Solar and wind energy, combined with batteries gas as a backup are the cheapest new energy sort and are can be built fastest.
This is shown in a study for energy sources to fuel the spiking AI energy demands, which compares these systems with the prototypes for small modular nuclear reactions. It should be noted that the ideal solution in this study relies partially on offshore wind, which may be more readily available in the UK then elsewhere. You can find the study here (but take care the scientists could not make their content work on firefox): https://microgridai.centrefornetzero.org/
US studies also show how renewables are cheaper than coal as an energy source for most location in the US.
