Friday, June 28, 2013
Thursday, June 27, 2013
This article has more to do with Alternative Energy than Renewable Energy, but it may still be of possible interest.
Sandia Labs News Releases
Wednesday, June 26, 2013
Fourth Graders Power Their Classroom with Solar Energy
Energy Intensity of Federal Buildings Slashed 25% in Past Decade
California, Washington Utilities Honored with 2013 Public Power Wind Award
Energy Department, NREL Launch New Research Center for Grid Integration
Smart Grid, Distributed Energy to Strengthen Grid in Hoboken, New Jersey
Tuesday, June 25, 2013
Johnson Controls News Release:
Energy experts push for bipartisan action to support energy efficiency
Johnson Controls' energy efficiency survey reveals 116 rise in energy efficiency, described as America's first fuel
MILWAUKEE, June 25, 2013 /PRNewswire/ -- New research by Johnson Controls, the global leader in delivering solutions that increase energy efficiency in buildings, echoes President Obama's call for more certainty to push clean energy, including energy efficiency, which will save money, reduce carbon pollution and make buildings more valuable. Energy efficiency interest rose 116 percent globally since 2010. Members of congress from both parties agreed that energy efficiency is one element of the climate change they can agree on at the 24th Energy Efficiency Forum in Washington, DC recently.
Click here to view video, fact sheets and presentations about this
"We need public policies and private investment to work together to reduce the market's uncertainty and capture this year's momentum toward a more energy efficient global economy," said Dave Myers, president of Johnson Controls Building Efficiency. The Energy Efficiency Indicator is a global survey of more than 3,000 building owners and operators in 10 countries.
Monday, June 24, 2013
NREL News Release:
NREL Reports 31.1% Efficiency for III-V Solar Cell
Conversion-efficiency mark is a world record for a two-junction solar cell measured under one-sun illumination
Monday, June 24, 2013
The Energy Department's National Renewable Energy Lab has announced a world record of 31.1% conversion efficiency for a two-junction solar cell under one sun of illumination.
NREL Scientist Myles Steiner announced the new record June 19 at the 39th IEEE Photovoltaic Specialists Conference in Tampa, Fla. The previous record of 30.8% efficiency was held by Alta Devices.
The tandem cell was made of a gallium indium phosphide cell atop a gallium arsenide cell, has an area of about 0.25 square centimeters and was measured under the AM1.5 global spectrum at 1,000 W/m2. It was grown inverted, similar to the NREL-developed inverted metamorphic multi-junction (IMM) solar cell – and flipped during processing. The cell was covered on the front with a bilayer anti-reflection coating, and on the back with a highly reflective gold contact layer.
The work was done at NREL as part of DOE's Foundation Program to Advance Cell Efficiency (F-PACE), a project of the Department's SunShot Initiative that aims to lower the cost of solar energy to a point at which it is competitive with other sources including fossil fuels.
At the beginning of the F-PACE project, which aims to produce a 48%-efficient concentrator cell, NREL's best single-junction gallium-arsenide solar cell was 25.7% efficient. This efficiency has been improved upon by other labs over the years: Alta Devices set a series of records, increasing the gallium-arsenide record efficiency from 26.4% in 2010 to 28.8% in 2012. Alta's then-record two-junction 30.8% efficient cell was achieved just two months ago. The new record may not last long either, but "it brings us one step closer to the 48% milestone," said NREL Principal Scientist Sarah Kurtz, who leads the F-PACE project in NREL's National Center for Photovoltaics. "This joint project with the University of California, Berkeley and Spectrolab has provided us the opportunity to look at these near-perfect cells in different ways. Myles Steiner, John Geisz, Iván García and the III-V multijunction PV group have implemented new approaches providing a substantial improvement over NREL's previous results."
"Historically, scientists have bumped up the performance of multijunction cells by gradually improving the material quality and the internal electrical properties of the junctions -- and by optimizing variables such as the bandgaps and the layer thicknesses," NREL Scientist Myles Steiner said. But internal optics plays an underappreciated role in high-quality cells that use materials from the third and fifth columns of the periodic tables – the III-V cells. "The scientific goal of this project is to understand and harness the internal optics," he said.
When an electron-hole pair recombines, a photon can be produced, and if that photon escapes the cell, luminescence is observed – that is the mechanism by which light-emitting diodes work. In traditional single-junction gallium-arsenide cells, however, most of the photons are simply absorbed in the cell's substrate and are lost. With a more optimal cell design, the photons can be re-absorbed within the solar cell to create new electron-hole pairs, leading to an increase in voltage and conversion efficiency. In a multijunction cell, the photons can also couple to a lower bandgap junction, generating additional current, a process known as luminescent coupling.
The NREL researchers improved the cell's efficiency by enhancing the photon recycling in the lower, gallium-arsenide junction by using a gold back contact to reflect photons back into the cell, and by allowing a significant fraction of the luminescence from the upper, GaInP junction to couple into the GaAs junction. Both the open-circuit voltage and the short-circuit current were increased.
Silicon solar cells now dominate the world PV market, but researchers see opportunities for new materials. High-efficiency concentrator cells bolstered by lenses that magnify the power of the sun are attracting interest from utilities because the modules have demonstrated efficiencies well over 30%. And there may be commercial opportunities for one-sun or low-concentration III-V cells if growth rates can be increased and costs reduced.
The same cell should work well when lenses are added to multiply the sun's power. "We expect to observe similar enhancements of the solar cell characteristics when measured under concentrated illumination," Steiner said.
NREL is the U.S. Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for the Energy Department by the Alliance for Sustainable Energy, LLC.
