The UK's CfDs are adjusted for inflation each year, so that's not an issue, and the cost of specific renewable energy installations is much more predictable tha

The UK's CfDs are adjusted for inflation each year, so that's not an issue, and the cost of specific renewable energy installations is much more predictable than natural gas - most of the cost is paid up front to construct them in the first place. The difficult part is that there isn't really any market-based way to set the price after the fact; the way the UK does it is via a reverse auction where anyone whose bid is too high doesn't get to build their wind farm, and that obviously doesn't work if it's already built.