Because some of the windfarms still run on legacy contracts where they were incentivized by a guaranteed selling price for the power they produce. They are reimbursed for the loss of income they suffer due to curtailment.
Correct. The UK regulator (Ofgem) and thus UK consumers are being taken for a ride by windfarmers, who made these deals a precondition of building farms.
We will be paying them £2.5bn a year to not generate electricity by 2030