A team of engineers have discovered a new way in which to harness energy from the ocean. The team have been able to harness the energy by playing with three factors of the oceans water, namely: the difference between warm surface water and cold deep water. They will be using these factors to produce electricity.
The process known as OTEC stands for Ocean Thermal Energy Conversion. This process could change the face of energy supplying technology for much of the world’s tropical coastlines and islands.
After a decade of work, tech firm Makai Ocean Engineering is beginning to supply the grid with power from OTEC in a small research facility in Kona on the big Island of Hawaii.
The plant that’s situated in Kona is rather small, it produces only 105 kilowatts of power which is enough to power 120 homes. The energy produced from the plant will be sold to the local community.
“There’s a huge amount of energy stored in the ocean’s surface,” Hartman told media reports. “The estimates are greater than the total energy needs for the planet. The tricky part is how you harness it.”
The Makai OTEC plants draws out the energy by pulling the warm water from the surface of the ocean which in turn warms the outside of a container of ammonia. This then vaporizes due to its low boiling point. The vapour from the ammonia then drives a turbine to produce the electricity. The ammonia vapour, traveling through a pipe, is condensed and turned back into liquid when the pipe passes through cold water that has been drawn up from an ocean depth of 3,000 feet. The cycle is repeated. The temperature difference in the water needs to be at least 20 degrees Celsius.
Many island communities are well situated to take advantage of the thermodynamics of heat exchange using the difference in cold and warm water.