The CfDs pay either party the difference. Their effect is to make the cost of that electricity guaranteed, it's actually a remarkably cost effective mechanism.

The subsidy is that different technologies secure a premium on the CfD. For a UK solar farm the strike price most recently was £65 per MWh. In case you were wondering no, nobody will run a gas power plant for £65 per MWh, even before Trump's war spiked price 50-100%

Yes, the offshore wind farms are significantly more expensive than a solar CfD, their strike prices were close to £100 and for that much money (adjusting for inflation) you could definitely get interest from gas plants, especially before the war - but now we're into the weeds about platform diversity. A Middle East war seems like a particularly stupid time to insist we shouldn't desire diversity...

Because of how summer works, this "But solar energy is expensive, gas is cheaper" is going to take a break for a few months because it will seem very silly, but it won't go far, expect it back in autumn.