Options –
Continue to buy on the open market and be subject to the fluctuations of the market.
Fracking – called for by Tory Climate Deniers must surely be dismissed as unsafe and impractical besides taking a long time to bring to fruition.
Nuclear – probably makes sense for a 20-30% role – but is horrifically expensive and the time to bring new stations on stream is probably decades.
Renewables – could be the quickest option – although those in the Chilterns will be choking on their smoked salmon if planning rules for land based wind farms goes ahead. Could they not be sited by pylons? Problem is storage although a combination of solar and wind should cover most weather eventualities.
Cutting demand is the quickest of all – insulation of all buildings where practical should be mandatory for all property owners (landlords note). Rolling out electric vehicles could be speeded up although imposing 50 or 60mph on all roads would be fast and practical. I am sure road haulage firms are looking at their distribution networks. Would use of freight trains be practical with computer booking.