Here's a report at Discovery.com of a study suggesting that earth's available wind resources are more than adequate to supply all of our future electricity needs, with plenty left over. While reassuring, I'm not sure this fact will surprise anyone. Although our energy use has grown large enough to have a noticeable impact on the planet's environmental systems--this is what man-made climate change is all about--we are still pikers relative to the natural forces of sun, wind, or the heat welling up from the earth's core. Unfortunately, even for a well-developed technology such as wind power, tapping it depends on a lot more than simple availability of the energy flow. The comment from an environmentalist suggesting that the biggest impediment that wind power faces is the "fossil fuel habit" of utilities is thus a remarkable trivialization of what's entailed.
At the moment, wind is the most promising of the alternative energy technologies for electric power generation. In fact, it's almost at the point of being competitive with conventional alternatives without subsidies. This still leaves three significant obstacles to deployment on a wide enough scale to be considered a replacement for large, central power plants:
- Intermittent power. Even the best wind resources, those that blow reliably year round, still exhibit significant variations. That means that a standalone wind power grid would have to be built with a much higher nameplate capacity than necessary to meet demand, and will require either backup power or power storage. The combination of these factors quickly renders wind uncompetitive. This says that wind cannot grow its share in any distribution grid beyond the capacity of the grid to accommodate its intermittent supply.
- Environmental opposition. We've already seen a number of instances of organized opposition to major wind projects, by groups that might otherwise have been thought to favor clean energy. The Cape Wind project near Nantucket is only one example of this. Until environmental groups decide whether wind is a sufficient improvement over fossil or nuclear power to be willing to concur with its implementation in all but the most environmentally sensitive areas--and by this I don't mean those with the highest real estate values--then wind will remain a niche power source and fail to reach even the practical limits set by grid acceptance.
- Investment capital. Building all these wind farms will require lots of capital, but then so will generating the same electricity by conventional means. In order to succeed, wind needs to offer the same kind of returns as other options, or else be limited to that pool of investors willing to accept lower returns in recognition of its environmental benefits. Most of the environmentally-focused investors I've met expect returns comparable to other investments.
Knowing there's enough wind, with enough of it in the right places, is an important consideration in promoting the further expansion of wind power. Unfortunately, it's one of those classic necessary, but not sufficient conditions.