[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Caltech team proposes taxonomy for solar fuels generators; different approaches to converting sunlight to chemical fuels
December 22, 2014
Researchers at the California Institute of Technology are proposing a nomenclature and taxonomy for solar fuels generators—devices that harness energy from sunlight to drive the synthesis of chemical fuels. A number of different approaches to this technology are being pursued, many of which can be differentiated by the physical principles on which they are based, according to the Caltech team, led by Dr. Nathan Lewis.
In an open-access paper published in the RSC journal Energy & Environmental Science, Dr. Lewis and colleagues outlined their method of using the source of the asymmetry that separates photogenerated electronics and holes as the basis for their taxonomy. They identify three basic device types: photovoltaic cells, photoelectrochemical cells, and photoelectrosynthetic particulate/molecular photocatalysts.
California makes first investments in $100M energy research & development program; also biogas and H2
December 11, 2014
The California Energy Commission approved its first $10 million to fund Electric Program Investment Charge (EPIC) research and development (R&D) projects during its monthly business meeting today. The Commission also approved grants for the operation of a hydrogen fueling station, biofuel production, geothermal exploration and rooftop solar for schools.
EPIC is a multi-year, research investment program focused on electricity-related innovations, finding new energy solutions and bringing clean energy ideas to the marketplace. The program’s 2012-2014 plan calls for investing $330 million between 2014 and 2015 in innovative technologies that provide benefits to electric ratepayers served by Pacific Gas and Electric Co., Southern California Edison, and San Diego Gas & Electric Co. The seven awards approved will fund applied R&D projects that will develop utility-scale renewable energy generation technologies.
New efficient catalytic system for the photocatalytic reduction of CO2 to hydrocarbons
December 04, 2014
|Photocatalytic reduction products formed on various catalysts. The Au3Cu@STO/TiO2 array (red arrow) was the most reactive photocatalyst in this family to generate hydrocarbons from diluted CO2. Kang et al. Click to enlarge.|
Researchers from Japan’s National Institute for Materials Science (NIMS) and TU-NIMS Joint Research Center, Tianjin University, China have developed a new, particularly efficient photocatalytic system for the conversion of CO2 into CO and hydrocarbons. The system, reported in a paper in the journal Angewandte Chemie, may be a step closer to CO2-neutral hydrocarbon fuels.
More than 130 kinds of photocatalysts have been investigated to catalyze CO2 reduction; of those, strontium titanate (SrTiO3, STO) and titania (TiO2) are two of the most investigated materials. The research team headed by Dr. Jinhua Ye decided to use both, and devised a heteromaterial consisting of arrays of coaxially aligned STO/TiO2 nanotubes.
Toshiba targeting practical implementation of conversion of solar energy and CO2 to feedstock and fuel in 2020s
December 03, 2014
|Mechanism of the technology. Source: Toshiba. Click to enlarge.|
Toshiba Corporation has developed a new technology that uses solar energy directly to generate carbon compounds from carbon dioxide and water, and to deliver a viable chemical feedstock or fuel with potential for use in industry. Toshiba introduced the technology at the 2014 International Conference on Artificial Photosynthesis (ICARP2014) on 26 November.
The long-term goal of the research work is to develop a technology compatible with carbon dioxide capture systems installed at facilities such as thermal power stations and factories, utilizing carbon dioxide to provide stockable and trailerable energy. Towards this, Toshiba said it will further improve the conversion efficiency by increasing catalytic activity, with the aim of securing practical implementation in the 2020s.
Researchers develop free-standing nanowire mesh for direct solar water-splitting to produce H2; new design for “artificial leaf”
|The mesh with BiVO4 nanowire photoanode for water oxidation and Rh-SrTiO3 nanowire photocathode for water reduction produces hydrogen gas without an electron mediator. Credit: ACS, Liu et al. Click to enlarge.|
Researchers from UC Berkeley, Lawrence Berkeley National Laboratory and Nanyang Technological University, Singapore have developed a new technology for direct solar water-splitting—i.e., an “artificial leaf” to produce hydrogen—based on a nanowire mesh that lends itself to large-scale, low-cost production. A paper describing their work is published in the journal ACS Nano.
