Intermittent approach to renewable energy | Letters
Intermittency - in one word, the main problem facing many (not all) forms of renewable energy; in the UK, principally wind and solar, and now tidal (Hinkley Point C got the go-ahead despite its cost. So why not Swansea Bay? 27 June). So far, electricity from these renewable sources has been in modest amounts, and intermittency has been dealt with (I simplify, but only slightly) by backing-off gas-fired combined cycle (CCGT) plant which, together with nuclear, forms the backbone of the UK electricity generating system. When the wind is not blowing or the sun is not shining, CCGT plant is there to take the strain.
But this simple strategy fails if wind, solar, and now tidal presume to take over this backbone role. Smart metering (affecting consumers' usage patterns) and international power exchanges can help, but the main action has to come from energy storage and regeneration plant, involving a new infrastructure to supplement hugely the existing pumped storage capability. This is bound to have serious cost implications, and until this is openly acknowledged, direct comparison of projected MWh costs from any intermittent renewable source with corresponding MWh costs from non-intermittent new nuclear generation is fundamentally invalid, and likely to be badly misleading.
Jim Waterton
Glasgow