In the lexicon of renewables, solar and biomass-based energy are usually separated out into two distinct categories: there are different researchers, different grants, different media, different supporters. Generally, people think of solar as a source for electric power, and biofuels as a source for liquid transportation fuels.
But it isn’t always so. Aside from the general observation that nearly all energy systems ultimately are based on today’s or yesterday’s solar energy (only geothermal and nuclear power are distinct exceptions), a new generation of technologies is bringing solar and biofuel technologies closer together.
Symbiosis or Convergence?
There are two main approaches: symbiosis, or co-location, where biofuels and solar projects can be co-located to reduce cost and symbiotically add value to each other, such as a solar thermal system providing renewable energy for the hot water needed for enzymes to do their biofuels processing magic.
The other is convergence, where the focus is to design systems that directly utilize sunlight in the production of fuel – as opposed to traditional biofuels in which sunlight, water and CO2 are used by plants in the creation of biomass, which is later re-converted to liquid fuel.
Solar Liquid Fuels
Convergent technologies are producing something which is not quite the same as a traditional biofuel – yet not quite something entirely different. That’s why we call them solar liquid fuels, but still consider them to be biofuels. At the heart of these systems, generally, is a genetically engineered microbe, a child of synthetic biology, that has been developed to mimic much of photosynthesis.
But in bypassing the creation of biomass entirely, they open up the possibility of a radically simplified process for creating biofuels. At the same time, they find themselves not restricted in their solar efficiencies by the efficiencies of plant biomass.
A Mysterious Set of Technologies
Though we have been covering this topic for more than a year, Digest readers have been generally slow to spot “solar” and think “biofuels”. As we noted in making Solar Liquid Fuels our #4 Most Overlooked Biofuels story of the year, “Our article on solar liquid fuels (now that they have hit the mainstream) was the lowest-rated “read” of all the Top 10 Stories of the Year that we presented in yesterday’s Digest. Suggesting that the technology’s developers still has not quite convinced readers that you can really, really make fuels from sunlight, CO2 and water.
Here are the 10 Solar Liquid Fuel projects on the Digest’s radar (in no ranked order of preference)
1. Powers Energy. In Florida, Powers Energy is developing a plan to co-locate its waste-to-energy technology, used in converting municipal solid waste into ethanol, with a 22,000 panel, 5MW solar energy system. Powers said that it intends to eventually install up to 100MW in its proposed 500-acre array, in collaboration with SunDurance Energy. A goal of the project in Lake County? To reduce the dependence of the waste-to-ethanol project on fossil sources of electricity to power its conversion systems.
2. Sundrop Fuels. In Colorado, one of the most interesting biofuels propositions in quite some time, Sundrop Fuels, emerged from stealth mode earlier this year.
Here’s the scoop: Sundrop Fuels is a solar gasification-based renewable energy company with headquarters in Louisville, Colorado. The company’s advanced high-temperature solar gasification process turns almost any kind of plant material into electricity or liquid transportation fuel.
The Sundrop Fuels process centers on its SurroundSun reactor technology, a proprietary solar-thermal biomass gasifier mounted on a tower and powered by a concentrating mirror field below, creating temperatures of nearly 1,300°C.
Convergent solar biofuels technologies
3. UCLA. In California, researchers from the UCLA Henry Samueli School of Engineering and Applied Science have genetically modified cyanobacteria to produce the liquid fuel isobutanol directly from carbon dioxide and sunlight.
“This new approach avoids the need for biomass deconstruction, either in the case of cellulosic biomass or algal biomass, which is a major economic barrier for biofuel production,” said team leader James C. Liao, Chancellor’s Professor of Chemical and Biomolecular Engineering at UCLA and associate director of the UCLA-Department of Energy Institute for Genomics and Proteomics. “Therefore, this is potentially much more efficient and less expensive than the current approach.”
The technical approach: using Synechoccus elongatus (a cyanobacterium) the team first genetically increased the quantity of the CO2-fixing enzyme RuBisCO. Then they spliced genes from other microorganisms to engineer a strain that intakes carbon dioxide and sunlight and produces isobutyraldehyde gas. The low boiling point and high vapor pressure of the gas allows it to easily be stripped from the system.
4. Arizona State University. In Arizona, state Governor Jan Brewer signed Senate Bill 2370 that will provide individual and corporate tax credits for “solar liquid fuels,” also known as microbial fuels, that create renewable transportation fuels from bacteria using a combination of carbon dioxide, water and sunlight. The tax credit regime commences in 2011 and runs through 2026.
The move comes as an ASU team is competing for a $122 million grant to establish an Energy Innovation Hub that will provide the base for the development of solar liquid fuels — the ASU’s LightSpeed project includes Sandia National Laboratory, Princeton, Yale and the University of Minnesota amongst its partners.
