[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.]
NREL shows graded catalytic-protective layer boosts longevity of high-efficiency photocathodes for renewable hydrogen
January 09, 2017
Researchers at the US Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a method which boosts the longevity of high-efficiency photocathodes in photoelectrochemical water-splitting devices. Their works demonstrates the potential of utilizing a hybridized, heterogeneous surface layer as a cost-effective catalytic and protective interface for solar hydrogen production.
In a paper published in the journal Nature Energy, they show that annealing a bilayer of amorphous titanium dioxide (TiOx) and molybdenum sulfide (MoSx) deposited onto GaInP2 results in a photocathode with high catalytic activity and stability for the hydrogen evolution reaction. The study showed that the annealing results in a graded MoSx/MoOx/TiO2 layer that retains much of the high catalytic activity of amorphous MoSx but with stability similar to crystalline MoS2.
Tesla and Panasonic to manufacture solar cells and modules in Buffalo, NY; 1GW by 2019
December 27, 2016
Tesla and Panasonic finalized an agreement to begin the manufacturing of photovoltaic (PV) cells and modules at the Buffalo, NY factory. These high-efficiency PV cells and modules will be used to produce solar panels in the non-solar roof products. When production of the solar roof begins, Tesla will also incorporate Panasonic’s cells into the many kinds of solar glass tile roofs that Tesla will be manufacturing.
As part of the agreement, Panasonic will cover required capital costs in Buffalo and Tesla is making a long-term purchase commitment from Panasonic. The collaboration extends the established relationship between Tesla and Panasonic, which includes the production of electric vehicle and grid storage battery cells at the Tesla Gigafactory.
On the road to solar fuels and chemicals
In a new paper in the journal Nature Materials (in an edition focused on materials for sustainable energy), a team from Stanford University and SLAC National Accelerator Laboratory has reviewed milestones in the progress of solid-state photoelectrocatalytic technologies toward delivering solar fuels and chemistry.
Noting the “important advances” in solar fuels research, the review team also noted that the largest scientific and technical milestones are still ahead. Following their review, they listed some of the scientific challenges they see as the most important for the coming years.
Hydrogen from sunlight, but as a dark reaction; time-delayed photocatalytic H2 production
December 09, 2016
A team at the Max Planck Institute for Solid State Research, Germany, and collaborators at ETH Zurich and the University of Cambridge, have developed a system that enables time-delayed photocatalytic hydrogen generation—essentially, an artificial photosynthesis system that can operate in the dark. A paper on their work is published in the journal Angewandte Chemie International Edition.
The system uses a carbon nitride-based material that can harvest and store sunlight as long-lived trapped electrons for redox chemistry in the dark. More specifically, the system comprises a partially anionic, cyanamide-functionalized heptazine polymer, which, in the presence of an appropriate electron donor, forms a radical species under irradiation that has a lifetime of more than 10 hours. This ultra-long-lived radical can reductively produce hydrogen in the presence of a hydrogen evolution catalyst in the dark on demand.
Nissan and Eaton broaden xStorage Home energy storage portfolio; 10-year xStorage Buildings deal with Amsterdam ArenA
November 30, 2016
Nissan and power management leader Eaton are broadening their portfolio of xStorage Home residential energy storage solutions—which can use second-life EV batteries—by introducing a range of six product configurations, giving consumers greater choice to meet their energy needs. This announcement comes as pre-orders of xStorage Home begin today in the United Kingdom, Norway and Germany with other European markets to follow in the coming months.
Nissan and Eaton also announced a 10-year deal with Amsterdam ArenA—home of Ajax Football Club and world-famous entertainment venue—to provide back-up power to the arena from second-life Nissan LEAF batteries. The 55,000-seat stadium has hosted numerous high profile concerts and sporting events over the years.
BMW Digital Charging Service optimizes charging and integrates electric vehicles into the energy market
November 28, 2016
BMW i is expanding its engagement in electric mobility with the new BMW Digital Charging Service (DCS)—an intelligent service for predictive, convenient, cost-effective and green power-optimized charging. The Digital Charging Service optimizes charging technology for BMW i and BMW iPerformance vehicles and will be extended in a later phase to other brands. Pilot markets for the new service are Germany and the Netherlands in early 2017, subsequently more countries will follow.
