Recent developments and forecasts for renewable ocean energy systems

Renewable energy sources from the oceans include, among others, offshore wind, underwater currents, and wave energy. Growing awareness of renewable energy sources as a key element in sustaining future economies has lead to development in renewable ocean energy systems. Examination of worldwide investments in implementation of renewable energy technologies reveals that offshore wind energy is one of the fastest growing sectors. Strong growth in offshore wind power installations is anticipated over the next decade with estimates of in excess of US $1.8 billion in expenditures. Areas with high wind resource, shallow water and relatively close to existing electrical infrastructure will be developed using current turbine technology (1.5-3 MW). A second phase with larger and fewer turbines (up to 5 MW) are forecast for later in the decade. European waters represent 45% of the ´practical exploitable resource´ and are likely to represent 80% of actual installations to 2010. Development of systems to capture wave energy reached a milestone with the commissioning of the first commercial-scale power facility in Scotland. Several proponents have plans for prototype deployments in the next five years. Potential investments by companies engaged in wave power are estimated at over US$200 billion. Tidal projects have shifted from barrage systems to capturing tidal driven coastal currents. Two projects underway will place tidal fence across straits and turbines underwater to demonstrate the technology. Ocean-based renewable energy development will lag land-based systems because of upfront capital costs and difficulty obtaining the necessary financing due to risk. The technical capabilities, both engineering and management, exist in the offshore sector to undertake the size of projects envisioned