AS a professional electrical engineer of some 50 years’ standing I think I can justifiably reassure Lewis Niven (Letters, March 25) that electrical engineering science can definitely guide mankind toward a future powered wholly by renewables. He is obviously correct to point out, as many previous contributors to the Letters Pages have done, that there is an intermittency and base load issue where renewable power systems are required to operate within a conventional electricity power grid. This is particularly true where wind is the primary source such as in Orkney.

But this concern is only really serious when applied to single wind farms or small islands or perhaps to small countries such as Scotland. At the continental level, which is the direction of travel of the renewables industry in Europe, these problems largely disappear as power is gathered, from wind, solar, wave, tidal, geothermal and biofuel sources located in geographically diverse terrestrial and coastal regions, into a unifying “supergrid” (see Trans-Mediterranean Interconnection for Concentrated Solar Power, German Aerospace Centre (DLR), April 2006). This evolving scenario is a major reason why Scotland and the UK electorate would be wise to vote to reject Brexit in the European referendum in June.

It is perhaps worth noting, in relation to the often expressed “base load” anxiety alluded to by Mr Niven, that developments in massive energy storage (MES) systems are evolving steadily with the possibility of technologically routine, but infrastructure intensive, sea-level pumped-hydro representing a significant break-through in this sector. As “fossil-based generation capacity is aggressively reduced”, to quote Mr Niven, so a Europe-wide renewable power supply and storage system should be aggressively implemented. Progress in realising such systems is limited only by the political will of governments to release or encourage investment.

Alan J Sangster,

37 Craigmount Terrace, Edinburgh.