FedEx Press Release:
FedEx Adds 1,900 New Lightweight, Fuel Efficient Vehicles to Fleet
FedEx Makes Significant Progress Towards New Vehicle Fuel Efficiency Goal
Sunday, June 23, 2013
NREL News Release:
NREL Drives Toward the Future with Fuel Cell EVs
June 21, 2013
Efforts currently underway at the Energy Department's National Renewable Energy Laboratory (NREL) are contributing to rapid progress in the research, development and testing of hydrogen and fuel cell technologies.
Building from more than 10 years of support from the Department's Fuel Cell Technologies Office on these topics, NREL has received four Fuel Cell Hybrid Vehicles — Advanced (FCHV-adv) on loan from Toyota. These vehicles will help NREL enhance its research capabilities related to hydrogen fueling infrastructure, renewable hydrogen production, and vehicle performance.
Zero-Emission Fuel Cell Vehicles are Rapidly Evolving
The Toyota vehicle represents another step toward the commercialization of fuel cell electric vehicles (FCEVs). Hydrogen fuel is most often produced using domestic resources and can also be produced using clean renewable energy technologies. When hydrogen is used to power an FCEV, the vehicle has zero tail pipe emissions.
The fuel cells in the Highlander FCHV-adv are representative of the FCEV designs being demonstrated today by automobile companies around the world, making this design an excellent platform for NREL's research activities. Toyota also plans to introduce an FCEV sedan to the U.S. commercial market in 2015.
The zero-emission FCHV-adv, based on a mid-size sport utility vehicle (SUV) platform, has an expected driving range of 325 miles and a fuel economy estimated at 60 miles per gallon of gasoline equivalent (GGE). GGE is a method for measuring the fuel economy of alternative fuels compared to gasoline and represents the amount of an alternative fuel equal to the energy in one liquid gallon of gasoline.
The vehicle is powered by a fuel cell system with light weight, high-pressure hydrogen tanks, an electric motor, a nickel hydride battery, and a power-control unit that determines the split of power from the battery or fuel cell stack to power the vehicle.
NREL to Explore Wide Research Platform
The four FCEVs, on a two-year loan from Toyota as part of a Cooperative Research and Development Agreement (CRADA) with NREL, will be put through a wide platform of testing and analysis at the lab. The vehicles were originally deployed in California in 2009 and have been redeployed to NREL as part of this CRADA.
"We're looking at the whole system — from renewable hydrogen production and vehicle fueling equipment to the impact of driving patterns and behavior on vehicle performance," said Keith Wipke, NREL Laboratory Program Manager for Fuel Cell and Hydrogen Technologies. "Because the vehicles will be four or five years old by the time our loan period ends, we will be able to observe extended durability and reliability, which are critical to the commercial success of these types of vehicles."
Testing will include observing how the vehicles interact with fueling infrastructure and fueling stations that operate at different pressures. While most hydrogen is currently produced from natural gas, at NREL, the vehicles will be fueled with renewable hydrogen made from wind and solar energy as part of the Wind-to-Hydrogen project at the lab's National Wind Technology Center. This project uses wind turbines and solar arrays to power electrolyzers that split water into hydrogen and oxygen.
"These vehicles are emission free, but in most scenarios you still have emissions during the hydrogen production," Wipke said. "If you can make the hydrogen using renewable resources you have the potential for this to be a truly zero-emission fuel source. We're pleased to have the opportunity to further investigate this potential."
Other tests will investigate how drivers interact with the vehicles and influence performance over the test period. Researchers will look at the effects of environment and driving patterns on the vehicles' energy storage and propulsion systems, and demonstrate the vehicles operational capability in real-world activities.
On behalf of the Energy Department, NREL is also planning public outreach and education efforts to better prepare the market for the deployment of these types of vehicles. NREL will offer first-hand exposure to hydrogen and fuel cell vehicle technologies to a variety of audiences, including the general public, academia, and the automotive industry.
Getting Ready for Our Transportation Future
FCEVs use hydrogen, stored in high-pressure tanks made of carbon fiber resin, which is fed to the fuel cell stack where it combines with oxygen from the air. The electricity produced by this chemical reaction is used to power the electric motor and charge the battery.
"For someone like myself who is not an electrochemist, it's truly a fascinating technology," Wipke said. "Hydrogen atoms interact with a membrane coated with small amounts of platinum, which splits the hydrogen into protons and electrons. The protons pass through the membrane, and the electrons go around a different path and do the useful electrical work. Eventually, they meet on the other side with oxygen from the air, and form water, which along with a little heat is the only byproduct of the process."
Fuel cell technologies and the use of hydrogen as a transportation fuel are becoming more visible as automotive manufacturers move these concepts closer to market.
But while these fuel cell technologies are proven and effective, there are still challenges in deploying them, particularly in terms of reducing cost and increasing durability. NREL's long-term durability testing for FCEVs will provide important data toward solutions to these two interrelated challenges.
Another significant issue with deploying these technologies is the need to develop infrastructure around hydrogen production, delivery, and fueling stations.
"We need a lot of infrastructure in place for FCEVs to have widespread consumer acceptance," Wipke said. "Most hydrogen fueling stations use delivered hydrogen instead of on-site production. That is the most economical pathway right now, but with our capabilities here at NREL we are able to fully explore the opportunities for on-site production."
Despite the challenges, Wipke sees a strong future for the FCEV technology.
"Most automakers are committing to get to market with these vehicles before this decade is out. That is encouraging," Wipke said. "The biggest reasons that they are so excited about this option for the future is that range and refueling time are not a concern compared to other new transportation technologies. This makes it a potentially very consumer-friendly transportation technology, one that will function much like what drivers use today."
"It's an exciting opportunity to help move these technologies forward, and we're pleased to have an important role here at NREL."
Learn more about NREL's hydrogen research.
— David Glickson
Saturday, June 22, 2013
GE Press Release:
GE Press Release: