Eighty percent of the sun’s solar energy is absorbed into the surface of the world’s oceans, and it is replenished daily regardless of weather patterns. In a closed-cycle OTEC system, water flows through a large pipe and heat exchanger, which heats a liquid with a low boiling point, such as ammonia. As the boiling ammonia creates steam, it turns a turbine generator to produce electricity. A second pipe extracts cool deep water from the ocean, which condenses the steam back to liquid form. As the ammonia is recycled, the process repeats, creating unlimited clean energy 24 hours a day, 365 days a year.

This process, known as the ‘Rankine Cycle’, is commonly found in oil, coal and nuclear power generation plants. The distinguishing difference with OTEC, is that it also employs the solar energy from the ocean. No fossil fuels are used in OTEC’s power generation. The science behind the conversion was conceived in the 1880s, although the first net power-producing facility wasn’t developed until the 1990s. Located in Hawaii, USA at the Natural Energy Laboratory of the Hawaii Authority (NELHA), the plant was funded by the US Department of Energy.

Today, this demonstration OTEC plant is the world’s first net power-producing facility connected to the US grid. Technological advances in deep water piping have made large-scale pipes commercially available for OTEC plants as outlined in this 2009 NOAA report. This development, in conjunction with volatile oil prices and global renewable energy mandates, makes this an opportune time to advance OTEC into the market. It’s an important science that deserves your every attention and investment.

Click the graphic for a virtual demonstration