Themis Solar Power Tower: Vintage Photovoltaics!

Construction of the Themis solar power tower was begun in 1979, around the same time that the US was beginning to exploit the Alaskan oil reserves.When completed and put into operation, it had a power output of roughly 2 MW. It cost the French government 300 million francs (about 45 million Euros) and presented an impressive array of 201 mirrors positioned to direct the Sun's heat to drive huge boilers. A boiler is simply a container filled with water and lined with cooling tubes.

These mirrors were seated on a tower that was 100 meters high. The thermal energy that was produced was carried by molten salts (potassium nitrate, sodium nitrate and sodium nitrite) into a vaporizing generator and resulted in the creation of usable electricity to power a turbine. The vapors were rated at 430 degrees Celsius - that's hot!

The coolant proved to be quite difficult to manage and the feasibility of the project was questioned. After three short, experimental years, the project was shut down. For the next 20 years, the Themis solar power tower stagnated - serving no further purposes besides acting as an occasional scientific research facility.

Today, the Themis solar power tower has undergone a massive rehabilitation. Many of the mirrors were replaced with solar panels and the entire structure is now back in action. The power tower is still working, still being used as an active research tool, for the development and implementation of photovoltaic energy provision.

If the other governments of the planet would have demonstrated the commitment to alternative energy provision as did the French in the 70s, maybe we wouldn't have so many of the problems that we do today.

The solar power tower: a vintage lesson in green technology!