Firm reliable power capacity margin relative to peak power demand as a function of wind, solar and nuclear power penetration for the GB power system. Firm reliable capacity consists of all power generation capacity except wind, solar, and wave. Data differentiated according to commissioning institution. Industry and Government: BEIS (2018), BNEF (2018), Carbon Trust (2016), CCC (2015), National Grid (2018). Academia: Heuberger et al. (2018), Pfenninger et al. (2015), Price et al. (2018), Zeyringer et al. (2018).