Agreement to Build OTEC Plants in Bahamas

by Larry Smith

Ocean Thermal Energy Corporation of Lancaster, Pennsylvania has signed a Memorandum of Understanding with the Bahamas Electricity Corporation to explore renewable energy resources in the Bahamas.

The agreement calls for the construction of two 10 megawatt OTEC (ocean thermal energy conversion) plants on New Providence and Andros in a "first of its kind' deal to commercially produce clean energy, potable water and sustainable aquaculture using ocean water. BEC's peak load is 230 megawatts.

"If the MOU achieves its full potential this would put us on the cutting edge," BEC chairman Michael Moss said. "It's going to mark our first tangible steps in renewable energy. We may not have pursued other renewable energy opportunities as aggressively as we ought, and we're going to look more seriously at solar and tidal energy."

He was acknowledging that the Bahamian record of the last few years on this front has been dismal. Although the government initially embarked on some major initiatives - including a national energy policy, a call for production of renewable energy by the private sector, an energy efficiency programme and a regulatory review, these efforts have largely fizzled.

BEC cancelled its two-year renewable energy tendering process with nothing to show for it. The government has been unable to agree on the implementation of a waste-to-energy plant at the Nassau landfill. And reform of the legal and regulatory system is still some ways off. Meanwhile, BEC is making enormous investments in conventional generating plant that will be in use for the next 20 years.

OTE Corporation is already working with the Baha Mar resort now under construction on New Providence to use ocean water for a district cooling system that will reduce electricity demand for air conditioning by more than 80 per cent.

That $80 million project will air condition the entire resort - about 14,000 tons of cooling - using one-eighth of the energy consumption that would be required for conventional cooling. The plant will pump 40-degree Fahrenheit sea water from a depth of about 3,000 feet off Goodman’s Bay. This chilled water will be sold to Baha Mar at a per ton hour rate comparable to an electrical-based system.

OTE is currently operating a pilot plant for the co-production of electricity and potable water in conjunction with the Natural Energy Laboratory of Hawaii. The BEC deal is expected to lead to the world's first utility-scale OTEC power plant.

Ocean thermal energy conversion is a base-load renewable energy production process particularly suited for tropical zones. It uses proven technology to exploit the temperature differential between warm surface water and cold deep water to generate both electricity and potable water.

An OTEC plant can produce up to 800,000 gallons per day of fresh water per megawatt of installed gross electric power capacity. And the vast quantities of nutrient-rich and virtually pathogen-free deep water drawn  by an OTEC plant offer significant opportunities for fish-farming.

While the technology is proven and the physical conditions in the Tongue of the Oceran between Andros and New Providence are ideal, OTEC has yet to be implemented on a commercial scale.