As electricity generation patterns change across the UK, possible network capacity deficits across the transmission system have been identified by National Grid in its Electricity Ten Year Statement (ETYS). The outlook report predicts higher flows of electricity from the periphery of the network as more nuclear and renewable generation comes online, while coal generation simultaneously declines. Wind generation is expected to grow at unprecedented levels, particularly in Scotland where 5.6 GW of onshore wind is currently in operation and 2.2 GW is awaiting construction. Offshore wind capacity presently stands at just 190 MW, but a further 4.1 GW has planning permission, which will result in increased flows from Scotland to the south, but conversely, when wind speeds are low, increased network capacity will be required from south to north to supply Scotland.
The development of transmission-connected battery storage would be an important tool in easing the requirement for cross-country transmission of power. Under National Grid’s Future Energy Scenario, which considers different paths for the energy future, its “Consumer Power” scenario sees battery storage of 18.3 GW being in place by 2040.
Another consideration is the expectation that low-carbon generation in the North East will increase, but the Midlands will see reduced generation resulting in a requirement for increased levels of transmission between the regions. Meanwhile, it is expected that stress will be put on southern networks as interconnectors export power from the UK.
Where capacity deficits have been identified, a Network Options Assessment process will be conducted and investment recommendations will be published by National Grid in January 2017.
The Gas Ten Year Statement, which looks at entry and exit capacity on the transmission system, was also published last week. Gas-fired generation has been the preferred thermal generation since 2015, supporting demand for gas, but gas generation is being used more flexibly due to increased levels of renewables. At the same time, residential demand for gas has declined due to energy efficiency improvements. Views on the future of gas and how it will affect the gas network are being sought, with the aim of publishing recommendations to the government by November 2017.