[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.]
NSF/DOE partnership to award up to $18M for H2 production via advanced solar water-splitting technologies; separate DOE solicitation
November 14, 2013
A National Science Foundation and US Department of Energy (DOE) partnership on hydrogen production via solar water-splitting will award (NSF 14-511) up to $18 million to support the discovery and development of advanced materials systems and chemical processes for direct photochemical and/or thermochemical water splitting for application in the solar production of hydrogen fuel.
NSF and DOE are jointly funding this program solicitation issued by the NSF Chemical, Bioengineeering, Environmental and Transport Systems (CBET) Division; NSF expects to make 3 to 5 awards, each of up to 3-years duration. The DOE Fuel Cell Technologies Office also issued a separate solicitation for work a broader range of hydrogen production technologies. (DE-FOA-0000826)
JCAP researchers propose protocol for standardized evaluation of OER catalysts for solar-fuel systems
November 03, 2013
|Protocol for measuring the electrochemically active surface area, catalytic activity, stability, and Faradaic efficiency of heterogeneous electrocatalysts for OER. Credit: ACS, McCrory et al. Click to enlarge.|
Electro-catalytic water splitting to produce hydrogen and oxygen is a key element of solar-fuels devices; identifying efficient catalysts for the oxygen evolution reaction (OER) is critical to their realization. (The OER is efficiency-limiting for direct solar and electrolytic water splitting, rechargeable metal-air batteries, and regenerative fuel cells. Earlier post.) However, notes a team of researchers from the Joint Center for Artificial Photosynthesis at Caltech, current methods employed to evaluate oxygen-evolving catalysts are not standardized, making it difficult to compare the activity and stability of these materials.
To address this issue, the researchers are proposing a protocol to evaluate the activity, stability, and Faradaic efficiency of electro-deposited oxygen-evolving electrocatalysts. In particular, they focus on methods for determining electrochemically active surface area and measuring electrocatalytic activity and stability under conditions relevant to an integrated solar water-splitting device. A paper on their work is published in the Journal of the American Chemical Society.
DOE proposing $100M in FY2014 for 2nd round of funding for Energy Frontier Research Centers
October 01, 2013
US Energy Secretary Ernest Moniz announced a proposed $100 million in FY2014 funding for Energy Frontier Research Centers; research supported by this initiative will enable fundamental advances in energy production and use.
The Department of Energy (DOE) currently funds 46 Energy Frontier Research Centers (EFRCs), which were selected for five-year funding in 2009. (Earlier post.) With support for those centers set to expire in July 2014, DOE has announced a “re-competition” for a second round of funding (DE-FOA-0001010).
EPA recognizes Volkswagen Chattanooga with a Green Power Leadership Award for on-site generation
September 24, 2013
|The 9.5 MW solar park at Chattanooga is owned and operated by Silicon Ranch; VW has signed a 20-year power purchase agreement. Click to enlarge.|
Volkswagen Chattanooga has received a 2013 Green Power Leadership Award from the US Environmental Protection Agency (EPA)—the only automaker to be so recognized. The annual awards recognize the country’s leading green power users for their commitment and contribution to helping advance the development of the nation’s voluntary green power market.
Volkswagen Chattanooga was one of only four organizations nationwide to receive a Leadership Award in the category of on-site generation of green power. (The others were Apple; the County of Santa Clara, CA; and Kaiser Permanete.) The award recognizes EPA Green Power Partners who distinguish themselves using on-site renewable energy applications, such as solar photovoltaic (PV) or landfill gas. Volkswagen Chattanooga is currently generating more than 13 million kWh of green power annually from its on-site 9.5 MW solar energy system, which is enough green power to meet 12% of the organization’s electricity use. (Earlier post.)
Berkeley Lab researchers at JCAP develop unique semiconductor/catalyst construct for production of H2 from sunlight
August 30, 2013
Researchers with the US Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Joint Center for Artificial Photosynthesis (JCAP) have developed a method by which molecular cobalt-containing hydrogen production catalysts can be interfaced with a semiconductor that absorbs visible light.
Coupling the absorption of visible light with the production of hydrogen in one material enables the generation of a fuel simply by illuminating the photocathode, says Gary Moore, a chemist with Berkeley Lab’s Physical Biosciences Division and principal investigator for JCAP. “No external electrochemical forward biasing is required.” Moore is the corresponding author of a paper describing this research in the Journal of the American Chemical Society (JACS).
