fixed price

It does that by agreeing a fixed price - or strike price - that they will be paid for each unit of electricity generated for 15 years into the future.

If the wholesale price is below this fixed price, the renewable generator gets paid a top up by a government-owned company.

It does this by agreeing a fixed price - or strike price - that they will be paid for each unit of electricity they generate for 15 years into the future.

If the wholesale price is below this fixed price, the renewable generator gets paid a top up by a government-owned company; if the wholesale price is above the strike price, the generator pays the difference back.

The unit lost more than $5bn, largely thanks to rising costs on fixed price military contracts.