getting the data is now the easy part. What we're doing in the DAC is enabling researchers to move beyond informatics issues of assembly and analysis to regain their focus on the biological implications of their research," said Settlage.

Further analysis revealed that with fairly straightforward genetic modification, N. gaditana should be capable of producing biofuel on an industrial scale, which may be the wave of the future in fuel research and production.

[Source]

Wednesday, March 21, 2012

Researchers Produce Environmentally Friendly Surfactants Using Biotechnology

At present, a large number of daily use products are produced using renewable resources. For example, household cleaners now include active surfactants that are made from sugar and plant oils. Surfactants are found in shampoos, shower gels, skin creams, household cleaners, dishwashing liquids, washing powders and other products.
Till now, most surfactants are produced from crude oil, which has a limited supply. Hence, manufacturers are looking for alternatives and their focus is mainly on detergents produced from sustainable resources.



A team lead by Suzanne Zibek, an engineer and technical biologist at the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB), is now producing surfactants using biotechnological approaches, with the aid of bacteria and fungi. The team has used mannosylerythritol lipids (MEL) and cellobiose lipids (CL) to produce biosurfactants that are effective and environmentally friendly. These materials are produced in a large volume by using smut fungus.

The enhanced structural diversity makes the biosurfactants to stand out from their competing materials. Additionally, these sustainable materials are less toxic and biodegradable. In spite of all these benefits, biological surfactants are used only in a small number of cosmetics and household products because they are expensive and difficult to produce.

Zibek stated that to increase the usage of natural surfactants, it is necessary to improve fermentation yields. To achieve this, the researchers are optimizing the manufacturing process to decrease production costs. Scientists have grown the microorganisms in a bioreactor, which includes a culture medium containing mineral salts, vitamins, oil and sugar. Main aim of the project is to reach high concentrations in the shortest possible time. The team has already achieved concentrations of 100 g/L for MEL and 16 g/L for CL. The next stage of the research is the separation of the biosurfactants from the medium and characterization of the substances depending on applications such as cosmetic, dishwashing liquids, and oven cleaning products. The final stage is the modification of the substances at the enzymatic level.

Source: http://www.fraunhofer.de/

Tuesday, March 20, 2012

Nanotrees Harvest the Sun's Energy to Turn Water Into Hydrogen Fuel

University of California, San Diego electrical engineers are building a forest of tiny nanowire trees in order to cleanly capture solar energy without using fossil fuels and harvest it for hydrogen fuel generation. Reporting in the journal Nanoscale, the team said nanowires, which are made from abundant natural materials like silicon and zinc oxide, also offer a cheap way to deliver hydrogen fuel on a mass scale.

"This is a clean way to generate clean fuel," said Deli Wang, professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering.

The trees' vertical structure and branches are keys to capturing the maximum amount of solar energy, according to Wang. That's because the vertical structure of trees grabs and adsorbs light while flat surfaces simply reflect it, Wang said, adding that it is also similar to retinal photoreceptor cells in the human eye. In images of Earth from space, light reflects off of flat surfaces such as the ocean or deserts, while forests appear darker.

Wang's team has mimicked this structure in their "3D branched nanowire array" which uses a process called photoelectrochemical water-splitting to produce hydrogen gas. Water splitting refers to the process of separating water into oxygen and hydrogen in order to extract hydrogen gas to be used as fuel. This process uses clean energy with no green-house gas byproduct. By comparison, the current conventional way of producing hydrogen relies on electricity from fossil fuels

"Hydrogen is considered to be clean fuel compared to fossil fuel because there is no carbon emission, but the hydrogen currently used is not generated cleanly," said Ke Sun, a PhD student in electrical engineering who led the project.

By harvesting more sun light using the vertical nanotree structure, Wang's team has developed a way to produce more hydrogen fuel efficiently compared to planar counterparts. Wang is also affiliated with the California Institute of Telecommunications and Information Technology and the Material Science and Engineering Program at UC San Diego.

The vertical branch structure also maximizes hydrogen gas output, said Sun. For example, on the flat wide surface of a pot of boiling water, bubbles must become large to come to the surface. In the nanotree structure, very small gas bubbles of hydrogen can be extracted much faster. "Moreover, with this structure, we have enhanced, by at least 400,000 times, the surface area for chemical reactions," said Sun.

In the long run, what Wang's team is aiming for is even bigger: artificial photosynthesis. In photosynthesis, as plants absorb sunlight they also collect carbon dioxide (CO2) and water from the atmosphere to create carbohydrates to fuel their own growth. Wang's team hopes to mimic this process to also capture CO2 from the atmosphere, reducing carbon emissions, and convert it into hydrocarbon fuel.



