ABS has issued its first Approval in Principle (AIP) for a new concept renewable energy design in which a moored spar uses ammonia in a closed-cycle process to produce electrical power for a commercial utility grid. Unlike wind, tidal or solar power the advanced design for this Ocean Thermal Energy Conversion (OTEC) system can deliver constant output 24 hours a day. “This concept combines proven offshore principles with off-the-shelf power, technology and proprietary innovations, all assembled in a unique way,” says Ian Simpson, ABS Director of Offshore Technology and Business Development, Americas Division. Developed by OTEC International (OTI) LLC of Baltimore, Maryland, the approach converts liquid ammonia into gas in a heat exchanger using warm ocean surface water.