5. University of Massachusetts Amherst. In Massachusetts, more information about the new category of electrofuels has become available from a research team at University of Massachusetts Amherst.
The “Geobacter” team led by microbiologist Derek Lovley said that a combination of solar power, bacteria and carbon dioxide could provide a hybrid of solar and bio-power and also solve the most perplexing problem facing solar energy: energy storage.
Lovley’s microbial electrosynthesis converts solar power directly into chemicals, which are then readily stored with existing infrastructure and distributed on demand, and are 90 percent efficient at turning electrons into fuel without further processing.
Lovley and colleagues published their experimental results and discuss implications in the current, May issue of mBIO, an online journal of the American Society of Microbiology, and are presenting this week at the American Society for Microbiology’s annual meeting in San Diego, which runs from May 23–27.
6. The Electrofuels. In Washington, the U.S. Department of Energy announced that it will award $106 million in ARPA-E funding for 13 research projects that produce advanced biofuels more efficiently from renewable electricity instead of sunlight.
According to the DOE, “Today’s technologies for making biofuels all rely on photosynthesis – either indirectly by converting plants to fuels or directly by harnessing photosynthetic organisms such as algae. This process is less than 1% efficient at converting sunlight to stored chemical energy.
Instead, Electrofuels approaches will use organisms able to extract energy from other sources, such as solar-derived electricity or hydrogen or earth-abundant metal ions. Theoretically, such an approach could be more than 10 times more efficient than current biomass approaches.”
7. University of Cincinnati. In Ohio, a team of University of Cincinnati researchers have described an artificial photosynthetic systems using plant, bacterial and fungus enzymes, nested within a material similar to the foam nesting laid down by Tungara frogs.
The team said that its system does not divert solar energy to maintain life systems and for reproduction, and does not shut down photosynthesis in the presence of high levels of CO2. The team indicated that their ultimate goal was to make their system commercially feasible for carbon capture at coal-fired power plants and other major CO2 emitters.
8. BioCee. In Minnesota, BioCee received a $2.2 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy.
It is listed as the “University of Minnesota Direct Solar Fuels Production of liquid hydrocarbon transportation fuels directly from sunlight, water and CO2 using artificial symbiotic colony of photosynthetic cyanobacteria “.
According to biofuels attorney Todd Taylor, “While that sounds cool enough, it is much more than that. It is a fascinating technology, which immobilizes living, biologically active microorganisms in thin latex coatings, represents a paradigm shift in how living microorganisms are used as biocatalyst.
By focusing on how to immobilize and utilize a variety of microorganisms in the coatings, it is a platform technology that enables the development of novel applications of biocatalysts as well as making existing biocatalysts more competitive by reducing capital and operating costs.
9. The Energy Innovation Hub. In Washington last month , the US Department of Energy announced the award of $228 million, including $122 million to establish an Energy Innovation Hub aimed at developing revolutionary methods to generate fuels directly from sunlight, and $106 million for six projects that convert industrial CO2 emissions into fuel, plastics, cement, and fertilizers.
The Fuels from Sunlight Energy Innovation Hub is one of three Hubs that will receive funding in FY10. The Joint Center for Artificial Photosynthesis (JCAP), will be led by the Cal Tech in partnership with the Lawrence Berkeley National Laboratory.
The goal of the Hub is to develop an integrated solar energy-to-chemical fuel conversion system and move this system from the bench-top discovery phase to a scale where it can be commercialized. JCAP research will be directed at the discovery of the functional components necessary to assemble a complete artificial photosynthetic system: light absorbers, catalysts, molecular linkers, and separation membranes.
The Hub will then integrate those components into an operational solar fuel system and develop scale-up strategies to move from the laboratory toward commercial viability.
In addition to the major partners, Cal Tech and Berkeley Lab, other participating institutions include SLAC National Accelerator Laboratory, Stanford, California; the University of California, Berkeley; the University of California, Santa Barbara; the University of California, Irvine; and the University of California, San Diego.
Last but certainly not least.
10. Joule Unlimited. Last November, Joule Biotechnologies announced that it has achieved direct microbial conversion of CO2 into hydrocarbons via engineered organisms, powered by solar energy.
Joule’s Helioculture process mixes sunlight and CO2 with highly engineered photo synthetic organisms, which are designed to secrete ethanol, diesel or other products.
By moving into a new facility in Leander, Texas, Joule is showing many signs that it will be the first of the solar liquid fuels to reach commercialization.
In Monday’s Digest, we’ll have a special update on Joule and an exclusive interview with CEO Bill Sims on where the company is, where it is headed, and how, and when, and with whom.