[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.]
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.
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.
Clariant supplying SNG catalyst for methanation unit in Audi’s new “Power-to-Gas” plant
October 21, 2013
Clariant, a global provider of specialty chemicals, has supplied a proprietary CO2-SNG (synthetic natural gas) catalyst for the methanation unit of Audi’s new power-to-gas facility in Werlte, Germany. (Earlier post.)
The “e-gas plant” was started up in June this year and is part of Audi’s sustainability initiative. The plant, which can convert six megawatts of input power, will utilize renewable electricity for electrolysis, producing oxygen and hydrogen, the latter which could one day power fuel-cell vehicles. Because there is not yet a widespread hydrogen infrastructure, however, the hydrogen is reacted with CO2 in a methanation unit to generate renewable synthetic methane, or Audi e-gas.
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.
GE using Large Eddy Simulation on Sandia’s Red Mesa to lay groundwork for quieter wind turbine blades with better power yield
August 15, 2013
|Transition of flow to turbulence on a wind-turbine airfoil; isosurfaces of vorticity from a Large Eddy Simulation (LES). Credit: GE Global Research. Click to enlarge.|
GE Global Research, the technology development arm of the General Electric Company, recently completed a research project in partnership with Sandia National Laboratories that could significantly affect the design—and thus the noise and power output—of future wind turbine blades.
A 1 decibel quieter rotor design would result in a 2% increase in annual energy yield per turbine. With approximately 240 GW of new wind installations forecasted globally over the next five years, a 2% increase would create 5 GW of additional wind power capacity—enough to power every household in New York City, Boston, and Los Angeles, combined, GE Research noted.
“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.
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.