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By Yasha Husain, posted May 14, 2009
Debate #2: Green Energy in the American Southeast
Wind turbine and sky
Photo Courtesy of Northern Power Systems/National Renewable Energy Laboratory
Robert Leitner, Director of South Carolina's Institute for Energy Studies at Clemson University
When posed the question about a hybrid system of renewables for the southeast, Robert Leitner, Director of South Carolina’s Institute for Energy Studies at Clemson University, said it’s conceivable to have in his state an electrical system primarily reliant on offshore wind and non-utility scale, concentrated solar power (CSP).
The offshore wind turbines would operate a distance from the coast; connect with the local grid (offsetting the need for more expensive transmission lines to move wind power from the Midwest); and serve as a replacement for other carbon-emitting, centralized power sources, like coal and gas turbine plants. Offshore wind, Leitner said, could provide customers with 50 percent of their electricity and space and water heating and cooling needs.
Regarding the benefits of building offshore wind farms up and down the East Coast, Leitner commented:
The wind potential on the East Coast extends all the way up the coast of Georgia to the coast of Maine. South Carolina has the ability to produce about twice the amount of energy than it consumes each year (with offshore wind).
The biggest issue is intermittency, the question of what do I do when the wind is not blowing?
One of the things they’ve found with the windfarms they’ve built up and down the southwest is that while the wind may be strong in one area, it’s never widespread. Our hope would be that it would spread in both directions, from Georgia, and up the coast to Maine. This would help us to bring wind energy in.
If you look at offshore wind you’re looking for three things generally: 1) how high are the wind speeds (off of South Carolina they’re pretty good) 2) how deep are the waters (typically you want 30 meters or less deep; we have the continental shelf and as a result of that the drops don’t drop off very quickly) and 3) you want the distance where you go to capture the wind energy to be less than 50 miles.In the Pacific Ocean, the depths drop off very quickly, so we’re kind of unique in the offshore wind area (in the East).
Concentrated solar projects, Leitner thought, could perhaps provide the other 50 percent of home and building energy requirements, together with things like solar water heaters, geothermal units, and hydrogen. Non-utility scale CSP plants, he acknowledged, would each carry far less of a load than the utility-scale CSP plants you have in the southwest and in Spain right now. But the smaller plants, Leitner suggested, could provide more direct power to pocket communities of say 400 to 500 homes, or less.
An advantage of these non-utility scale systems, including Sopogy's, which ranges from 250 kilowatts to 20 megawatts, is they don't incur the loss in load upfront that energy currents running from utility-scale systems do. The energy more localized plants produce is delivered straight to customers rather than being traversed over high voltage transmission lines for many miles. This, Leitner said, might make up the difference or loss from constructing non-utility versus utility scale solar plants, at least in South Carolina.
There are two companies, Florida Power & Light Company and Torresol, both planning to build large-scale CSP plants in Florida in the near future. But it's not currently feasible to build the same size utility-scale plants in South Carolina and other parts of the southeast because, on average, a state like South Carolina receives close to four and a half hours of direct radiation, or sunlight, per day, versus the seven hours required to run a utility-scale, concentrated solar plant. Only select parts of Florida receive the required seven hours of direct radiation each day.When I asked Leitner about photovoltaics, he said the problem with traditional PV panels is that when compared with concentrated solar they are going to be cost-prohibitive in the southeast. Costs for panels would likely need to come down by a factor of 6 from 35 cents a kilowatt hour in order that they become competitive, he said.
"It becomes very expensive to store solar energy with photovoltaics so that you can build dispatchable power. It would be advantageous if there were between wind and solar 24 hours of stored energy," Leitner added.
He gave the following analogy:
If you take a thermos bottle and put it on your desk, and take a battery and put it on your desk, they both can hold the same amount of electricity. But the thermos costs you $5 and the battery costs you $100. They both store the same amount of energy, but the one is much more expensive to produce.
I interviewed Leitner on April 8th after he had recently submitted a study of offshore wind power and its transmission to the state-run utility Santee Cooper. Unfortunately, he was not at liberty to discuss the details of that report, as it was being reviewed. Instead, he answered a number of questions about the East Coast's potential for offshore wind and pointed me in the direction of the 20% Wind Power by 2030 report published by the Department of Energy in 2008, as well as the Danish Offshore Wind Key Environmental Issues report from 2006.
The Institute for Energy Studies Leitner directs also recently completed a study looking at the best alternative energy solutions for the Eastern Band of Cherokee Indians located on Tribal Lands in North Carolina. The Tribal Lands are a part of the Appalachian Mountain chain and are situated in one of the few inland sections of the Carolinas considered to have good wind resources. Leitner's team concluded, in step with the Cherokees, that wind power and conversion of municipal waste streams make the most sense there and are both environmentally-friendly and cost-effective energy options.
Though Leitner's primary focus for the studies he's just completed has been wind energy, in the process of doing his work he has also been looking at the solar potential in the region. He said he has learned quite a bit from speaking with plenty of companies that sell solar systems, too. And ultimately, Leitner sees a promising future for things like concentrated solar and hydrogen in his home state, and thinks different forms of solar thermal, and hydrogen, could go hand-in-hand with offshore wind.
But his ideas come with a caveat. "Onshore wind, direct solar thermal, and geothermal are the three technological investments that the federal government and Department of Energy are working on, and it's all west of the Mississippi,” Leitner described. It would be great if there was more focus put on the indigenous, renewable resources of the southeast, he suggested.*
Though it's clear, he said, that the southeast will never have as much direct radiation or onshore wind as other parts of the country, mainly the southwest and American Midwest, the resources of the southeast should also be a focus of attention.*This interview was conducted prior to President Obama's announcement on Earth Day (April 22nd) stating that the Department of Interior had finalized the long-awaited framework for renewable energy production on the U.S. Outer Continental Shelf. The accouncement was a big boost for offshore wind.
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Nate Blair, Senior Analyst/Group Manager at National Renewable Energy Laboratory in Colorado
Jeffrey Nelson, Manager, Concentrating Solar Power Systems, Sandia National Laboratories
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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