Tricks of the trade, by Jillian Ambrose

“Remember that solar really is a fair weather friend”

Much has been made over the past year of the energy sector’s investment hiatus due to the perfect storm of an impending general election and the Competition and Markets Authority probe. But without too much fanfare the UK has quietly increased its access to generation ­capacity by almost 1GW – due to the steady rise of solar alone.

This is true in the summer anyway, because output from the embedded solar panels will “net off” the reliance on the central grid to push peak demand to its lowest ever levels this summer.

There’s something pleasingly “David and Goliath” about the idea that millions of tiny solar panels can come together to produce an effect equivalent to almost two conventional generating units. But before we get too misty eyed, it’s worth remembering that this cumulative effect really is a fair weather friend.

Ironically, when the cold sets in and drives demand higher, these solar panels will effectively remove the capacity when we need it most. Renewables might be great news for decarbonisation, but for the market they are a trickier prospect, and getting trickier each year.

While the sun shines, lower levels of power will be needed, leaving more of the UK’s ageing fleet out of the money. But what about when it’s dark and cold and those sorely needed thermal units have been mothballed or closed due to low profits?

In a few years the capacity market should take care of that – and in the meantime at least we’ll have those sunny summer memories.