After activation, the service carries out the charging process fully independently and autonomously. The BMW Digital Charging Service is based on two core functions: tariff- and solar-optimized vehicle charging.
Stanford team sets record for solar-to-hydrogen efficiency of solar water splitting: >30%
November 02, 2016
Researchers at Stanford University have demonstrated solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen (STH) efficiency of more than 30%—a new record. The prior record was 24.4%. An open-access paper on their work is published in the journal Nature Communications.
The system consists of two polymer electrolyte membrane electrolyzers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolyzers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolyzers to optimize the system efficiency. The results, the researchers said, demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.
Swiss team develops effective and low-cost solar water-splitting device; 14.2% solar-to-hydrogen efficiency
August 25, 2016
Using commercially available solar cells and none of the usual rare metals, researchers at the Swiss Center for Electronics and Microtechnology (CSEM) and École Polytechnique Fédérale de Lausanne (EPFL) have designed an intrinsically stable and scalable solar water splitting device that is fully based on earth-abundant materials, with a solar-to-hydrogen conversion efficiency of 14.2%.
The prototype system is made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals. The device has already been run for more than 100 hours straight under test conditions. The method, which surpasses previous efforts in terms of stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society.
Lux: Total is leading example of oil supermajor expanding into solar plus storage and distributed generation
August 09, 2016
France-based Total is the first oil supermajor aggressively to enter new areas of business including solar plus storage and distributed generation, notes Lux Research in a new report: “Superpower Darwinism: What Big Oil Can and Cannot Do About Total’s Billion-Dollar Battery Move.”
Even though viable battery companies have become harder and more expensive to buy since Total’s $1-billion acquisition of Saft (earlier post), the oil supermajors—BP, Chevron, ConocoPhillips, Exxon Mobil, Royal Dutch Shell and Total—have cash piles ranging from $5 billion to $30 billion each, despite shrinking profits since 2012 and uncertainty about timing of the eventual recovery of oil prices.
Tesla acquiring SolarCity in $2.6B all-stock deal; expected close of transaction in Q4
August 01, 2016
Tesla and SolarCity reached agreement for the automaker’s purchase of the solar company in an all-stock deal valued at $2.6 billion—slightly less than the original $2.8-billion proposal made by Tesla just over a month ago. (Earlier post.) SolarCity will operate as a wholly-owned subsidiary of Tesla.
The all-stock transaction is valued based on the 5-day volume-weighted average price of Tesla shares as of 29 July 2016. Under the agreement, SolarCity stockholders will receive 0.110 Tesla common shares per SolarCity share, valuing SolarCity common stock at $25.37 per share based on the 5-day volume weighted average price of Tesla shares as of 29 July2016. The original proposal was an exchange ratio of 0.122x to 0.131x shares of Tesla common stock for each share of SolarCity common stock.
Rice team develops “antenna-reactor” plasmonic catalysts for increased energy savings and efficiency in catalytic processes
July 24, 2016
Researchers at Rice University’s Laboratory for Nanophotonics (LANP), with colleagues at Princeton University, have developed a new method for uniting light-capturing photonic nanomaterials and high-efficiency metal catalysts, creating an “antenna-reactor” plasmonic catalyst.
By placing a catalytic reactor particle adjacent to a plasmonic antenna, the highly efficient and tunable light-harvesting capacities of plasmonic nanoparticles can be exploited to increase absorption and hot-carrier generation significantly in the reactor nanoparticles. The modularity of this approach provides for independent control of chemical and light-harvesting properties and paves the way for the rational, predictive design of efficient plasmonic photocatalysts, the researchers suggest in their open-access paper, published in Proceedings of the National Academy of Sciences (PNAS).
Musk’s “Master Plan, Part Deux”; expands Tesla to heavy-duty electric trucks and urban transport; integrated energy generation and storage
July 21, 2016
Master Plan Part 1—public now for ten years—outlined (1) the creation of an expensive low-volume electric car (Roadster) to fund (2) a medium-volume electric car (Model S, X) at a lower price to create (3) an affordable high volume car (Model 3) and (4) provide solar power. Master Plan v2.0 takes Tesla into integrated energy generation and storage (i.e., Tesla’s acquisition of Solar City, earlier post) as well as into heavy-duty electric vehicles and urban transport.
