Study: Wind Energy In California Has Few Benefits

June 27, 2013 by  
Filed under Green Energy News

The study “Regional variations in the health, environmental, and climate benefits of wind and solar generation,” published this week in the Proceedings of the National Academy of Sciences (PNAS), charts the relative value of wind and solar energy resources across the United States in relation to the environmental effects of power those resources might conceivably displace. For instance, if wind turbines reduced the need for coal-fired power in a certain region, the reduction in CO2 emissions from the unburned coal would be credited as a benefit to those wiind turbines.

The study also calculated the environmental and social benefit from other pollutants such as nitrogen oxides, sulfur, and particulate matter that accrue from switching to wind and solar power.

The result of the study will likely prrove disheartening for would-be investors in California wind facilities: wind power’s benefits to the state from avoided CO2 emissions are startlingly low compared to regions such as the Great Plains. The authors calculate the combined social and environmental benefit of California wind power from pollution reduction at $13 per megawatt-hour.

The federal government’s Production Tax Credit (PTC) subsidizes qualifying California wind turbines to the tune of $23 per megawatt-hour. Considering that other regions such as Ohio derive up to $100 in benefiits per each megawatt-hour of power generated by local wind, that makes California look like a pretty bad investment for the PTC.

Here are the relevant maps from the study offering the disparity in wind’s benefits at a glance. First, a base map showing raw wind resources:

The Mother Lode for wind power potential is clearly in that big black spotch in the High Plains, but California’s resources aren’t too shabby. But factor in the amount of CO2 emissions avoided by installing wind, and California starts to lose its luster:

There are only a couple places in the state where wind power might potentially displace carbon-fueled electrical power, and those places don’t offer all that much benefit compared to elsewhere in the country. In fact, it looks like if your goal is to avoid CO2 emissions by building wind turbines, California is about the last place you’d want to do so on a cost-effectiveness basis.

When you chart avoided smog-forming pollutants, sulfur, and particulate mattter, California’s benefits from wind seem to vanish altogether:

What’s the reason? The study’s authors say that regional differences in power generation portfolios reduce the benefiits of wind in a few areas, California emphatically included:

Sites in Oklahoma, Texas, and California are less beneficial because gas-fired plants, with relatively low CO2 rates, are predominantly displaced. Because of the relatively clean sources of electricity and the modest wind resource, wind turbines in California are among the least effective at displacing CO2 emissions. A wind turbine at the best site in California displaces 20 percent less CO2 compared with an average site in Ohio.

The lack of benefits from California wind turbines were marked enough that the study’s authors, led by Carnegie-Mellon’s Kyle Siler-Evans, noted the state’s disadvantages in the paper’s abstract, as prominent a mention as a scientific paper can offer:

When wind or solar energy displace conventional generation, the reduction in emissions varies dramatically across the United States. Although the Southwest has the greatest solar resource, a solar panel in New Jersey displaces significantly more sulfur dioxide, nitrogen oxides, and particulate matter than a panel in Arizona, resulting in 15 times more health and environmental benefits. A wind turbine in West Virginia displaces twice as much carbon dioxide as the same turbine in California.

Solar in California fared somewhat better than did wind, at least in benefits from avoided CO2 emissions: each kilowatt of solar generating capacity installed through most of the state displaces around a metric ton of CO2 emissions annually. That said, if you have a kilowatt of solar and you’re choosing where to install it to reduce greenhouse gas pollution most dramatically, you’ll want to skip the Mojave and put that solar in western Kansas, where it will do the climate twice as much good.

The study isn’t perfect. The authors don’t account for power purchases between the larger regional grids shown on the maps above in black outlines. (The outline roughly corresponding to California’s state lines marks the territory of the California Independent System Operator, or CaISO.) California’s utilities have historiically imported a significant amount of coal-fired power from outside CaISO’s turf. Even though that era is slowly drawing to a close, the state imported about 20,800 gigawatt-hours of coal-fired power in 2011, making California’s coal use about four times what in-state generation would suggest, which increases the state’s coal footprint.

But only a bit, in relative terms. California’s coal power comes from the southwestern states, which themselves aren’t particularly worthy for wind development according to the PNAS study. And if we’re criticising the study based on its omission of coal power imported into California, we also have to account for the 30,971 gigawatt hours of gas, hydro, nuclear, and renewable power California also imported in 2011, tweaking the carbon footprint of the state back downward.

Which suggests that even with its omissions, the study may not be far off in casting investment in California wind as investment mainly wasted, at least from an environmental perspective. Given that certain iconic California species are being asked to pay the ultimate price for that investment, it may well be time to do a little rethinking.

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