Thursday, April 29, 2010

Energy from All Around Us

It's somewhat ironic that the long-awaited approval of the Cape Wind offshore wind project by the Department of Interior (DOI) should come in the same week that the nation's attention is focused on the problems of another, more traditional offshore energy project. Although the renewable electricity from the former scarcely substitutes for petroleum from the latter, Cape Wind is nevertheless emblematic of an intentional shift from energy sourced far away, in places like the deepwater Gulf of Mexico, to energy derived from sources all around us. If Secretary Salazar had turned it down, it would have cast serious doubts on the administration's entire clean energy agenda. However, concurrence with this one project doesn't answer all questions concerning the larger shift, of which it represents just a small component. Similar issues are bound to come up with increasing frequency as the transition to new energy continues.

Cape Wind and the Macondo prospect that the Deepwater Horizon rig was drilling into represent opposite poles of the energy spectrum, and not just because the latter is now leaking oil into the marine environment at a rate that the latest estimate puts at 5,000 barrels per day, much higher than initially thought. Cape Wind would tap into the clean and renewable, but extremely diffuse energy sources that surround us. After taking into account the restrictions imposed by DOI, its 130 turbines would on average generate as much electricity as a gas turbine power plant consuming a quantity of natural gas equivalent to 6,000 bbls/day of oil. In other words, it takes a very large array of offshore wind turbines to match the energy in the oil currently leaking from a single well. Platforms similar to what BP might have been planning to install after successfully completing the exploration of Macondo routinely produce up to 20 times that much oil.

The implications of this huge difference in energy density are clear. Without the energy concentration that nature has embedded in fossil fuels over many millennia, the hardware required to tap natural energy flows in real time becomes vast in extent. Generating 20% of US electricity needs from wind, which some see as just the beginning, will ultimately require more than 8 times as much wind capacity as the 35,000 MW installed as of the end of last year, even if US electricity demand remains static in the interim. Solar power, which last year generated just 0.02% of our electricity, would have to increase by a much larger factor. This is one of many reasons that increased reliance on nuclear power is such an important element of the transition to more sustainable energy sources, because nuclear--and to a lesser extent geothermal power--represents a critical source of highly-concentrated, low-emission energy. The more nuclear in the mix, replacing baseload coal, the less we must rely on distributed energy gathered in our immediate vicinity.

In any case, in order to obtain a much larger portion of our energy diet from sources like onshore and offshore wind and solar power, projects like Cape Wind must go from being rarities to ubiquitous features of our seascapes and landscapes. The opposition to Cape Wind that has delayed this project for years is focused on a central dilemma of that shift: Many of the same underlying trends that lead us to want to harness clean energy from wind, sunlight and geothermal heat have also increased our focus on the broadly-defined environmental impacts of doing so.

Our grandparents wouldn't have blinked at putting up tens of thousands of wind turbines, let alone the few hundred slated for Nantucket Sound. They'd have thought of them as signs of progress, just as they viewed oil derricks and power lines. It's incumbent on us to balance our more modern sensibilities related to the "viewscape" with fundamental environmental challenges of climate change and sustainability, as well as the need to sustain the energy supplies our civilization requires. Approving Cape Wind--whether it eventually gets built or not--is entirely consistent with those imperatives.

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