Stanford solar tandem cell shows promise for efficient solar-driven water-splitting to produce hydrogen
June 23, 2016
Researchers at Stanford University, with colleagues in China, have developed a tandem solar cell consisting of an approximately 700-nm-thick nanoporous Mo-doped bismuth vanadate (BiVO4) (Mo:BiVO4) layer on an engineered Si nanocone substrate. The nanocone/Mo:BiVO4 assembly is in turn combined with a solar cell made of perovskite.
When placed in water, the device immediately began splitting water at a solar-to-hydrogen conversion efficiency of 6.2%—matching the theoretical maximum rate for a bismuth vanadate cell. Although the efficiency demonstrated was only 6.2%, the tandem device has room for significant improvement in the future, said Stanford Professor Yi Cui, a principal investigator at the Stanford Institute for Materials and Energy Sciences and senior author of an open access paper describing the work published in Scientific Advances.
Tesla makes ~$2.8B all-stock offer to acquire SolarCity
June 21, 2016
Tesla Motora has made an all-stock offer worth approximately $2.8B to acquire all of the outstanding shares of solar energy provider SolarCity. Subject to completing due diligence, Tesla is proposing an exchange ratio of 0.122x to 0.131x shares of Tesla common stock for each share of SolarCity common stock. This proposal represents a value of $26.50 to $28.50 per share, or a premium of approximately 21% to 30% over the recent closing price of SolarCity’s shares.
Tesla Chairman and CEO Elon Musk is also Chairman of SolarCity; Antonio Gracias, CEO of investor Valor Management Corp., is on both Tesla and SolarCity boards. Musk and Gracias recused themselves from voting on the proposed acquisition at the Tesla Board meeting, and will recuse themselves from the SolarCity Board meeting which will consider the offer.
Harvard “bionic leaf 2.0” exceeds efficiency of photosynthesis in nature; hydrogen and liquid fuels
June 03, 2016
Researchers at Harvard have created a hybrid water splitting–biosynthetic system based on a biocompatible Earth-abundant inorganic catalyst system to split water into molecular hydrogen and oxygen (H2 and O2) at low driving voltages.
Grown in contact with these catalysts, the bacterium Ralstonia eutropha then consumes the produced H2 to synthesize biomass and fuels or chemical products from low CO2 concentration in the presence of O2. The scalable system has a CO2 reduction energy efficiency of ~50% when producing bacterial biomass and liquid fuel alcohols, scrubbing 180 grams of CO2 per kWh of electricity. Coupling this hybrid device to existing photovoltaic systems would yield a CO2 reduction energy efficiency of ~10%, exceeding that of natural photosynthetic systems, the researchers said in their paper published in the journal Science.
New $30M ARPA-E program to produce renewable liquid fuels from renewable energy, air and water
April 26, 2016
The US Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) announced up to $30 million in funding for a new program for technologies that use renewable energy to convert air and water into cost-competitive liquid fuels. (DE-FOA-0001562)
ARPA-E’s Renewable Energy to Fuels through Utilization of Energy-dense Liquids (REFUEL) program seeks to develop technologies that use renewable energy to convert air and water into Carbon Neutral Liquid Fuels (CNLF). The program is focused in two areas: (1) the synthesis of CNLFs using intermittent renewable energy sources and water and air (N2 and CO2) as the only chemical input streams; and (2) the conversion of CNLFs delivered to the end point to another form of energy (e.g. hydrogen or electricity).
U Copenhagen team discovers “reverse photosynthesis” process for the breakdown of biomass for fuels or chemicals production
April 04, 2016
Researchers at the University of Copenhagen have discovered a natural process for the breakdown of biomass they describe as “reverse photosynthesis”—as opposed to the building of biomass as is the case with photosynthesis. Combined with a specific enzyme, the energy of sunlight can break down plant biomass.
Oxidative processes are essential for the breakdown of plant biomass. Lytic polysaccharide monooxygenases (LPMOs)—a class of powerful and widely distributed oxidative enzymes—oxidize the most recalcitrant polysaccharides. These enzymes require extracellular electron donors. In their work, described in an open access paper in the journal Nature Communications, the University of Copenhagen team researchers investigated the effect of using excited photosynthetic pigments as electron donors.
