Vattenfall will start construction of the UK’s largest battery storage scheme this summer, to be located at the Pen y Cymoedd wind farm in Wales. This location makes use of the existing grid connections and means the batteries can be powered by the wind farm or directly from the grid. The 22MW battery system, known as Battery@PyC, will comprise of six shipping containers filled with BMW lithium-ion batteries. The new facility will help National Grid to maintain the grid’s system frequency at close to 50Hz. New strategies have been adopted to maintain the supply and demand balance as increased levels of renewable generation bring intermittency of supply. Vattenfall’s new facility will be able to achieve active power output within one second of registering a requirement, which is the fastest type of response available, known as Enhanced Frequency Response. The battery will respond to power fluctuations on the grid by pumping in power if frequency drops or drawing it in if the frequency is too high.
National Grid procured 200MW of Enhanced Frequency Response through a tendering exercise held in July 2016. Several projects were successful in the competition, including Vattenfall’s Battery@PyC. Capacity auctions have also been a successful route for new storage solutions. Increased use of battery storage will help to keep the system stable and increase the viability of additional renewable generation capacity. Government statistics show that renewable electricity capacity was 34.7GW at the end of 2016, 13.7% higher than one year earlier. This increase was largely due to an increase in solar PV and onshore wind capacity. Renewable generation made up 22% of electricity generation in Q4 of 2016, down from 27% the year before because of unfavourable weather conditions. However, solar power generation broke records on 26th May 2017 when it provided 25% of the country’s total demand as the UK experienced a hot and sunny day. Speaking of the new solar record, Duncan Burt, head of control room operations at National Grid said, “We now have significant volumes of renewable energy on the system…[w]e also have the tools available to ensure we can balance supply and demand.” Battery@PyC is expected to be operational in February 2018.