Ocean Thermal Energy Conversion doesn’t get much notice. However, especially for islands, it is a reliable way to generate renewable energy 24/7. OTEC creates electricity by using the difference in temperature between cold water at lower depths and warm water at the top, and can generate prodigious amounts of power. Makai Ocean Engineering says all of Hawaii’s power could be generated by 12 commercial-scale OTEC plants.
OTEC pumps in cold water from the depths and warm water from the top. The warm water is used to heat ammonia, converting it to a gas to power turbines. The cold water cools the ammonia back into a liquid so it can be used again. The ammonia is stored in a closed system. Ocean water never mixes with ammonia. Mixed temperature water is pumped back into the ocean at a depth where water is a similar temperature.
OTEC News reports on developments and new installations.