Researchers develop all-weather solar cell that generates power from rain as well as from sun
April 03, 2016
While many technical advances have made solar cells more efficient and affordable, a disadvantage remains in the fact that solar cells produce no power when it’s raining. Now, however, researchers from the Ocean University of China (Qingdao) and Yunnan Normal University (Kunming, China) have developed an all-weather solar cell that is triggered by both sunlight and raindrops by combining an electron-enriched graphene electrode with a dye-sensitized solar cell.
The new solar cell can be excited by incident light on sunny days and raindrops on rainy days, yielding an optimal solar-to-electric conversion efficiency of 6.53% under AM 1.5 irradiation and current over microamps as well as a voltage of hundreds of microvolts by simulated raindrops. Their work is published as a “Very Important Paper” in the journal Angewandte Chemie.
UTA researchers demonstrate one-step solar process to convert CO2 and H2O directly into renewable liquid hydrocarbon fuels
February 23, 2016
Researchers at the University of Texas at Arlington have demonstrated a new solar process for the one-step, gas-phase conversion of CO2 and H2O to C5+ liquid hydrocarbons and O2 by operating the photocatalytic reaction at elevated temperatures and pressures.
The photothermocatalytic process for the synthesis of hydrocarbons—including liquid alkanes, aromatics, and oxygenates, with carbon numbers (Cn) up to C13—ran in a flow photoreactor operating at elevated temperatures (180–200 °C) and pressures (1–6 bar) using a 5% cobalt on TiO2 catalyst and under UV irradiation. A paper describing the process is published in Proceedings of the National Academy of Sciences (PNAS).
New photoelectrode with enhanced visible light absorption for improved solar water-splitting for hydrogen production
February 16, 2016
A team of researchers at Ulsan National Institute of Science and Technology (UNIST), Korea University, and the Korea Advanced Institute of Science and Technology (KAIST) has developed a new type of multilayered (Au NPs/TiO2/Au) photoelectrode that could boost the ability of solar water-splitting to produce hydrogen.
This multilayered photoelectrode is a two-dimensional hybrid metal-dielectric structure, comprising three layers of gold (Au) film; an ultrathin TiO2 layer (20 nm), and gold nanoparticles (Au NPs). In a study, reported in the journal Nano Energy, the team reported that the photoelectrode shows high light absorption of about 90% in the visible range 380-700 nm, as well as significant enhancement in photo-catalytic applications.
Berkeley team develops host-guest nanowires for efficient water splitting and solar energy storage
February 04, 2016
Although metal oxides that absorb visible light are attractive for use as photoanodes in photoelectrosynthetic cells, their performance is often limited by poor charge carrier transport. Researchers from UC Berkeley and colleagues have now addressed this issue by using separate materials for light absorption and carrier transport.
The team reports on their host-guest system of Ta:TiO2|BiVO4 as a photoanode for use in solar water splitting cells in an open-access paper in the journal ACS Central Science. BiVO4 acts as a visible light-absorber and Ta:TiO2 acts as a high surface area electron conductor. The host–guest nanowire architecture allows for simultaneously high light absorption and carrier collection efficiency for efficient solar water oxidation.
New German ecoPtG project seeks to make power-to-gas commercially viable with help of automotive technology
In collaboration with engineering partner IAV, the Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (Centre for Solar Energy and Hydrogen Research Baden-Württemberg, ZSW); the Reiner Lemoine Institut (RLI); and Wasserelektrolyse Hydrotechnik (HT) are researching cost-effective methods of producing hydrogen with the help of automotive technology. In the ecoPtG project, the researchers and engineers are developing an alkaline water electrolyzer with an output of 100 kW. They aim to demonstrate that CO2-neutral hydrogen can be produced in a cost-effective manner and intend to facilitate the storage of electricity.
Electricity is increasingly being generated from fluctuating renewable sources. Solar and wind energy generation depends on the weather and is subject to significant fluctuations. At times, renewable energy production thus temporarily exceeds regional demand. Hydrogen produced according to the power-to-gas method can play a role in resolving this challenge and decarbonizing the transport sector. By converting electricity to gas, solar and wind power become storable. If required, hydrogen can be reconverted or used as environmentally compatible fuel for fuel cell vehicles.