Renewable energy could wreck the environment, according to a study that examined how much land it would take to generate the renewable resources that would make a difference in the global energy system.
Building enough wind farms, damming adequate number of rivers and growing sufficient biomass to produce ample kilowatts to make a difference in meeting global energy demands would involve a huge invasion of nature, according to Jesse Ausubel, a researcher at the Rockefeller University in New York.
Ausubel came to this conclusion by calculating the amount of energy that each renewable source can produce in terms of area of land disturbed.
“We looked at the different major alternatives for renewable energies and we measured [the power output] for each of them and how much land it will rape,” Ausubel told LiveScience.
Land grab for energy
The results, published in the current issue of International Journal of Nuclear Governance, Economy and Ecology, paint a grim picture for the environment. For example, according to the study, in order to meet the 2005 electricity demand for the United States, an area the size of Texas would need to be covered with wind structures running round the clock to extract, store and transport the energy.
New York City would require the entire area of Connecticut to become a wind farm to fully power all its electrical equipment and gadgets.
You can convert every kilowatt generated directly into land area disturbed, Ausubel said. “The biomass or wind will produce one or two watts per square meter. So every watt or kilowatt you want for light bulbs in your house can be translated into your hand reaching out into nature taking land.”
Small dent in landmass
Other scientists are not on board with Ausubel’s analysis and say that his use of energy density—the amount of energy produced per each area of land—as the only metric may not be the correct way to calculate the impact of energy from renewable resources on the environment.
“In general, I would say his use of energy density just does not capture the entire scope of issues and capabilities for all the different resources,” said John A. Turner, a principal scientist at the U.S. National Renewable Energy Laboratory, who was not involved in the study.
Turner explains that if the entire United States were to be powered by solar cells with 10 percent efficiency, an area about 10,000 square miles would have to be covered by solar panels in a sunny place such as Arizona or Nevada.
“Now there’s 3.7 million square miles of area for the continental U.S.” Turner told LiveScience. “This represents a very, very tiny area. And that’s just one technology.”
“If you look at how much land area we’ve covered with roads, it’s more than double that. So yeah, it’s a large area, 100 miles by 100 miles, if you pack it into one thing, but if you scatter it across the country and compare it to all the other things we’ve already covered, it’s not an egregious area.”
Double use of land
Ausubel’s analysis concludes that other renewable sources such as solar power and biomass are “un-green”. According to his findings, to obtain power for a large proportion of the country from biomass would require 965 square miles of prime Iowa land. A photovoltaic solar cell plant would require painting black about 58 square miles, plus land for storage and retrieval to equal a 1,000-megawatt electric nuclear plant, a more environmentally friendly choice, Ausubel wrote.
However, new land doesn’t have to be put into use just for a solar plant. Some scientists say already existing infrastructures could be doubled up for use to cover such an area.
“We could do with just rooftops of buildings and homes, land area we’ve already covered,” Turner said. “We could meet 25 percent of our annual electrical demand by just putting solar panels on already existing rooftops of homes and businesses.”
“Similarly, wind farms use up a lot of land area but they only really take up 5 percent of the land they cover,” he explained. “The rest of it can be used for farming so it doesn’t really impact the land area that much.”
Ausubel thinks that a better alternative to renewable energy resources would be nuclear power, which would leave behind far less waste than other alternatives
“There are three legs to the stool of environmentally sound energy policy—one is improved efficiency, second is increased reliance on natural gas with carbon capture and sequestration and the third is nuclear power,” he explained.
“Nuclear power has the proliferation issues, which are serious but the environmental issues are small. With nuclear energy the issue is to contain radioactivity, which has been successfully done.”
Turner agrees that nuclear power leaves a smaller carbon footprint, but he thinks that the waste issue associated with this technology is very serious.
“It’s unconscionable to dismiss the issue of nuclear waste," Turner said, “because you have to store that waste for hundreds of thousands of years and nuclear wastes are particularly damaging to the environment and have social impacts also.”
Similarly, Gregory A. Keoleian, co-Director for the Center for Sustainable Systems at the University of Michigan, thinks more in-depth analyses are needed before dismissing renewables and considering nuclear power as a viable option.
“I think the characterizations made that ‘renewables are not green’ and ‘nuclear is green’ sound provocative, but they do not accurately represent these technologies with respect to a comprehensive set of sustainability criteria and analysis,” Keoleian told LiveScience. “The treatment of renewable technologies [in this study] is shallow and the coverage of the nuclear fuel cycle is incomplete."
To capture the entire scope of issues and capabilities for all the different resources, scientists believe there need to be more studies and discussions.
“We have a finite amount of time, a finite amount of money and a finite amount of energy, and we need to be very careful about the choices we make as we build this new energy infrastructure,” Turner said. “I’d like to see something that will last for millennia and certainly solar, wind and biomass will last as long as the sun shines. “
- Top 10 Emerging Environmental Technologies
- Power of the Future: 10 Ways to Run the 21st Century
- Quiz: What's Your Environmental Footprint?