The Conservatives have said the government has spent more money on the coal industry than it has on marine renewables, so homeowners could be less able to compare energy sources.
According to the party, less than £3 million of the £50 million contained within the Marine Renewables Deployment Fund has been spent, while nearly all of the Coal Investment Aid fund, launched only a year earlier in 2003, has been used.
Greg Clark, shadow energy and climate change secretary, criticised the government for failing to make more progress in terms of renewable energy investment.
Mr Clark said: "Faced with this neglect from the government, it is little wonder that Britain punches way below its weight on renewables - we have the third lowest contribution from renewable energy in Europe, despite some of the best natural resources."
The government responded by saying that marine renewable energy technology is being constantly tested but remains a young science and no projects have yet met the necessary requirements for funding.
Coal-fired power stations may still be used in the UK until new nuclear reactors are completed and give people more opportunities to switch energy sources.
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