What balancing the grid costs
What NESO spends each day keeping supply and demand matched: constraint costs (curtailment) when the wires are full, and everything else.
Questions
What NESO pays, minute by minute, to keep supply equal to demand: buying more power, asking generators to turn down, and holding reserve.
When the wires between where power is made and where it is used are full, NESO pays generators on one side to turn down and others on the far side to turn up. The payments are constraint costs, called constraints here; the generation turned down is curtailment.
Energy suppliers pay a charge, BSUoS (Balancing Services Use of System), that covers these costs, and pass it on in customers' bills. Generators stopped paying it in April 2023.
Yes. Choose a month and the totals are the same NESO daily figures summed for that month, as in State of the grid.
NESO publishes the daily figures a few days in arrears.