NREL study suggests cost gap for Western renewables could narrow by 2025
August 26, 2013
A new Energy Department study conducted by the National Renewable Energy Laboratory (NREL) indicates that by 2025 wind and solar power electricity generation could become cost-competitive without federal subsidies, if new renewable energy development occurs in the most productive locations. The cost of generation includes any needed transmission and integration costs.
The benchmark for the study is based on the projected future cost of a new combined-cycle natural gas turbine (CCGT) built in the destination market, with natural gas in 2025 at a nominal price of between $7.50/mmBtu and $8.43/mmBtu. According to the analysis, by 2025 geothermal generation could on average be 12% to 35% higher than CCCGT baseline; solar 1-19% higher; and wind at parity up to 13% higher.
CU-Boulder team develops more efficient isothermal solar-thermal water splitting technique for H2 production
August 02, 2013
A University of Colorado Boulder team has developed a new solar-thermal water-splitting (STWS) system for the efficient production of hydrogen. A paper on their work is published in the journal Science.
STWS cycles have long been recognized as a desirable means of generating hydrogen gas (H2) from water and sunlight, the team notes. Two-step, metal oxide–based STWS cycles generate H2 by sequential high-temperature reduction of a metal oxide catalyst (releasing oxygen atoms) and cooler conditions in which the catalyst is reoxidized by oxygen from water (freeing up hydrogen molecules for collection as hydrogen gas). The temperature swings between reduction and oxidation steps have hobbled STWS’ overall efficiency, however, because of thermal and time losses that occur during the frequent heating and cooling of the metal oxide. The cycling can also limit catalyst lifetime.
Nitrogen-doped graphene nanoplatelets offer high catalytic performance in fuel cells and solar cells; possible replacement for Pt
July 23, 2013
Researchers in South Korea have developed a simple, low-cost and eco-friendly method of creating nitrogen-doped graphene nanoplatelets (NGnPs) with excellent catalytic performance in both dye-sensitized solar cells and fuel cells to replace conventional platinum (Pt)-based catalysts for energy conversion.
A paper on the work, carried out at Ulsan National Institute of Science and Technology (UNIST), is published in Scientific Reports. The UNIST team had previously reported that dry ball-milling can efficiently produce chemically modified graphene particles in large quantities. This new work dry ball mills graphite with nitrogen gas (N2), resulting in the direct fixation of N2 at the edges of graphene nanoplatelets (GnPs).
New $30M ARPA-E program to develop new solar conversion and storage technologies; targeting higher solar penetration in mix
July 17, 2013
ARPA-E is making $30 million available to fund a new program entitled “Full-Spectrum Optimized Conversion and Utilization of Sunlight (FOCUS),” which is aimed at advancing new technologies beyond current photovoltaic (PV) and concentrated solar power (CSP) technologies to exploit the full solar spectrum and reduce the cost of solar energy when the sun is not shining.
The primary goal of this funding opportunity (DE-FOA-0000949) is to provide disruptive new solar conversion and storage technology options to enable a much higher penetration of solar energy generation into the US energy mix.
EPFL/Technion team develops “champion” nanostructures for efficient solar water-splitting to produce hydrogen
July 15, 2013
|Hydrogen bubbles as they appear in a photoelectrochemical cell. © LPI / EPFL. Click to enlarge.|
Researchers from EPFL in Switzerland and Technion-Israel Institue of Technology have developed nanoparticle-based α-Fe2O3 (hematite) electrodes that achieve the highest photocurrent of any metal oxide photoanode for photoelectrochemical water-splitting under 100 mW cm−2 air mass, 1.5 global sunlight. A paper on their work is published in the journal Nature Materials.
With current methods, in which a conventional photovoltaic cell is coupled to an electrolyzer to produce hydrogen, the cost to produce hydrogen from water using the sun is around €15 per kilo at its cheapest, said research leader Dr. Michael Grätzel, Director of the Laboratory of Photonics and Interfaces (LPI) at EPFL and inventor of dye-sensitized photoelectrochemical cells. “We’re aiming at a €5 charge per kilo,” he said.
New catalysts enable photocatalytic version of water gas shift reaction for H2 production
June 18, 2013
Researchers at the Univ. Politécnica de Valencia (Spain) have found that noble metal nanoparticles supported on titanium dioxide or cerium dioxide can catalyze the industrially important water gas shift (WGS) reaction for hydrogen production at ambient temperatures using visible light irradiation. An open access paper on their discovery is published in the RSC journal Energy and Environmental Science.
