Location May Stymie Wind and Solar Power Benefits

Wind farms and solar installations are often located in places where they will have the least impact on climate and health, a report finds.

These renewable energies emit less carbon dioxide and air pollution than burning fossil fuels for electricity. But the windiest and sunniest places in the United States — such as the southwestern plains and deserts — are not always the most socially and environmentally beneficial sites for wind turbines and solar panels. The benefits, according to a study published today in Proceedings of the National Academy of Sciences, vary depending on what energy sources are being replaced.


New wind and solar installations displace the most carbon dioxide and air pollutants where they replace the coal-fired plants found predominantly in eastern and Midwestern states such as Indiana and Pennsylvania. The benefits are much smaller in California and the US southwest, where cleaner gas-fired plants are more common.

“One would think it makes most sense to install the next solar panel in sunny California, because the solar resource is better there,” says InĂªs Lima Azevedo, an environmental engineer at Carnegie Mellon University in Pittsburgh, Pennsylvania, and a co-author of the study.


“But if we start thinking about the emissions that are displaced by adding that solar panel, the story is different: in Pennsylvania, one will be displacing old and dirty coal power plants and thus avoiding more health and environmental damages associated with the emissions from those plants.”


The team calculated the power-generation capacity of thousands of wind turbines and hundreds of solar panels across the United States and evaluated the corresponding health and environmental benefits. Assuming a social cost to the environment and human health of US$20 per ton of carbon dioxide emitted, and $6 million per air-pollution-caused death, the combined climate and health benefits per megawatt hour used from electricity produced by solar power range from about  $10 in Arizona, to $100, in some northeastern states, the researchers estimate.


Social benefits
 
As for wind energy, the overall health and environmental benefits in the United States amount to $2.6 billion per year. This is 60% more than the yearly US subsidy of $1.6 billion for wind power diffusion, the researchers say. But the US production tax credit — the main policy mechanism to induce wind-power development — encourages investors to seek sites with the highest energy output rather than those with high social benefits, says Lima Azevedo.


As a result, 30% of the 34,000 megawatts of wind capacity in the United States is installed in Texas and California, where social benefits are lowest, and less than 5% is in Indiana, Ohio and West Virginia, where wind power offers the greatest benefit from displaced pollution.


To maximize benefits for taxpayers, Lima Azevedo says, policy-makers should think about a subsidy scheme that encourages operators to build plants where they will yield the biggest health and climate gains. The easiest way to do that, she says, would be to price air-pollutant emissions at their source — the power plants.


The findings are “exceedingly interesting” and relevant for any nation weighing the costs and benefits of moving towards more wind and solar energy, says Nebojsa Nakicenovic, an energy-systems analyst at the International Institute of Applied System Analysis in Laxenburg, Austria. “This study clearly shows that, if installation sites are well chosen, the costs that some may feel worried about are in fact more than offset by avoided damages to human health and the environment.”


The future of PV has just begun



JA Solar’s CEO Peng Fang supports the goal of 300 GW/a globally by 2025. PV magazine talked to Fang in Singapore about his views about the bright future for photovoltaics.

At  your opening  speech of the Financial Summit of APVIA recently in Singapore you talked in a very positive way  about the future for photovoltaics. Why are you so optimistic? 

The future for photovoltaics is very bright. If you look how the solar industry started and how it  developed within the last 5-7 years and how photovoltaics became already an import part of our energy mix, it is amazing. Through the steep cost cuts, PV is almost competitive and we are on the verge of  grid parity in many parts of the world. In many countries like China or the  Southeast Asian region, we see a growing energy demand and nobody can deny that solar energy will play a crucial role to meet this. Wehave  brought down the cost of photovoltaics from US$5 to $1.20 per Watt within a few years, this is a dramatic change.


How do you see the Chinese domestic market?

Last year we saw already over 2 GW of new installations, this year we expect already over 5 GW. Until 2020 I see around 100 GW installed total PV capacity in China is possible; one hundred times as much as today. We increased our Chinese sales from much less than 100 MW last year to 300 MW this year.


What about conventional energy like coal?

Already nowadays 60% of the Chinese railway  system carries coal transports. If this dependency on coal won`t change in the future, the whole system will be non sustainable, besides the environmental aspects. Also in other countries we see this discussion and a change towards a more sustainable energy future.


But in many countries like Germany and the U.S. there is now a pretty controversial debate about the costs and efficiency of PV, for example about its intermittency or the problems of grid integration. What's your take on this?

I just came back from Germany and had visited Bad Staffelstein, a small town. There they have already a share of solar electricity of over 30 percent at the local electricity mix. And they don`t have technical problems. In China we would expect a share of solar electricity of about 10% at the electricity mix in next couple of decades, so this should also be possible without technical problems.


In neighboring countries like India or the Philippines we see massive power shortcuts and blackouts due to the rising energy demand and an inefficient production and distribution system. How about the situation in China?

China’s economy booms and in the summer of 2010 we saw, for example, in the West massive energy shortages. Many manufacturing plants had to be temporarily shut down and they had to use Diesel powered generator back up systems to run the production, with a cost of around US$0.33 cents/kWh. Solar electricity is half the price!


So in several countries we see growing PV rooftop installations on manufacturing sites, is this also a trend in China?

Yes, the government just launched a new program for solar distributed power, which will bring a big push for commercial rooftop applications together with further declining prices.


Do you have PV installations on your own facilities? Do you use solar backup systems?

We don't use solar back up systems yet, but we have several MW installed PV on some of our manufacturing sites. But not all of our rooftops are suitable for PV installations. In some of our new facilities, where we plan PV installations from the beginning, this will be easier.


Back again to the growth perspectives of the PV market in China and the government policy. Do you see a great openness for more installed PV, also under a new government next year?

So far the goals for PV installations have been enlarged with every new 5-year plan and I am very optimistic that this will continue. The first step was 18 GW by 2020, now the goal is already 50 GW by 2020. We from the industry suggested 100 GW, but some government officials already went further and suggested 150 GW. So the government is even driving the industry! By now the goal for PV is a one percent share of the electricity mix by 2020, but I am sure, this will be enlarged.


We from pv magazine claim 300 GW/a PV by 2025 can be achieved globally. This is a step to 100% renewable electricity mix by the year 2050 or before, where we will see about 10,000 to 12,000 GW totally installed PV. Do you think this is realistic?

Yes, this is achievable and necessary. The future of PV has just begun and we need a sustainable energy future.