Peter visited the Acciona Solar Power Plant just outside Boulder City, Nevada, during a visit to the United States in July 2007.

The 64 Megawatt solar array covers 300 acres and began generating power for Las Vegas in July.

The solar thermal plant uses the sun's energy to heat oil, which in turn is used to create steam to drive a conventional turbine generator.

The array of parabolic mirrors track the sun throughout the day and focus energy onto the tube of oil running along the centre of the mirrors.

Peter also visited the Indian Point Nuclear Power Plant on the banks of the Hudson River in New York. The power station operated by Entergy Nuclear Northeast produces 1,000 Megawatts from each of two units.