Millions of pounds are being spent in constraint payments from the UK’s National Grid to wind farm operators, effectively paying them to turn off their generators as the electricity is deemed to be at the ‘wrong time’.

The Institution of Mechanical Engineers warns in a new report 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 roadmap for the development, demonstration, and deployment of energy storage technologies in the UK.

In its new report, Energy Storage: The Missing Link in the UK’s Energy Commitments, the IMechE highlights energy storage technologies such as those based on cryogenics (‘liquid air’), flywheels, pumped heat, graphene supercapacitors, hydrogen etc. as potential ways the UK can start making the best use of its renewable energy.

‘At the moment, constraint payments for renewable based electricity generation makes up a relatively small proportion of the total, but as the installed capacity of these technologies increases in the future, the issue of such payments will likely become of growing public concern,’ says Dr Tim Fox, Head of Energy and Environment at the IMechE.

‘Virtually any form of energy storage could help alleviate this problem, by allowing surplus generation from intermittent renewable sources to be stored by power providers until needed for use at a different time when demand exists,’ he continues. ‘But the need is not just for electricity generation, which only makes up around 26% of UK energy demand, we also require storage for the bigger demands for heat and transport as they transition to renewable sources.’

The UK is committed to meet 15% of its overall energy demand from renewable sources by 2020, and faces a legally binding target to reduce greenhouse gas (GHG) emissions by 80% relative to 1990 levels by 2050. In Scotland, the devolved administration has set itself the additional target to deliver the equivalent of 100% of the country’s gross electricity consumption from renewably sourced generation by 2020.

The IMechE makes the following recommendations:

• Government needs to focus on heat and transport, as well as electricity. It is well understood that security of supply is crucial and that decarbonisation of the UK energy system is desirable, but in contrast to past thinking it should not be confined to simply having sufficient electricity generation capacity to ‘keep the lights on’.
• Government must recognise that energy storage cannot be incentivised by conventional market mechanisms. It is unlikely that the UK’s long-term decarbonisation objectives will be met without significant deployment of energy storage capability, yet there are no firm plans in the UK that commit to significant levels of energy storage.
• The UK must reject its obsession with ‘cheapness’ in the energy sector. Despite current concern over rapidly increasing energy costs, and the reactive political promises that are unlikely to be fulfilled, it is evident that whatever form of energy is used in the UK, costs will have to continue to rise into the future.