According to a new report by the Institution of Mechanical Engineers, millions of pounds are being spent in ‘constraint’ payments from National Grid to wind-farm operators in the UK. The IMechE warns that consumers will “continue to foot ever increasing bills for these payments”, unless the Government works with energy companies and industry to develop a clear energy-storage strategy.

Under existing market arrangements, if an energy company generating electricity is unable to feed its power into the National Grid because it is not required, it is entitled to ‘constraint’ payments. Figures from the Renewable Energy Foundation suggest that £8.7 million in such payments were made to wind farms in March — part of the £13,749,814 paid out so far this year. In 2013, wind farms received ‘constraint’ payments totalling £32,707,351.

In its Energy Storage: The missing link in the UK’s energy commitments report, the Institution highlights energy-storage technologies such as those based on cryogenics, flywheels, pumped heat and graphene super-capacitors as potential ways for the UK to start making the best use of its renewable energy.

Tim Fox, the organisation’s head of energy and environment, said: “We know that energy bills are going to rise in future, but unless we invest in energy-storage technology, these ‘constraint’ payments are set to become an unnecessary additional cost for the consumer. The issue of such payments has become a recurring concern of consumers, as they are effectively funding the non-supply of electricity from a range of generating technologies.

“Virtually any form of energy storage could alleviate this situation — by allowing surplus electricity generated from intermittent renewable sources to be stored until needed.”
Meanwhile, a report from the Royal Academy of Engineering suggests that there needs to be a radical overhaul of the way that the electricity system is managed. It says that the current grid can cope with “up to a 20% contribution from wind power without the need for significant upgrades to the system, using existing balancing mechanisms”.

Beyond that threshold, however, “managing the system will become increasingly difficult”. The report says that the variable nature of wind power will present problems when there is a mis-match between output and consumer demand; and if wind power continues to expand beyond 2020, days with negligible wind power could “present problems for security of supply”.

Professor Roger Kemp of Lancaster University, a member of the working group, said: “Wind energy will be only one of the tools available — alongside other generating technologies, better connectivity and demand side measures. All will need to be carefully integrated, using a systems engineering approach. As we progress towards a low-carbon future, the energy industry and infrastructure will have to evolve with — or ahead of — electricity demand to accommodate more wind.”