Currently, most hydrogen is produced via the steam reforming of natural gas, hydrocarbons and coal. Additional amounts of hydrogen are generated by the reaction of CO with water (the water gas shift reaction)—which also leads to the formation of CO2. WGS is an endothermic process typically carried out in industry at high temperatures (about 350 °C) with either an iron oxide- or copper-based catalyst to achieve almost complete CO conversion.
“Project Volt Gas Volt” proposes long-term financing plan to support widespread implementation of power-to-gas systems
June 02, 2013
|Project Volt Gas Volt is based on a long-term financing plan and the use of existing technologies for the large-scale conversion of surplus renewable electricity to methane, with subsequent reuse. Diagram: Isabelle Plat. Click to enlarge.|
Corinne Lepage, Member of the European Parliament (and former French Minister of the Environment) and Professor Robert Bell, Brooklyn University, City University of New York, are proposing Project Volt Gas Volt (VGV) as a technology pathway for using renewable energy to “keep the lights on” on the broadest scale without disruption, together with a long-term financing proposal for the project. Although they are targeting an initial implementation France, they see it as broadly applicable.
Project VGV uses surplus electricity generated by renewable and nuclear sources to produce hydrogen via electrolysis. The hydrogen is combined with CO2 to produce methane, which is pumped into and stored in the existing natural gas grid and used like natural gas for use in power generation, transportation, or other thermal and industrial uses. The concept is the same embodied in Audi’s e-gas project (earlier post), to which the VGV proposal makes continued reference.
German researchers improve catalyst for steam reforming of methanol with salt coating; enabler for renewable energy storage systems
April 19, 2013
Researchers at the University of Erlangen-Nürnberg (Germany) report in the journal Angewandte Chemie their development of an enhanced platinum catalyst for the steam reforming of methanol to release hydrogen.
A central problem of renewable energy technology lies in the great variation of energy generated (i.e., intermittency). One proposed solution is methanol-based hydrogen storage. In this scenario, excess renewable electricity can be used to electrolyze water to produce hydrogen. The hydrogen, in turn, is then reacted with carbon dioxide to make methanol and water, thus allowing it to be stored as a liquid. The hydrogen can be released from the methanol at a later time to power a fuel cell.
PNNL solar thermochemical reaction system can reduce fuel consumption in natural gas power plants by about 20%; future potential for transportation fuels
April 11, 2013
|PNNL’s thermochemical conversion device is installed in front of a concentrating solar power dish. Photo: PNNL. Click to enlarge.|
A new concentrating solar power system developed by Pacific Northwest National Laboratory (PNNL) can reduce the fuel consumption of a modified natural-gas combined-cycle (NGCC) power plant by about 20%. The system converts natural gas into syngas—with higher energy content than natural gas—using a thermochemical conversion device installed in front of a concentrating solar power dish. The power plant then combusts the more energy dense syngas to produce electricity.
PNNL’s system uses a mirrored parabolic dish to direct sunbeams to a central point, where the thermochemical device uses the solar heat to produce syngas form natural gas. About four feet long and two feet wide, the device contains a chemical reactor and several heat exchangers. Concentrated sunlight heats up the natural gas flowing through the reactor’s channels, which hold a catalyst that helps turn natural gas into syngas.
Stanford GCEP awards $6.6M to 7 projects; focus on combining energy conversion with carbon-neutral fuel production
March 13, 2013
Stanford’s Global Climate and Energy Project (GCEP) is awarding $6.6 million to seven research teams—six from Stanford and one from Carnegie Mellon University—to advance research on technologies for renewable energy conversion to electricity or fuels and for capturing CO2 emissions and converting CO2 to fuels.
The 7 awards bring the total number of GCEP-supported research programs to 104, with total funding of approximately $125 million since the project’s launch in 2002.
Stanford study quantifies energetic costs of grid-scale energy storage over time; current batteries the worst performers; the need to improve cycle life by 3-10x
March 10, 2013
|A plot of ESOI for 7 potential grid-scale energy storage technologies. Credit: Barnhart and Benson, 2013. Click to enlarge.|
A new study by Charles J. Barnhart and Sally M. Benson from Stanford University and Stanford’s Global Climate and Energy Project (GCEP) has quantified the energetic costs of 7 different grid-scale energy storage technologies over time. Using a new metric—“Energy Stored on Invested, ESOI”—they concluded that batteries were the worst performers, while compressed air energy storage (CAES) performed the best, followed by pumped hydro storage (PHS). Their results are published in the RSC journal Energy & Environmental Science.