In the design, semiconductor photocatalysts are synthesized as one-dimensional nanowires, which are assembled into a free-standing, paper-like mesh using a vacuum filtration process from the paper industry. When immersed in water with visible light irradiation (λ ≥ 400 nm), the mesh produces hydrogen gas. Although boosting efficiency remains a challenge, their approach—unlike other artificial leaf systems—is free-standing and doesn’t require any additional wires or other external devices that would add to the environmental footprint.
Stanford’s GCEP awards $10.5M for research on renewable energy; solar cells, batteries, renewable fuels and bioenergy
October 09, 2014
The Global Climate and Energy Project (GCEP) at Stanford University has awarded $10.5 million for seven research projects designed to advance a broad range of renewable energy technologies, including solar cells, batteries, renewable fuels and bioenergy. The seven awards bring the total number of GCEP-supported research programs to 117 since the project’s launch in 2002.
The new funding will be shared by six Stanford research teams and an international group from the United States and Europe. The following Stanford faculty members received funding for advanced research on photovoltaics, battery technologies and new catalysts for sustainable fuels:
OSU hybrid “solar battery” uses photo-assisted charging to improve performance of Li-air batteries; “negative overpotential”
October 03, 2014
Researchers at The Ohio State University have developed a novel strategy to improve the efficiency and performance of non-aqueous lithium-oxygen (Li-air) batteries. The team, led by Yiying Wu, professor of chemistry and biochemistry, integrated a dye-sensitized photoelectrode into a lithium-oxygen battery along with the oxygen electrode to enable “photo-assisted charging” of the Li-air cell.
The basic concept of the integrated solar battery is to use the contribution of the photovoltage to reduce greatly the charging overpotential caused by the difficulty in efficiently electrochemically decomposing lithium peroxide (Li2O2), the discharge product formed on the oxygen electrode. Overpotential otherwise causes low round-trip efficiency as well as degradation of the oxygen electrode and electrolyte. A paper on their work appears in the journal Nature Communications.
EPFL team develops low-cost water splitting cell with solar-to-hydrogen efficiency of 12.3%
September 26, 2014
A team led by Dr. Michael Grätzel at EPFL (Ecole Polytechnique Fédérale de Lausanne) in Switzerland has developed a highly efficient and low-cost water-splitting cell combining an advanced perovskite tandem solar cell and a bi-functional Earth-abundant catalyst.
The combination of the two delivers a water-splitting photocurrent density of around 10 milliamperes per square centimeter, corresponding to a solar-to-hydrogen efficiency of 12.3%. (Currently, perovskite instability limits the cell lifetime.) Their paper is published in the journal Science. In a companion Perspective in the journal, Dr. Thomas Hamann of Michigan State University, who was not involved with the study, called Grätzel’s team’s work “an important step towards achieving [the] goal” of quickly developing alternative sources of energy that can replace fossil fuels.
Solar fuels company Joule looks to partner with Scatec Solar to bring photovoltaic power to Joule production plants
September 05, 2014
Joule, the developer of a direct, single-step, continuous process for the production of solar hydrocarbon fuels (earlier post), has entered into a memorandum of understanding (MoU) with Scatec Solar ASA, a leading, independent solar power producer. In the MoU the parties have agreed to initiate a process to reach specific terms for a partnership, to support the roll-out of Joule production plants featuring photovoltaic power.
The terms of the MoU anticipate that Scatec Solar ASA will become preferred supplier and operator of photovoltaic power installations for Joule plants, with an initial deployment goal of up to 25,000 acres (~10,000 hectares) and a power requirement of 2 gigawatts. A deployment of this scale would generate up to 625 million gallons (~15 million barrels) of ethanol or 375 million gallons (~9 million barrels) of diesel per year, while consuming about 4 million tonnes of industrial waste CO2 annually in the process.
