Solar Thermal Power: Not Forgotten


More energy from the sun hits the Earth in one hour than all of the energy consumed by humans in an entire year. According to the Department of Energy, in 2001 the world consumed at an average rate of more than 13 trillion watts ( 13 terawatts, TW), just a fraction of the 120,000 TW of energy available that falls to Earth- free. Life on Earth long ago realized that the sun was the best way to get free energy, just look around at all that green stuff growing outside. Today, solar energy accounts for only 0.1% of our energy portfolio. We will likely look back at the use of fossil fuels as an obvious misstep in technology development. A small blip on the radar of human technology, like a toddler testing the boundaries of what is possible. The Oil Drum's featured guest writer Gerry Wolff, coordinator of TREC-UK, describes a bold plan called DESERTEC that is centered around solar thermal.As the story goes... in 212 BC, Archimedes used a solar thermal concentrator (made up of shiny shields) to focus the suns energy on any Roman ship that dared to sail close to the Syracuse shore. Later tests have confirmed you can set a boat on fire, and I'm sure make the sailors quite uncomfortable in the process.

Today solar thermal concentration is the same idea as burning those Roman ships. Except instead of wooden boats todays concentrators are focused on steam, or sterling engines. Some models have conversion efficiencies above 40%. With such simple construction, and high efficiency, solar thermal is already cheaper than the global price of oil - and prices for solar thermal, are expected to drop dramatically. This, I believe is one of those 'gold rush' moments for clean energy. As befitting a gold rush, some people are dreaming big. Gerry Wolff describes :

"An important part of the DESERTEC concept is the creation of a large-scale HVDC transmission grid, spanning the whole of EUMENA, and designed to work in conjunction with existing HVAC grids. This proposal chimes well with an independent proposal by Airtricity to create a Europe-wide HVDC grid"

While it is true that distributed systems make sense, this writer worries about transmission efficiencies. Wouldn't it make more sense for local grids to be connected, share various power resources, and have high efficiency storage systems? Regardless, I think it is valuable to see where solar thermal can play a more serious role in our energy mix. The majority of life on Earth is already solar powered- why aren't we?
::The Oil Drum