The temperature difference between the warm surface water and cold deep seawater can be used to generate electricity by means of Ocean Thermal Energy Conversion (OTEC). Near tropical islands this temperature difference is the largest. Due to the high oil price, the OTEC technology is becoming a viable and sustainable alternative. Watch the video below to understand how this technology works. At the moment, several companies are setting up production facilities in Hawaii, Cayman Islands, Martinique and Curacao. Netherlands based startup Bluerise is working together with Curacao airport to pilot their Ocean Thermal Energy plant as part of an eco-industrial park.
A multi-purpose Ocean Thermal Energy plant
Similar to the air-conditioning system from Evening Breeze, Bluerise also targets the hotels and resorts. The Seawater Air Conditioning (SWAC) system is an eco-friendly alternative saving up to 90% in electricity usage over conventional A/C systems. This is very significant if you realise that A/C accounts for approximately 60% of total electricity consumption in many tropical islands.
The ocean thermal energy plant can also provide fresh water by low-cost desalination. Instead of using chemicals and energy intensive desalination technologies such as reverse osmosis, OTEC can produce clean fresh drinking water by means of evaporation of warm water and condensation using cold water.
The cold deep seawater can also be applied to cool crops enabling agriculture in arid coastal regions. The cold water runs through a network of pipes buried just below the surface, cooling the top soil layer and causing dew condensation. This allows crops to grow in more a simulated humid environment.
Another application of ocean thermal energy conversion is in aquaculture. Due to the rich nutrients contained in deep seawater such as phosphates and nitrates, fish farms can benefit and breed healthier fish. There is no need to use biocides or other artificial feed impacting not only fish health but also bottom line economics.