<p>We are not aware of any such penalties in the last 10 years. However, the energy regulator, Ofgem has issued a statutory consultation on new licence conditions to improve access to the wholesale electricity market, including by requiring the eight largest electricity generating companies to follow a set of 'Supplier Market Access' rules when trading with small independent suppliers. The Consultation can be found at:</p><p>https://www.ofgem.gov.uk/publications-and-updates/wholesale-power-market-liquidity-statutory-consultation-secure-and-promote-licence-condition</p>