What would RWE and Uniper's combined share of British power be?

12% of the power on the grid. 38% of gas capacity. 42% of the gas that owners schedule. 27% of the gas NESO calls on. The answer depends on how you draw the market.

RWE has been named in the trade press as a possible buyer of Uniper. Nothing has been announced, and this piece is not about whether it should be. It asks a narrower question: is there a lack of competition among Britain's gas power stations today, and would running these two companies' stations as one fleet change the answer?

I started with no view. I have ended with a list of things that point one way, a list that points the other, and a short list of things nobody outside the companies can measure. All three are below.

Everything here comes from public data: Elexon's half-hourly records for all 83 gas units on the system, NESO's constraint cost figures, and published gas and carbon prices. It describes who owns what and when it runs. It says nothing about how anyone prices or bids, and I have not looked.