Solar Two, an “older’ concentrated solar power plant in the Mohave Desert – (replaced by newer technology)
In yesterday’s post I revealed how little I knew about concentrated solar power. In fact I had never heard of it before saw the video clip posted yesterday. Presumably there are more people out there who are like me and are curious about this technology. This wiki link is a comprehensive look at solar thermal energy.
What baffles me is why hasn’t there been more attention to this proven source of renewable, clean energy? Why when we think of solar power don’t we think of solar power plants just as much as we think of panels of photovoltaic cells on rooftops? Concentrated solar power can involve a huge array of hundreds or thousands of mirrors that concentrate the solar rays reflected by mirrors to heat molten salt to 565°C (1050°F). The salt then boils water which drives a steam turbine to generate electricity. There are other ways to do this as well.
Wired has a good article about the huge Solar Plants in the desert. Currrently, there are at least nine solar power plants in the Mojave Desert known as the Solar Energy Generating Systems (SEGS). It uses parabolic trough solar thermal technology along with natural gas to generate electricity. The facility has a total of 400,000 mirrors and covers 1,000 acres. These plants produce 354 MegaWatts, making the system the largest solar plant of any kind in the world.
Solar power from photovoltaic cells is great in that almost anyone who can afford it and who lives in an appropriately sunny climate can install it on their roof and can generate enough electricity to be self-sufficient and potentially give energy back to the grid.
Rooftop solar cells are wonderfully decentralized and doesn’t give all the control of power generation to a select corporate few. But many people, like myself, are unlikely to be in a position to afford solar cells on our roofs, have technical savvy or the time to fuss with it – even if living in the right climate.
So the large scale solar concentrated power centers could be an ideal solution for cheap, clean renewable energy. Although it still may be somewhat expensive compared to cheap fossil fuels, this doesn’t take into consideration of the steep cost we are already paying in terms of the cost we will pay from the harm these greenhouse gas emissions are causing to our environment. Also, as the technology advances and becomes more prevalent the price will come down considerably as well as significant improvements to it’s power and efficiency.
One issue that is critical to making giant concentrated solar power plants is how to transmit this power to other distant parts of the country. Giant power plants in the Southwest desert sounds great but how would you get the power to New York City or Atlanta?
The TREC website (Trans-Mediterranean Renewable Energy Cooperation) says “Every year, each square kilometre of hot desert receives solar energy equivalent to 1.5 million barrels of oil. Multiplying by the area of deserts world-wide, this is nearly a thousand times the entire current energy consumption of the world.” They go on to talk about their initiative to promote modern high-voltage DC transmission lines in a super grid that could supply areas from not only solar power plants but also wind powered generators and the like. More info on their site here.
Many thanks to Gerry Wolff for his comment yesterday which lead me to find out a little more about this issue. Here is a link to a very good pdf he wrote, an overview of concentrated solar power with some excellent photos.
Here is another good article by the National Renewable Energy Laboratory (NREL) about how NREL Research Helps Deliver Clean, Solar Electricity to Thousands of Homes in the Southwest.