Wind Farms Contribute To Global Warming?

[trymahjong]

An interesting article on research from State University of New York at Albany on Wind Farms having a warming effect on local climates.

Wind Farms May Raise Temperatures

Large wind farms might have a warming effect on the

local climate, research in the US showed on Sunday,

casting a shadow over the long-term sustainability of

wind power.

Carbon dioxide and other greenhouse gases from

burning fossil fuels contribute to global warming, which

could lead to the melting of glaciers, sea level rise, ocean

acidification, crop failure and other devastating effects,

scientists say.

In a move to cut such emissions, many nations are

moving towards cleaner energy sources such as wind

power.

The world’s wind farms last year had the capacity to

produce 238 GW of electricity at any one time. That was

a 21% rise on 2010 and capacity is expected to reach

nearly 500 GW by the end of 2016 as more, and bigger,

farms spring up, according to the Global Wind Energy

Council (OD Feb.7’12).

Researchers at the State University of New York at

Albany analyzed the satellite data of areas around large

wind farms in Texas, where four of the world’s largest

farms are located, over the period 2003 to 2011.

The results, published in the journal Nature Climate

Change, showed a warming trend of up to 0.72° Celsius

per decade in areas over the farms, compared with

nearby regions without the farms.

“We attribute this warming primarily to wind farms,” the

study said. The temperature change could be due to the

effects of the energy expelled by farms and the

movement and turbulence generated by turbine rotors, it

said.

“These changes, if spatially large enough, may have

noticeable impacts on local to regional weather and

climate,” the authors said.

But the researchers said more studies were needed, at

different locations and for longer periods, before any firm

conclusions could be drawn. (Reuters)

[woolie]

So, this is one of the problems with science journalism. The authors present research indicating a small local increase in surface temperatures surrounding a large wind farm. The media picks this up and runs with a story implying that wind turbines contribute to global warming. I am not a climate scientist, but I'm familiar with the pattern of journalists/editors reading a single paper that says something counter-intuitive or against conventional wisdom and writing an attention grabbing headline.

1. Open thermodynamic system. They are sampling a local region; is the temperature change the result of different air mixing, or some other effect? Are the turbines really causing a net increase in temperature, or just changing the distribution. Is it a large net effect, net zero, ...?

2. Life cycle CO2 emissions. What is the total CO2 per MWh life-cycle cost of wind vs. natural gas vs. coal, etc. Even if the turbines somehow managed to cause greater solar energy capture in their immediate area and raise the temperature, would this be offset by much lower CO2 emissions.

3. What does the other literature say on the topic? I went and read some of the author's other papers. One published in PNAS in 2010 suggests that the local air temperature is decreased during the day and increased at night due to air mixing. Another states that a massive roll-out of wind turbines to switch from CO2-intensive electricity sources would have measurable local climate effects, but would be more than offset by the differences in CO2 and thus temperature in the entire system.

4. Do people willfully misinterpreting the paper and making broad sweeping statements beyond the context of the study have an agenda?

Here is the article being discussed if you wish to read it yourselves. While I have institutional subscription access to many journals, I don't have access to Nature Climate Change. I'll see if I can find a PDF of the article on the authors' site.

Zhou, Y. T., Tian, Y., Roy, S. B., Thorncroft, C., Bosart, L. F., & Yu, Y. (2012). Impacts of wind farms on land surface temperature. Nature Climate Change, 2(5)

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1505.html

The wind industry in the United States has experienced a remarkably rapid expansion of capacity in recent years and this fast growth is expected to continue in the future1, 2, 3. While converting wind’s kinetic energy into electricity, wind turbines modify surface–atmosphere exchanges and the transfer of energy, momentum, mass and moisture within the atmosphere4, 5,6. These changes, if spatially large enough, may have noticeable impacts on local to regional weather and climate. Here we present observational evidence for such impacts based on analyses of satellite data for the period of 2003–2011 over a region in west-central Texas, where four of the world’s largest wind farms are located7. Our results show a significant warming trend of up to 0.72 °C per decade, particularly at night-time, over wind farms relative to nearby non-wind-farm regions. We attribute this warming primarily to wind farms as its spatial pattern and magnitude couples very well with the geographic distribution of wind turbines.

[LTAWACS]

Wonderful. Seems that just about anything contributes to global warming. Does anyone now realize that we are in between ice ages?

[kylejack]

Local warming is not global warming.

[Pleak]

Maybe it's all the hot air being expounded on the subject that is causing global warming.

[trymahjong]

I asked one of the climate researchers at Goddard Institute of Space Studies and Climate Research in Manhattan--

she sent me the orginal article and said this. . .

It looks like this is a pretty preliminary analysis. The record they are looking at is very short and noisy. It'll have to be reassessed in a few years! Also, do farmers have different crops or no crops, etc. under the windmills? I don't know.

Interesting though

[kylejack]

Seems to me that they're saying that wind farms create more heat than nothing. But do they create more heat than the various kinds of powerplants, per kwh? That's the more interesting question.