As the percentage of electricity supply from wind and solar increases, grid operators will need to employ strategies and technologies, including energy storage, to balance supply with demand given the intermittency of the renewable supply. The Stanford study considered a future US grid where up to 80% of the electricity comes from renewables.
MIT team outlines path to low-cost solar-to-fuels devices; the artificial leaf
March 05, 2013
A team of researchers at MIT has described a framework for efficiently coupling the power output of a series-connected string of single-band-gap solar cells to an electrochemical process that produces storable fuels. The open access paper, published in the Proceedings of the National Academy of Sciences (PNAS), offers a roadmap for direct solar-to-fuels devices.
The new analysis follows up on 2011 research that produced a proof of concept of an artificial leaf—a small device that, when placed in a container of water and exposed to sunlight, would produce bubbles of hydrogen and oxygen. (Earlier post.) The new work outlines a research program to improve the efficiency of these systems, and could quickly lead to the production of a practical, inexpensive and commercially viable prototype.
Researchers at UC Santa Barbara develop efficient and stable plasmonic water splitter; potential alternative to semiconductor-based solar conversion
February 25, 2013
Researchers at UC Santa Barbara have developed an efficient, autonomous solar water-splitting device based on a gold nanorod array in which essentially all charge carriers involved in the oxidation and reduction steps arise from the hot electrons resulting from the excitation of surface plasmons in the nanostructured gold (plasmonic water-splitter).
In a paper in the journal Nature Nanotechnology, they report that each nanorod functions without external wiring, producing 5x 1013 H2 molecules per cm2 per s under 1 sun illumination (AM 1.5 and 100 mW cm-2), with unprecedented long-term operational stability.
Volkswagen inaugurates 9.5 MW solar park at Chattanooga plant in US; key element of VW Group’s strategic sustainability targets
January 24, 2013
|The 9.5 MW solar park at Chattanooga is owned and operated by Silicon Ranch; VW has signed a 20-year power purchase agreement. Click to enlarge.|
Volkswagen inaugurated its largest solar facility in the world—also the largest solar facility operated by an automaker in the US—at its plant in Chattanooga, TN, which produces the Passat model for North America. The Volkswagen Chattanooga Solar Park has a peak output of 9.5 MW. The power will be used directly in production; solar power will provide up to 12.5% of the electric power required in full-capacity operation and 100% of demand when the plant is not in production.
The new solar park is an integral part of Volkswagen’s worldwide sustainability strategy, which includes generating more power within the Group from renewable energy sources, said Volkswagen Group Officer for the Environment, Energy and New Business Areas, Wolfram Thomas.
Spatially explicit life cycle assessment of 5 sun-to-wheels pathways finds photovoltaic electricity and BEVs offer land-efficient and low-carbon transportation
January 04, 2013
A new spatially-explicit life cycle assessment of five different “sun-to-wheels” conversion pathways—ethanol from corn or switchgrass for internal combustion vehicles (ICVs); electricity from corn or switchgrass for battery-electric vehicles (BEVs); and photovoltaic electricity for BEVs—found a strong case for PV BEVs.
According to the findings by the team from the University of California, Santa Barbara and the Norwegian University of Science and Technology, published in the ACS journal Environmental Science & Technology, even the most land-use efficient biomass-based pathway (i.e., switchgrass bioelectricity in US counties with hypothetical crop yields of more than 24 tonnes/ha) requires 29 times more land than the PV-based alternative in the same locations.
US/China research team proposes “solar energy funnel” to harness photons for electricity; using elastic strain to capture a wider spectrum
November 26, 2012
|A visualization of the broad-spectrum solar energy funnel. Image: Yan Liang. Click to enlarge.|
Researchers from Peking University in China and MIT are proposing using elastic strain as a viable agent to create an optoelectronic material with a spatially varying bandgap that is tunable for use in photovoltaics, photocatalysis and photodetection. In a paper published in Nature Photonics, they propose that a photovoltaic device made from a strain-engineered MoS2 monolayer will capture a broad range of the solar spectrum and concentrate excitons or charge carriers.
The “funnel” is a metaphor: electrons and their counterparts, holes—which are split off from atoms by the energy of photons—are driven to the center of the structure by electronic forces. However, the material actually does assume the shape of a funnel—a stretched sheet of thin material, nano-indented at its center by a microscopic needle that produces a curved, funnel-like shape.