The Pew Charitable Trust issued a report on Clean Energy which has some interesting figures. While the US was third in 2010 after China and Germany in investment in renewables at $34 billion and second to China in total renewable generation capacity at 58 gigawatts (China has 103 gigawatts), the really interesting number is the Clean Energy investment per $ of GDP. According to Pew, the top four countries are:
1. Germany at 1.4%
2. Italy at 0.79%
3. China at 0.55%
4. Canada at 0.42%
The US investment in Clean Energy per $ of GDP is 0.23%, below most of Europe.
What if the US aggressively pursued renewables? Would it make a big difference?
The US generated 4 trillion kilowatt-hours (4000 TWh) in 2009. This is equivalent to 36.5 kilowatt-hours per day per person. According to David MacKay, a Cambridge University Physics Professor, in his book Sustainable Energy -- without the hot air:
"A study by Elliott et al. (1991) assessed the wind energy potential of the USA. The windiest spots are in North Dakota, Wyoming, and Montana. They reckoned that, over the whole country, 435 000 km2 of windy land could be exploited without raising too many hackles, and that the electricity generated would be 4600 TWh per year, which is 42 kWh per day per person if shared between 300 million people."
inference.phy.cam.ac.uk
But suppose we don't want to rely so heavily on Wind Power. Would Solar Thermal (as opposed to Solar Photovoltaic) be able to make a meaningful contribution?
To give an idea of the potential of Solar Thermal, Professor MacKay provides the following illustration:
inference.phy.cam.ac.uk
(The 250 kWh/d figure is arrived at assuming the energy provided by oil, natural gas for heating, etc are substituted by electricity).
It should be noted Solar Thermal can use air cooling instead of water cooling to condense the steam generated by the solar arrays. This is the technique used by the Ivanpah Solar Plant, located in the Mojave Desert. |
