The world’s most northerly town, Hammerfest, in Norway, will be the first city to obtain its electrical power from a submarine station run by tidal currents. The 200 metric ton turbine is anchored on the seabed near Kvalsund. Its current capacity is 3 MW but it is to expand to 20 MW 36. The production would suffice to supply the needs of 1,000 homes. Costs have already reached $6.7 million (є5,73 million) and by entire project completion should have had a price tag of $14 million (є 11.97 million). The cost of produced electricity at $0.04-0.05 (Є0.034-0.043) is however triple that of hydro-plant produced power in Norway.
This tidal power will be integrated to the electricity mix in the local grid. The turbine is similar to a wind turbine. The current speed is 21/2 m/s.
A risk factor is involved as storms have wrecked ocean power stations before. Success of the undertaking could transform Hammerfest in a tidal turbine manufacturing center. Studies have been conducted for Garolim, Korea and the Messina Strait in Italy. In Canada and Russia the Darrieus type turbine have had the favor for some time. It remains nevertheless that often plans have been laid to rest because of a major drawback, the low-energy density. All things being equal the energy from a tidal current is one or two orders of magnitude lower than from a same diameter turbine in a barrage. It is felt that that disadvantage wipes out the savings provided by the dispensing with engineering works.
The authors do not stand alone lamenting that objections are continuously found to slow development of alternate ways to produce electrical power.
Commercial exploitation will have to solve the problems derived from waters either too deep or too shallow. The technology to be developed is likely to be based upon buoyant tethered systems and not fixed seabed approaches.