MIT team proposes process to recycle lead-acid batteries to fabricate solar cells
August 18, 2014
Researchers at MIT have devised an environmentally-responsible process to recycle materials from discarded automotive lead-acid batteries to fabricate efficient organolead halide perovskite solar cells (PSCs)—a promising new large-scale and cost-competitive photovoltaic technology. The process simultaneously avoids the disposal of toxic battery materials and provide alternative, readily-available lead sources for PSCs.
The system is described in a paper in the RSC journal Energy and Environmental Science, co-authored by professors Angela M. Belcher and Paula T. Hammond, graduate student Po-Yen Chen, and three others.
Molecular shuttle speeds up hydrogen production by the photocatalytic splitting of water
August 15, 2014
In their latest experiments with semiconductor nanocrystals as light absorbers, physicists led by Professor Jochen Feldmann (Ludwig-Maximilians-Universität München, LMU Munich), in collaboration with a team of chemists under the direction of Professor Andrey Rogach (City University of Hong Kong), have succeeded in significantly increasing the yield of hydrogen produced by the photocatalytic splitting of water.
The crucial innovation, reported in the latest issue of the journal Nature Materials, is the use of a so-called molecular shuttle to markedly improve the mobility of charge carriers in their reaction system.
RIKEN researchers develop bio-inspired catalyst that splits water at neutral pH
August 09, 2014
Plants use photosynthesis to convert carbon dioxide and water into sugars and oxygen. The process starts in a cluster of manganese, calcium and oxygen atoms at the heart of a protein complex called photosystem II, which splits water to form oxygen gas, protons and electrons.
Numerous researchers have attempted to develop synthetic catalysts that mimic this cluster, using light or electricity to convert water into fuels such as hydrogen gas. Unlike plants, however, these artificial catalysts can only split alkaline water, which makes the process less sustainable. Now, researchers at the RIKEN Center for Sustainable Resource Science in Japan have developed a manganese oxide-based catalyst system that can split water efficiently at neutral pH. They report on their work in an open access paper in the journal Nature Communications.
Volkswagen and Audi launch sustainability programs for US introduction of e-Golf BEV and A3 e-tron PHEV; carbon offsets with 3Degrees and solar energy
August 05, 2014
Volkswagen of America, Inc. introduced several e-mobility sustainability initiatives to commence with the US launch of the battery-electric e-Golf (earlier post). These begin with an investment in carbon reduction projects via a partnership with 3Degrees to offset emissions created from e-Golf production, distribution and from the estimated emissions produced from keeping the vehicle charged through the initial 36,000 miles of its life. VoA made the announcement at the Management Briefing Seminar, hosted by the Center for Automotive Research.
Volkswagen of America also selected SunPower as VW’s official solar energy partner; Bosch Automotive Service Solutions as its preferred home-charging and installation services provider; and ChargePoint to provide charging stations to the VW dealer network and to provide US e-Golf owners access to consumers to more than 18,000 charging stations nationwide. The 2015 e-Golf will go on sale later this year at participating dealerships in select states.
DOE awards $100M in 2nd funding round for 32 Energy Frontier Research Centers
June 24, 2014
The US Department of Energy (DOE) is awarding $100 million in the second round of funding for Energy Frontier Research Centers (EFRCs); research supported by this initiative will enable fundamental advances in energy production, storage, and use.
The 32 projects receiving funding were competitively selected from more than 200 proposals. Ten of these projects are new while the rest received renewed funding based both on their achievements to date and the quality of their proposals for future research.
Lux Research: cost of electrofuels remains far from viable
June 09, 2014
|Production costs per barrel of oil equivalent. Source: Lux Research. Click to enlarge.|
The cost of electrofuels—fuels produced by catalyst-based systems for light capture, water electrolysis, and catalytic conversion of carbon dioxide and hydrogen to liquid fuels—remains far away from viable, according to a new analysis by Lux Research.
