[There are multiple nuclear-related issues in the news this week. While the announced closure of Vermont Yankee has been getting the most attention from the nuclear community in the past few days, there is at least one other issue that is timely, so I will turn my attention this week to the news from 3,000 miles away.]
Even as the flames around Rim Fire at Yosemite still blaze, we learn that they are bringing to light yet another concern about our energy supply--the potential susceptibility to wildfires. A recent editorial in the Wall Street Times referred to the new "message" we are seeing from the inferno as "California's Smoke Signals." (Note: The WSJ is a subscription publication. As of the date of this writing, the editorial was available via an Internet search on the title, but I can't vouch for its permanence. However, I will cover the key points below.)
There seem to be two parts of the problem: siting of facilities and transmission lines. The WSJ puts most of its emphasis on transmission lines, but I will start with the siting problem.
The WSJ notes that most solar and wind projects are located in fire-prone areas--dry, sunny desert and valley regions in the case of large-scale solar plants (at least in California), and mountainous regions in the case of wind farms. Both of these types of areas are inherently vulnerable to fires, and although the editorial doesn't say so, climatic changes could exacerbate the vulnerability of these areas in future years.
Other kinds of power facilities, such as nuclear and coal plants, tend to be sited along the coast or on large bodies of water. While it is not impossible for them to be affected by an external fire, the probability of them being exposed to large, long-duration blazes is much lower.
The other, more general, problem is that of transmission lines. In this case, ANY power plant that is sited far from populated areas requires miles of transmission lines, often through--you guessed it--fire-prone areas. Thus, large-scale solar and wind power stations are doubly vulnerable--they can be shut down by fires either at their sites or anywhere along their transmission lines.
However, nuclear plants, hydropower plants, or large coal-fired plants that are sited far from population centers have the same vulnerability to the transmission problem. Hydroelectric power plants obviously have to be sited at suitable bodies of water. Large-scale solar and wind projects require places where large tracts of land are available. Large nuclear plants need access to water. Even if cooling towers are used, public concerns will prevent them from being sited near population centers (although nuclear plants, with or without cooling towers, can be sited a lot closer to population centers than the 120-mile and 150-mile transmission lines mentioned in the editorial).
The editorial cites a 2008 draft Environmental Impact Report for the San Diego Gas and Electric area that indicated there had been 33 "reported power outages" from 16 different wildfire or lightning events occurring from 1986 to 2005. While this is less than one causal event and less than two outages per year, these types of outages, occurring in remote areas and sometimes over a widespread area, are generally not fixed quickly. (No data was reported in the editorial on lengths of these outages, number of people affected, or costs of repairs.)
Although the WSJ paints this vulnerability as a problem of the "green political obsessions" of California, I see the issue as more complex.
The description of the problem leads me to think that more attention needs to be given to citing some fraction of our energy supply closer to population centers, especially in areas of the country prone to large-scale fires. This can be done--to some extent--with almost every power source (except perhaps hydropower). There are certainly smaller-scale applications of solar and wind energy. There are also small, more passive, nuclear reactors under development that should be able to be sited closer to population centers.
These statements are, of course, easy to make but hard to implement. The reactors are still under development. There is still a NIMBY problem, both for nuclear plants and, increasingly, for windmills. There is still the reliability problem for renewable energy sources. (This is true regardless of scale, but the larger-scale projects often are combined with on-site storage systems.) There is the cost of the loss of economies of scale. Alternatively, there might be a possibility of rerouting some transmission lines to make them less vulnerable to fires, but that will also entail a substantial cost.
The point is that the wildfires are a graphic argument for diversity of supply. I have always believed that diversity is important, but I must admit that, until this week, I thought of it primarily as an issue of mixing sources, such as nuclear, coal, gas, and renewables. Now, however, I think the definition needs to be expanded to include diversity of size and location as well.