Orkney’s fast-flowing tidal inlets and coastlines battered by ocean swells have been test sites for fledgling wave and tidal stream energy prototypes. More are being expanded and plugged into the UK grid. One Scottish ocean energy company, Orbital Marine Power, has been testing tidal stream technologies that are ready to go large-scale, including a giant turbine capable of powering over 1,700 homes. With the first “O2” turbine due to be deployed this year at Orkney’s European Marine Energy Centre (EMEC), and another to follow in 2023, it is one of several commercial marine energy farms that could contribute up to a fifth of the UK’s power needs. Bringing a renewable energy source like ocean energy to market has, as with wind and solar, demanded extensive research and development. But tidal and wave energy lost significant momentum in the wake of the 2008 global financial crisis.
For technical reasons, wave energy itself has proven difficult to harness. Of the countless wave generator prototypes designed and tested in the last 20 years, very few have reached commercial scale despite much promise. Despite the success of the worm-like Pelamis Wave Power energy converter — the first wave-based generator worldwide to be connected to the national grid in 2004 before the project went into administration a decade later that wave energy is currently being perfected at a reduced scale to remotely power smaller coastal communities. Marine energy industry group Ocean Energy Europe is attempting to harness this growth with its 2030 Ocean Energy Vision. By bringing the marine energy price down to a competitive 90 euro ($108) per megawatt-hour (MWh) in the next decade — the same price as wind — the ultimate goal is to increase output to 100 gigawatt hours (GWh), which it says would cover 10% of Europe’s current electricity needs. Targets remain a long way off, with just 1.5 MW of tidal stream capacity added in Europe in 2019, and just above 0.5 MW for wave energy. By contrast, around 3.6 GW of offshore wind capacity was installed across Europe that year. Such ocean energy growth will be dependent on the subsidies and feed-in tariffs, and falling price, that have allowed solar and wind energy to expand massively in the past two decades.