Building a cost model for the electrolysis process—considering electricity from various routes, such as natural gas and coal as well as renewable electricity from biomass, solar, and wind, as well as generously assuming commercial scale production—Lux found that electrofuels produced from microbes cost $230 per barrel, while a catalytic conversion to make electrofuels produces fuels for $208 per barrel.
Study suggests energy and GHG impacts of synthetic hydrocarbon fuels from CO2 are greater than impacts of existing hydrocarbon fuels
June 06, 2014
|Synthetic fuel production from fuel-combustion-based energy and CO2 (top) and from atmospheric CO2 using solar electricity (bottom). Credit: ACS, van der Giesen et al. Click to enlarge.|
Researchers at the Institute of Environmental Sciences at Leiden University, The Netherlands) have concluded that the energy demand and climate impacts of using CO2 to produce synthetic hydrocarbon fuels by using existing technologies can be greater than the impacts of existing hydrocarbon fuels. Their quantitative lifecycle assessment of the environmental merits of liquid hydrocarbon fuels produced from CO2, water and energy compared to alternative fuel production routes is published in the ACS journal Environmental Science & Technology.
In their study, the researchers evaluated five hypothetical production routes using different sources of CO2 and energy. The team undertook the work specifically to investigate four general arguments that have been proposed in support of such fuels:
GM reduced energy intensity and carbon intensity per vehicle in 2013
May 20, 2014
In 2013, GM reduced the energy-intensity per vehicle manufactured 3.5% from 2012, down to an average 2.22 MW/vehicle from 2.30 MW, according to the company’s just released 2013 sustainability report. GM has set a target of 1.97 MW/vehicle for 2020, a reduction of 20% from the 2010 baseline of 2.47 MW.
The carbon intensity (CI) per vehicle dropped to 0.87 tonnes CO2e/vehicle in 2013, down 1.1% from 0.88 tonnes in 2012. The 2020 target is 0.74 tonnes CO2e, down 20% from the 2010 baseline of 0.93 tonnes. (CI includes all manufacturing and non-manufacturing CO2e emissions reported in the Carbon Disclosure Project (CDP) Scope 1 & 2 categories (earlier post), normalized by vehicle production. These data include data from some GM JVs.)
UC Riverside opening Sustainable Integrated Grid Initiative; integration of solar energy, battery storage and electric and hybrid vehicles
May 15, 2014
|Schematic of the “New Grid Testbed” components, including renewable energy generation, energy storage, smart distribution and electric transportation Click to enlarge.|
The University of California, Riverside is opening its Sustainable Integrated Grid Initiative to research the integration of: intermittent renewable energy, such as photovoltaic solar panels; energy storage, such as batteries; and all types of electric and hybrid electric vehicles. It is the largest renewable energy project of its kind in California.
The first two years of operation is supported by a $2-million contract from the South Coast Air Quality Management District, awarded in January 2012. Construction of the initial testbed platform was also supported by an additional $10 million in contributions from UC Riverside and private partners. The testbed, which is located at UC Riverside’s Bourns College of Engineering Center for Environmental Research and Technology (CE-CERT), includes:
SOLAR-JET project demonstrates solar-driven thermochemical conversion of CO2 and water to jet fuel
April 28, 2014
|SOLAR-JET concentrated thermochemical reactor. Red arrow indicates ceria reduction (oxygen evolution); blue arrow indicates oxidation (fuel production). Click to enlarge.|
The EU-funded SOLAR-JET project has demonstrated the production of aviation kerosene from concentrated sunlight, CO2 captured from air, and water. The process has also the potential to produce any other type of fuel for transport applications, such as diesel, gasoline or pure hydrogen in a more sustainable way.
SOLAR-JET (Solar chemical reactor demonstration and Optimization for Long-term Availability of Renewable JET fuel) uses sunlight in a concentrated solar reactor to convert CO2 and water to syngas (a mixture of hydrogen and CO), which is then processed in a Fischer-Tropsch reactor to aviation kerosene.
