There have been two revolutions in global energy over the past decade: shale fracking in the US and renewables in Europe. While both have led to a surge of supply, Europe has paid three times as much, though this may change as solar costs fall. The IEA’s warnings of blackouts in Europe echo comments this week by the EU gas body Cedigaz, which said gas power operators are mothballing plants because they cannot compete with cheap US coal. The risk is that investment in gas plants will dry up.