[Aachen]

It won't be zero so spreading it across enough people might already solve it. If that still leads to insufficient demand during the hottest weeks, idk, it's energy, surely there's something useful you can do? Store it for next week, pre-heat water for the nearest steam engine (e.g. gas power plants are steam engines running on methane, so if they have to heat the water by fewer degrees.. The problem will be finding a steam engine close to the heat source), supply it to an industrial process that needs temperatures above ambient (egg breeding for vaccine production? Idk), create electricity from the temperature differential between this system and the Thames water using the Peltier effect

I've surely got a too naïve view of economics but if the goal were to not waste resources then there will be things you can do before dumping it into the hot summer air