Showing posts with label solar hot water. Show all posts
Showing posts with label solar hot water. Show all posts

Wednesday, July 22, 2009

A Sunny New Market for Clean Power: The Caribbean

Note: Low-tech Applications such as solar hot water batch heater have huge market in the Caribbean.

Written by Jennifer Kho

carribbeangeneric1Last year’s oil spike feels like a distant memory, but to remind you, oil prices surpassed $147 per barrel last July, with gasoline prices above $4 per gallon. But if you think that was bad, feel lucky you weren’t living in the Caribbean at the time.

Yes, I said “lucky.” Because while living in the Caribbean islands may have plenty of other perks, the islanders suffer more than Americans when oil prices skyrocket. After all, the United States gets only 2 percent of its electricity from petroleum, with most of its electricity coming from coal and natural gas, according to the Energy Information Administration. Meanwhile, a whopping 92 percent of the electricity in the Caribbean comes from oil, said Babul Patel, a senior consultant for energy software and consulting firm Nexant Inc., at the Intersolar North America conference in San Francisco last week.

As a result, the region suffered “a major shock” last year, which sparked interest in renewable energy in the last six to eight months, and caused the region to realize “reliance on only one [energy source] is not a viable option,” Patel said. That awareness has led to research initiatives, as well as initiatives to develop certification programs for solar-water-heater manufacturers, establish a renewable-energy center and create renewable-energy policies.

Solar power in the region has a strong potential for agricultural applications, such as for crop dryers and water pumps for irrigation, as well as in some industrial applications. The islands also have plenty of hydro, geothermal and wind resources, and geothermal resources are particularly plentiful on Nevis, Saba and Dominica; Dominica and the southern islands have the most hydro potential, while most of the islands have good wind and solar resources.

But renewables face some barriers to reaching the Caribbean market, not least of which is cost. And the islands’ remote isolation doesn’t help. Large hydro and geothermal projects are cost-effective because they can produce large amounts of electricity cheaply, but don’t work out as economically on a smaller scale, Patel said. Meanwhile, individual islands don’t use enough electricity to justify larger projects, and aren’t able to export it at this point. Exporting electricity would require extensive – and expensive – undersea power cables, as well as power-sharing agreements among the islands.

In addition, most of the islands are small, meaning that little land is available for wind and solar farms, Patel said, calling large utility-scale solar projects “unfeasible.” And offshore wind is unlikely to be allowed because of tourism and fishing concerns, he added.

Wind’s intermittency is another concern. Because the wind doesn’t always blow when it’s needed, increased wind capacity wouldn’t decrease the amount of diesel capacity the islands would need to keep on hand for calm times, Patel said. That reliance on diesel is what the islands hope to avoid by diversifying into renewables in the first place.

Finally, hurricanes could complicate matters. Patel said that wind-turbine and solar-panels in the area need to be designed to be more robust against hurricanes, and this could help make renewable-energy projects more viable in the region.

Better policies also could boost renewables. While some islands have set goals, and a few – including Martinique and Barbados – have solar incentives, most are sorely lacking in programs that could attract private investment, Patel said. He recommended that the islands divert some investments from petroleum-based energy and partner with utilities if they want to meet their energy-security goals.

Caribbean leaders might consider looking at some of Hawaii’s initiatives. While some the conditions are clearly different, Hawaii — like the Caribbean — gets much of its electricity from oil, and the state has become one of the most aggressive pursuers of renewable energy, setting a goal of reaching 40 percent of its power from renewables by 2030.

Monday, March 16, 2009

Photovoltaic Mileage

New Life-Cycle Assessment Reveals Your Photovoltaic Mileage May Vary

by Jeremy Elton Jacquot, Los Angeles on 02. 9.08
Science & Technology

Not all photovoltaic technologies are created equal; some, in fact, incur quite heavy environmental footprints - producing silicon, for example, consumes a lot of water and energy while refining zinc produces a sizeable chunk of emissions. Environmental Science & Technology's Naomi Lubick reports that Vasilis Fthenakis, a scientist at Columbia University and the Brookhaven National Laboratory, just finished a LCA of some of the leading technologies which determined that new thin-film cadmium-telluride (CdTe) materials - such as the ones we covered here - come out on top.

Benefiting from its highly efficient energy conversion, CdTe photovoltaic systems consumed less energy and produced fewer emissions; in addition, when compared to its multicrystal and ribbon silicon competitors, the CdTe technology had the lowest cost. In order to obtain these results, Fthenakis and his colleagues compared data from more than a dozen solar companies, taking into account the manufacturing process, energy conversion and various components.

Unfortunately, the assessment failed to shed light on the technologies' total environmental impact - "not telling you exactly what your impact is if you were to buy them," as Corinne Reich-Weiser, a graduate student at UC Berkeley, explaine

d. For instance, she notes that the emissions produced during the transportation of components before production and assembly are only partly taken into consideration; moreover, the assessment is based on idealized European and U.S. grids even though most components are built in China.

Still, it provides an effective means of "easily comparing" all of the available technologies, she says, deeming it "incredibly useful." New and future solar technologies should be able to bridge that emissions gap within the coming years as companies continue innovating and expanding their operations. Fthenakis notes that the one missing element from his assessment he hopes to amend soon is the end-of-life and recycling data; he believes this should help make the technologies' emissions profiles even better.