New mesoporous crystalline Si exhibits increased rate of H2 production; potential use in Li-ion batteries also
April 11, 2014
|Schematic of mesoporous silicon Image: Donghai Wang/Penn State. Click to enlarge.|
Researchers at Penn State have devised a new process for the bottom-up synthesis of mesoporous crystalline silicon materials with high surface area and tunable primary particle/pore size via a self-templating pore formation process.
The nanosized crystalline primary particles and high surface areas enable an increased rate of photocatalytic hydrogen production from water and extended working life. These advantages also make the mesoporous silicon a potential candidate for other applications, such as optoelectronics, drug delivery systems and even lithium-ion batteries. A paper on their work is published in Nature Communications.
Honda opens Smart Home US in California; produces more energy than it consumes; direct DC-DC EV charging
March 25, 2014
|The Honda Smart Home US integrates a number of technologies, and is managed by Honda’s Home Energy Management System (HEMS). Click to enlarge.|
Honda marked the opening of Honda Smart Home US, showcasing technologies that enable zero net energy living and transportation, including Honda’s home energy management system (HEMS), a proprietary hardware and software system that monitors, controls and optimizes electrical generation and consumption throughout the home’s microgrid.
The home, located on the West Village campus of the University of California, Davis, is capable of producing more energy on-site from renewable sources than it consumes annually, including enough energy to power a Honda Fit EV for daily commuting. Honda Smart Home is expected to generate a surplus of 2.6 MWh of electricity over the course of a year, while a comparable home will consume approximately 13.3 MWh. The home’s occupant will be able to use less than half of the energy of a similarly sized new home in the Davis area for heating, cooling and lighting. The home is also three times more water-efficient than a typical US home.
JCAP hybrid photocathode material shows promising performance in conversion of solar energy to hydrogen
March 09, 2014
A new study by Berkeley Lab researchers at the Joint Center for Artificial Photosynthesis (JCAP) shows that nearly 90% of the electrons generated by a new hybrid photocathode material designed to store solar energy in hydrogen are being stored in the target hydrogen molecules (Faradaic efficiency).
Gary Moore, a chemist and principal investigator with Berkeley Lab’s Physical Biosciences Division, led an efficiency analysis study of the material he and his research group have developed for catalyzing the production of hydrogen fuel from sunlight. (Earlier post.) This material, a p-type (100) gallium phosphide (GaP) semiconductor functionalized with molecular hydrogen-producing cobaloxime catalysts via polymer grafting, has the potential to address one of the major challenges in the use of artificial photosynthesis to make renewable solar fuels.
Researchers developing DC micro smart grid for charging EV fleets; Li-ion, redox flow batteries and renewables
March 07, 2014
|Up to 30 electric vehicles at a time can recharge in Fraunhofer IAO’s parking garage. Click to enlarge.|
A team from Fraunhofer Institute for Industrial Engineering IAO, together with Daimler AG and the Institute for Human Factors and Technology Management at the University of Stuttgart, is developing both the charging infrastructure and the energy management systems required to manage large fleets of EVs in a project called charge@work.
The aim of charge@work is to design a micro smart grid (MSG) capable of supplying the EV fleet with electricity produced exclusively from renewable sources. This year will see the installation of a photovoltaic unit and a small wind power system at the Fraunhofer Institute Center Stuttgart IZS, where up to 30 electric vehicles at a time can recharge at AC charge spots in the Fraunhofer Campus parking garage.
M5BAT 5MW storage system integrates multiple battery technologies
February 24, 2014
The E.ON Energy Research Center at RWTH Aachen University, E.ON electric utility company, battery manufacturers Exide and beta-motion and inverter manufacturer SMA Solar Technology AG (SMA) have joined forces to build the first multi-technology, modular large-scale 5MW battery storage system.
