Interconnector capacity between England and Scotland must be quadrupled over the next decade to match up growing supply north of the border to where demand is greatest, a former energy minister has warned.
Charles Hendry, who was minister of state for energy from 2010 to 2012 in the coalition government, told the environment audit committee this week that insufficient cash and work are being devoted to upgrading the UK’s grid.
He said: “At the moment, there is 6GW of interconnectivity between Scotland and England. Just with known offshore wind development, that needs to grow by 15-20 GW in the next decade and at least 25 GW by 2035.
“There is nothing like enough work and money being allocated to ensure that (areas) where some of these resources are greatest can bring power to where it is needed.”
Hendy told the committee, which was taking evidence about tidal energy as part of its wider inquiry into renewable technologies, that the UK and Scottish governments must develop a much more “common” approach to energy.
And Hendry, who conducted a review of the Swansea Bay tidal range project for the government, said the Contracts for Difference (CfD) process is not really fit purpose for such long-term schemes with big upfront capital costs.
The upfront costs of building the sea walls, which are required to capture the water in the incoming tides and then release it through turbines to generate electricity, are high for tidal reach projects.
However, advocates of the technology argue that once these are paid back in 30 to 40 years, the only significant capital costs are replacement turbines, enabling very cheap electricity to be generated over the rest of the project’s 120-year lifespan.
Hendry said: “We need a formula, which CfDs don’t adequately do, which enables us to deliver ultra-long-life projects. When the costs are paid back, it gives us almost free electricity for decades to come.”
Henry Dixon, chairman of the Tidal Range Alliance, told the committee that the sea walls would provide additional financial benefits by helping protect coastal areas against rising sea levels.
He also said that three of the offshore areas best suited for tidal range developments- Somerset, north Wales and Merseyside-already have substantial grid infrastructure minimising the need for expensive upgrades.
Dixon also said that as well as providing a low-carbon source of baseload power, tidal range projects could provide storage because the release of the water through the turbines could be held back.
Sue Barr, chair of the UK Marine Energy Council, said recently conducted analysis shows that the sophisticated nature of the UK’s marine engineering and shipbuilding supply chains means the alternative tidal stream technology could achieve faster cost reductions than those achieved by the offshore wind over the last decade.
She said that policy support, such as a dedicated ‘pot within a pot’ for tidal range projects within the CfD auctions, would enable the technology to be commercialised.
Tidal stream works by generating electricity from specially designed turbines laid in current fast-flowing, offshore currents, such as in the Pentland Firth off the Shetland Islands, where the world’s largest such project is being developed.
Barr said: “We believe it can be cost competitive with other forms of renewable energy like offshore wind by the early 2030s.
“If we get a strong signal we know we can bring down costs for tidal stream on a trajectory faster than offshore wind.
“If we can find ways to bring these projects forward, we will see very strong institutional financial support.”