Sunday, 14 December 2008

Comparing renewable energies – Mark Jacobson

Stanford civil and environmental engineering professor Mark Jacobson proves that the options touted by coal and ethanol lobbies and the media, are 25 to 1,000 times more polluting than the best renewables. Full text of his paper in Energy and Environmental Science; video interview, PDF of his slideshow. Photo: Stanford News
Sources of electric power, best choices to worst:
  1. wind power
  2. concentrated solar power (CSP)
  3. geothermal power
  4. tidal power
  5. solar photovoltaics (PV)
  6. wave power
  7. hydroelectric power
  8. equally bad: nuclear power, and coal with carbon capture and sequestration (CCS)
For transport vehicles, the same results are followed by ethanol as the worst choices:
9. corn-E85
10. cellulosic-E85
Jacobson's is the first quantitative, scientific comparison of US energy sources to compare their impacts on global warming, human health, energy security, water supply, space requirements, wildlife, water pollution, reliability and sustainability. It received no funding from any interest group, company or government agency.

When energy options for all of these impacts are considered, wind is by far the most promising, with over 99% reduction in carbon and air pollution; it would need less than 3 square kilometers of land for the turbines to run the entire U.S. fleet (if BEV: battery-electric vehicles); saving thousands from premature air-pollution-related deaths; and virtually no water consumption.
Land between turbines on wind farms would be simultaneously available as farmland or pasture or could be left as open space. A BEV fleet would require 73,000 to 144,000 5-megawatt wind turbines, fewer than the 300,000 airplanes the U.S. produced during World War II and far easier to build. By contrast, corn ethanol will continue to cause more than 15,000 air pollution-related deaths in the country every year, and take 15% of agricultural land. Cellulosic ethanol is even worse than corn ethanol because it results in more air pollution, requires more land to produce and causes more damage to wildlife.

Current US energy subsidies throw money away on the wrong options, he says. “Biofuels are the most damaging choice we could make. Recent research shows they not only produce more CO2 ... [but] actually cause more harm to human health, wildlife, water supply and land use than current fossil fuels."

So-called "clean coal" is not clean at all, he says. "Coal with CCS emits 60 to 110 times more carbon and air pollution than wind energy.” It has no effect on pollution due to mining or transport of the coal, and requires about 25 percent more coal, increasing mountaintop removal, water and air pollution. Coal and nuclear energy plants take much longer to plan, permit and construct; adding years of emissions from outmoded "dirty" plants while waiting for the new energy sources to come online.

Nuclear emits about 25 times more carbon and air pollution than wind energy. It has other risks. "Once you have a nuclear energy facility, it's straightforward to start refining uranium,” as Iran is doing and Venezuela is planning to do. "The potential for terrorists to obtain a nuclear weapon or for states to develop nuclear weapons that could be used in limited regional wars will certainly increase.” He calculates that deaths from one terrorist nuke in a small city would be double the deaths from current vehicle air pollution over 30 years in the entire USA.

Though some call his highest-ranked renewables variable and therefore unreliable, previous studies by his research group showed that a national energy grid coordinating output from different locations would overcome variability and deliver a steady supply of baseline power to users.

He says, "There is a lot of talk among politicians that we need a massive jobs program to pull the economy out of the current recession. Well, putting people to work building wind turbines, solar plants, geothermal plants, electric vehicles and transmission lines would not only create jobs but would also reduce costs due to health care, crop damage and climate damage from current vehicle and electric power pollution, as well as provide the world with a truly unlimited supply of clean power."

See also Amory Lovins, The Negawatt Revolution (1989), Wikipedia on negawatt power, load management, renewable energy; summary of 22 Oct 08 Deutsche Bank study Investing in Climate Change 2009.

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