Ofgem wants answers from electricity system operator (SO) National Grid on why it spent more than three times its budget to procure additional contracts with -suppliers of a specialist network service – Black Start – for 2016/17. The SO wants to claim back £113 million from customers, because it said the rapid closure of coal plant forced it to buy more services. Ofgem is consulting on whether to allow the change and wants responses by 6 July. Its conclusion – and who pays that bill – will not be known until 24 August.