News
Power generation by Ocean Thermal Energy Conversion Kumejima, Okinawa considering experiment for development
The Ryukyu Shimpo, October 1, 2011
[Brief translation]
Okinawa Prefecture is considering a demonstration experiment to seek possibility of "Ocean Thermal Energy Conversion (OTEC)" at the surrounding sea of Kume Island (or "Kumejima") as new energy policy from the next fiscal year onward. Town of Kumejima conducted research using Okinawa Prefectural Deep Sea Water Research Center (Maja, Kumejima). It is estimated that it is possible to supply 10,600 MWh of electricity, which accounts for 10% of its total annual consumption, by developing 1MW-scale power plant. The Prefecture is aiming to develop new ocean resource energies jointly with Kumejima, based on this result.
OTEC performs better in terms of power generation capacity and efficiency when the temperature difference between surface seawater and deep seawater is larger. The temperature of surface seawater at the surrounding sea of Kumejima is 25.7℃ at annual average. The Prefecture mentions in hope,"Natural environment here is excellent (for OTEC) within the country. OTEC can generate power stably day and night. With this demonstration, it could become the model for islands not only within the country but also for abroad".
The Town pumps up 13,000 tons of deep sea water daily. According to the research result, With the expansion of intake pipe, it is possible to intake 100,000 tons of deep seawater, add 1.25 MW of power capacity, and supply 10,600 MWh of electricity annually.
Companies on the Island that relate with deep sea water generates sales of 2 billion yen and employs 139 people. It is calculated that, when using deep sea water pumped up for 1 MW-scale power generation facility, the economic effects of these deep seawater-related businesses would be 8 billion yen, generating 1,500 employments.
Project Promotion Section of the Town of Kumejima said, "We are aiming the town planning with deep sea water utilization as the pillar, and OTEC is the core. Although cost issues remain, the dream of local development is expanding."
