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By Yasha Husain, posted May 14, 2009
Debate #2: Green Energy in the American Southeast
Sandia, Stirling Energy Systems Set New Record, 2.12.08
Photo Courtesy of Sandia National Laboratories
Jeffrey Nelson, Manager, Solar Technologies Department, Concentrating Solar Power Systems, Sandia National Laboratories
In 1999, Jeffrey Nelson co-authored a report that led to the establishment of the DOE Solid-State Lighting Initiative. The report's summary claimed new semiconductor light emitting diodes (LEDs) will "change the way we live, and the way we consume energy."
Worldwide, electricity needed for lighting will be reduced by 50 percent, and overall, electricity consumption will be lowered by 10 percent, the report said.
Nelson had had a long career at Sandia National Laboratories, in Albuquerque, NM, where he began working in 1987. But in 2000 took a hiatus and became Chief Technological Officer for Uniroyal Optoelectronics (UOE) in Florida. There he was put in charge of developing R&D and manufacturing operations. After he left UOE, he began consulting for the DOE on the still new Solid-State Lighting Initiative, and co-founded the business, Medical Lighting Solutions. He is now back at Sandia and is Manager of Concentrating Solar Power Systems in the Solar Technologies Department.
Nelson and I talked on April 17th about the potential of solar technologies in the southeast and he started off by saying he thinks solar water heaters could play an important role since their costs are not as high as concentrated solar and photovoltaics.
Sandia in fact supports a program, Third Party Financed Solar Pools, that's designed to enable people responsible for large scale municipal and commercial pools to purchase, through an agreement with an energy service company (ESCO), renewable energy in the form of solar water heaters.
And, in general, solar water heaters, for homes, buildings and pools, appear set to play a bigger role as a function of green building and energy efficiency upgrades.*
Nelson briefly discussed concentrated solar power plants and photovoltaics with me. He made note of the obvious, which is there are a number of clouds in the southeast compared to the southwest; and said this is essentially what makes CSP plants less practical to build in the southeast.
"The difference (between operating in the southeast vs. the southwest) is you have to have a point source that you can focus the sun on. If there are clouds the overall insulation is going to come down, but if (the clouds) come in front of the sun it won’t work because it has no point source to focus. Essentially, a magnifying glass or mirror needs something to focus a point source. Humidity also scatters the light, which hinders performance. PV (on the other hand) can use both diffuse and direct normal insulation coming in from the sun," Nelson pointed out.
At the same time, Nelson did say CSP would work fine in the southeast. (As noted in the Leitner interview, two plants are planned for Florida, the only place in the southeast where there is an average seven hours of direct radiation a day.)
However, "a CSP plant is 100s of megawatts and it wouldn’t be cost efficient to do on a smaller scale. In general you have to scale-up to cover the costs of the turbine/generator and other large parts," he added. "CSP is utility-scale, not residential, commercial or community. At the best rate, it can be used for concentrating PV."
"Each region has an optimal solution and each solution is regional," Nelson suggested. "In the Midwest, wind is a good bet, but there’s not a lot of population there. In the southwest, there’s a lot of solar, but at the same time population densities are not that high and you need to get the energy to California, right?"
Then there's the importance of integrating the fossil fuel people as an integral part of the grid, because they are the backbone of the current system, he remarked, adding he doesn't think it's realistic to not integrate.
"There are new operating strategies for the fossil generating operation that already incorporate wind and solar," Nelson said.
He gave an example: if a farm loses sun when a cloud moves over its house for 50 percent of a day, for that we have been developing things like the smart grid.
"Because how else do you respond to a fast cloud? There’s a need for a backup system," he said. "When you're talking a solar concentration of 20-30 percent, what we’re all aiming for, it becomes more important to have that backup than when solar accounts for one percent of the grid."
*In a separate conversation with Maria Blais, Coordinator of States Advancing Solar, a Department of Energy initiative, I learned there's begun a greater push for solar water heaters to increasingly be installed in homes and businesses across the country. The technology has improved since the 1980s, at which time incentives for the heaters also ran out. And while federal and state tax policies, and incentives, have favored photovoltaic systems over solar water heaters in recent years, the hope is rising incentives combined with well-targeted outreach and education will encourage more widespread use of the solar thermal heaters. In general, the heaters are a more affordable choice than PV systems able to provide electric power to your house, and they deliver considerable energy savings as well as reductions in carbon emissions. For more information on their costs visit the DOE Energy Savers page and for a thorough listing of federal and state incentives log onto The Database for State Incentives for Renewables (www.dsireusa.org).
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Robert Leitner, Director of South Carolina's Institute for Energy Studies at Clemson University
Nate Blair, Senior Analyst/Group Manager at National Renewable Energy Laboratory in Colorado
Fred Humes, Director of the Education, Training and Research Center at ARC: Hydrogen in Aiken, South Carolina
Todd Stone, Director of Marketing, 3TIER, Global Renewable Energy Assessment and Forecasting
Erika Hartwig Myers, Renewable Energy Coordinator for the South Carolina Energy OfficeChris Daetwyler, Staff Specialist, South Carolina Hydrogen and Fuel Cell Alliance
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Topics featured in this debate:
Offshore Wind
Concentrated Solar
Hydrogen from Solar Electrolysis
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Debate #2: Comments
Received May 17, 2009 9:10 p.m.
James Hansen, "Hydrogen is not an energy source -- and not an effective energy carrier -- don't bet anything on it."
Hansen is Director: NASA Goddard Institute for Space Studies
Hansen's comments were the first to be posted for Debate #2; to view more comments, please link to the page, Debate #2: Comments.
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Comments
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