The unique feature of the M5BAT (Modular Multimegawatt, Multitechnology Medium-Voltage Battery Storage System) storage system lies in its modular design, which combines different battery technologies for optimal use. It consists of lithium-ion batteries to meet short-term demand; high-temperature batteries to supply power for several hours; and lead-acid batteries when the average discharge time is one hour or less.
ARPA-E awarding $30M to 12 hybrid solar projects; conversion and storage
February 07, 2014
The US Department of Energy (DOE) Advanced Research Projects Agency - Energy (ARPA-E) is awarding $30 million in funding to 12 projects through its Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS) program, which is aimed at developing new hybrid solar energy converters and hybrid energy storage systems that can deliver low-cost, high-efficiency solar energy on demand. (Earlier post.)
Under the FOCUS program, projects will develop advanced solar converters that turn sunlight into electricity for immediate use, while also producing heat that can be stored at low cost for later use as well as innovative storage systems that accept both heat and electricity from variable solar sources.
Israeli company reports successful stage 1 testing of solar CO2-to-fuels technology
January 26, 2014
Israel-based NewCO2Fuels (NCF), a subsidiary of GreenEarth Energy Limited in Australia, reported completion of stage 1 testing of its proof-of-concept system for the conversion of CO2 into fuels using solar energy. NewCO2Fuels was founded in 2011 to commercialize a technology developed by Prof. Jacob Karni’s laboratory at the Weizmann Institute of Science.
In passing the Stage 1 testing, NCF demonstrated technology that successfully dissociates CO2 into CO and oxygen in a heating environment, simulating the industrial waste heat sources that will be used as one of two energy sources in the commercial product. Importantly, the company said, the dissociation rate of the system was increased by a factor of 200 and the cost was reduced by a factor of 34, relative to the original dissociation apparatus demonstrated in 2010 at the laboratories of the Weizmann Institute of Science in Israel.
Harvard team demonstrates new metal-free organic–inorganic aqueous flow battery; potential breakthrough for low-cost grid-scale storage
January 11, 2014
|Cell schematic. Discharge mode is shown; the arrows are reversed for electrolytic/charge mode. AQDSH2 refers to the reduced form of AQDS. Huskinson et al. Click to enlarge.|
Researchers at Harvard have demonstrated a metal-free organic–inorganic aqueous flow battery—a quinone–bromide flow battery (QBFB)—as an example of a class of energy storage materials that exploits the favorable chemical and electrochemical properties of a family of molecules known as quinones. Quinones are naturally abundant, inexpensive, small organic molecules, and similar to molecules that store energy in plants and animals. The new flow battery developed by the Harvard team already performs as well as vanadium flow batteries, with chemicals that are significantly less expensive and with no precious-metal electrocatalyst.
In a paper in Nature, they suggest that the use of such redox-active organic molecules instead of redox-active metals represents a new and promising direction for realizing massive electrical energy storage at greatly reduced cost. The technology could fundamentally transform the way electricity is stored on the grid, making power from renewable energy sources such as wind and sun far more economical and reliable.
Ford unveils C-MAX Solar Energi concept; “plug-in” hybrid not dependent on electric grid can fully recharge from sun
January 02, 2014
Ford Motor Company announced the C-MAX Solar Energi Concept, a sun-powered hybrid vehicle that can deliver the efficiency of a plug-in hybrid without depending on the electric grid for recharging. Instead of recharging its battery from an electrical outlet, Ford C-MAX Solar Energi Concept uses a special Fresnel lens-based solar concentrator as a stationary canopy working with solar panels on the vehicle roof to recharge directly from the sun.
The concept vehicle uses a day’s worth of sunlight to deliver the same performance as the conventional C-MAX Energi plug-in hybrid (earlier post), which draws its power from the electric grid. Ford C-MAX Energi gets a combined EPA-estimated 108 MPGe city and 92 MPGe highway, for a combined 100 MPGe. C-MAX Solar Energi Concept, which will be shown at the 2014 International CES in Las Vegas, is a collaborative project of Ford, SunPower Corp. and Georgia Tech.