Not that I have any stake in the accuracy of electricitymap's statistics, but I don't think there's any point seperating out OCGT from CCGT generation. OCGT makes up a negligible share of realised generation (and indeed, even generation capacity is rather limited). The few plants that are still in operation need very specific market conditions to make their operation worthwhile, especially considering that 3x CO2 output means 3X fuel input, and 3x fuel costs. It's better to think of them as grid-stability mechanisms, like diesel generators, or the industrial load-shedding schemes.