Have you read the report?
"In each half-hour trading period, each electricity generator bids the price it will accept to generate electricity, according to how expensive the electricity is to produce." This is not true for renewables, they bid in low to ensure all the available capacity is taken up safe in the knowledge that they will get paid their strike price or the marginal price and ROCs for every MWh they generate. They even get curtailment payments when the grid can't handle what they want to produce.
"Renewable generators who are part of the renewable obligation government scheme may profit from selling electricity to the wholesale market and by selling renewable obligation certificates (issued for each unit of electricity generated), but they may have already sold the electricity at a lower price ahead of this." What they don't tell you is these certificates are sold to the electricity suppliers who pass the cost on to the consumers. With a current price of around £59/ROC some offshore wind producers are getting £118/MWh on top of the wholesale price they achieved. How is this cheaper than gas when gas produced electricity was at an average of £84/MWh in 2024
"Contract for Difference (CfD)renewable generators selling into the wholesale electricity market will not profit as they receive their agreed ‘strike price’ whether the wholesale price is above or below this." What they don't tell you is that CfD generators have only paid back for three quarters in the last seven years and have received net payments of £8.9 billion. Remember this is on top of the wholesale price they got for the electricity generated.
Can you explain why "It would make sense that renewables are cheaper".