"We are trying to mimic what the plant does to convert sunlight to energy," said Sun. "We are hoping in the near future our 'nanotree' structure can eventually be part of an efficient device that functions like a real tree for photosynthesis."

The team is also studying alternatives to zinc oxide, which absorbs the sun's ultraviolet light, but has stability issues that affect the lifetime usage of the nanotree structure.

[Source]

Tuesday, February 21, 2012

Engineers Create Tandem Polymer Solar Cells That Set Record for Energy-Conversion

In the effort to convert sunlight into electricity, photovoltaic solar cells that use conductive organic polymers for light absorption and conversion have shown great potential. Organic polymers can be produced in high volumes at low cost, resulting in photovoltaic devices that are cheap, lightweight and flexible.

In the last few years, much work has been done to improve the efficiency with which these devices convert sunlight into power, including the development of new materials, device structures and processing techniques.

In a new study, available online this week in the journal Nature Photonics, researchers at the UCLA Henry Samueli School of Engineering and Applied Science and UCLA's California Nanosystems Institute (CNSI) report that they have significantly enhanced polymer solar cells' performance by building a device with a new "tandem" structure that combines multiple cells with different absorption bands. The device had a certified power-conversion efficiency of 8.62 percent and set a world record in July 2011.

Further, after the researchers incorporated a new infrared-absorbing polymer material provided by Sumitomo Chemical of Japan into the device, the device's architecture proved to be widely applicable and the power-conversion efficiency jumped to 10.6 percent -- a new record -- as certified by the U.S. Department of Energy's National Renewable Energy Laboratory.

By using cells with different absorption bands, tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation. However, the efficiency doesn't automatically increase by simply combining two cells. The materials for the tandem cells have to be compatible with each other for efficient light harvesting, the researchers said.

Until now, the performance of tandem devices lagged behind single-layer solar cells, mainly due to this lack of suitable polymer materials. UCLA Engineering researchers have demonstrated highly efficient single-layer and tandem polymer solar cells featuring a low-band-gap-conjugated polymer specially designed for the tandem structure. The band gap determines the portion of the solar spectrum a polymer absorbs.

"Envision a double-decker bus," said Yang Yang, a professor of materials science and engineering at UCLA Engineering and principal investigator on the research. "The bus can carry a certain number of passengers on one deck, but if you were to add a second deck, you could hold many more people for the same amount of space. That's what we've done here with the tandem polymer solar cell."

To use solar radiation more effectively, Yang's team stacked, in series, multiple photoactive layers with complementary absorption spectra to construct a tandem polymer solar cell. Their tandem structure consists of a front cell with a larger (or high) band gap material and a rear cell with a smaller (or low) band gap polymer, connected by a designed interlayer.

When compared to a single-layer device, the tandem device is more efficient in utilizing solar energy, particularly by minimizing other energy losses. By using more than one absorption material, each capturing a different part of the solar spectrum, the tandem cell is able to maintain the current and increase the output voltage. These factors enable the increase in efficiency, the researchers said.

"The solar spectra is very broad and covers the visible as well as the invisible, the infrared and the UV," said Shuji Doi, research group manager for Sumitomo Chemical. "We are very excited that Sumitomo's low-band gap polymer has contributed to the new record efficiency."

"We have been doing research in tandem solar cells for a much shorter length of time than in the single-junction devices," said Gang Li, a member of the research faculty at UCLA Engineering and a co-author of the Nature Photonics paper. "For us to achieve such success in improving the efficiency in this short time period truly demonstrates the great potential of tandem solar cell technology."

"Everything is done by a very low-cost wet-coating process," Yang said. "As this process is compatible with current manufacturing, I anticipate this technology will become commercially viable in the near future."

This study opens up a new direction for polymer chemists to pursue designs of new materials for tandem polymer solar cells. Furthermore, it indicates an important step towards the commercialization of polymer solar cells. Yang said his team hopes to reach 15 percent efficiency in the next few years.

Yang, who holds UCLA's Carol and Lawrence E. Tannas Jr. Endowed Chair in Engineering, is also faculty director of the Nano Renewable Energy Center at the California NanoSystems Institute at UCLA.

The study was supported by the National Science Foundation, the U.S Air Force Office of Scientific Research, the U.S. Office of Naval Research and the U.S. Department of Energy, together with the National Renewable Energy Laboratory.

[Source]