Letter Alan J Sangster: In the timely and challenging article by Rob Edwards, many of the important engineering issues raised by the urgent need for Scotland to transition to an electrical power system based on renewables, are addressed (Can green energy revolutionise the Scottish economy?, State of the nation, April 2). However, the article rather slides over the question of storage, which is arguably key to a successful and effective renewables based grid system. Massive energy storage systems (MESS) can be based on a variety of technologies ranging from compressed gas storage and hot water thermal storage in cathedral-sized caverns, to massive batteries and capacitors. In Scotland, the most attractive route to storage is high-altitude gravitational storage of water in lochs. But useful sites are limited. A more promising technology, which is also relevant to Scotland, is low-level gravitational storage of water in very large artificial lagoons. Such offshore systems are already being built and tested in Copenhagen and Kattegat in Denmark, Florida, Tamil Nadu in India, Bahrain and China. MESS in the Firths of Forth, Tay, Moray and Clyde could potentially supply our cities while the Tesla style grid-connected massive batteries, currently being proposed for Australia, could power our towns.
Sun Herald 9th April 2017 read more »