June 2014: The International Renewable Energy Agency (IRENA) has published a series of technology papers exploring the potential for power generation and other sustainable applications from ocean energy. The papers cover the main features and current status of four technology types: tidal energy; wave energy; ocean thermal energy conversion; and salinity gradient energy.

The four Technology Briefs, launched in June 2014, are the first publications by IRENA on ocean energy technologies. The briefs examine the development readiness and deployment dynamic of each technology, including: process and technology status; costs, cost projections and performance; potential and future prospects; and challenges, barriers and drivers.

Presenting on the publications, Linus Mofor, Analyst at the IRENA Innovation and Technology Centre, noted that, while the potential of ocean energy is estimated at 100-400% of global electricity demand, its contribution to the global energy mix is expected to continue to be small in the short to medium terms.

The Brief on tidal energy describes progress and status in three technology categories: tidal range technologies, with well-established commercial viability; tidal current technologies, entering the demonstration stage; and hybrid applications, with great potential if integrated in new infrastructure for coastal zones. Overall, with total global capacity in 2012 standing at only 520 MW, IRENA estimates the total technically harvestable tidal energy potential located near coasts at one terawatt.

The Brief on wave energy notes that, despite over 100 pilot and demonstration projects over the world, only a handful of technologies are close to commercialization. Owing to limited commercial experience, the estimates for levelized cost of electricity in 10 MW demonstration projects is high, at €330-360/MWh, but IRENA finds considerable scope for economies of scale and learning, and important reductions in cost at higher deployment levels over time.

Describing ocean thermal energy conversion as having the highest potential of all ocean energy technologies, the respective Brief notes that: these technologies could supply the total worldwide power generation capacity with zero impact on ocean temperature profiles; 98 countries and territories have been identified as having viable resources; the technologies are particularly suitable for remote islands in tropical seas; and existing barriers include high up-front capital costs and lack of experience in building at scale.

Salinity gradient power, created from the difference in salt concentration between fresh and salt water, currently at pilot stage, has an estimated total technical potential of 647 GW, but is facing funding issues due to a lack of reliable financial support mechanisms.

As part of its work on ocean energy, IRENA has also carried out a patent landscape assessment to assist policy makers and invertors in investment decisions, to be published as a report. [IRENA Ocean Energy Technology Briefs Website] [Publication: Tidal Energy] [Publication: Wave Energy] [Publication: Ocean Thermal Energy Conversion] [Publication: Salinity Gradient Energy] [IRENA Assessment of Ocean Energy Technology Innovation Webpage] [IRENA Presentation on Ocean Energy]