Liquid Energy ...

Toshiba have just pulled out of building a nuclear power station in the north west, and the UK finds itself in the situation of generating 20% of its electricity from nuclear plant that will be obsolete and possibly shut down within ten (?) years. The only new nuclear power station will be Hinkley C, coming on line in 2025 (?), and making up only half the shortfall (and that very expensively).

Renewables could fill the gap, and there certainly do seem to be a lot of wind turbines around – as well as a lot of solar power. But, as they say, what happens when the sun doesn’t shine and the wind doesn’t blow? Quite.

I keep a boat at Bradwell Marina on the estuary of the River Blackwater in Essex. The tidal range there is frequently 15 feet. Twice every 24 hours, a considerable quantity of water climbs up 15 feet and then drops back down. This pattern is repeated to a greater or lesser extent all around the coast of the UK. Surely this enormous energy source could be tapped?

The idea of tide mills goes back hundreds of years. There was one at the head of the River Roach near Southend; there still is one at Woodbridge although it has been converted into a marina. The principle is simplicity itself: build a reservoir with access to the sea. Allow the high tide to fill it up, then close the access channel. As the tide drops, allow the water in the reservoir to drain out via a water wheel. As the name suggests, in early days these were used to grind corn. However, replace the water wheel with a turbine driving an alternator and there is a source of electricity, and with a suitable design, it will work as the tide is falling as well as when it is rising. The process is entirely renewable subject only to maintenance costs.

Although the height of the high tide varies throughout the year with the waxing and waning of the Moon, it is little affected by the seasons and the weather, and the reservoir can be as large as you like. How about a great barrier along the east coast? The coast would be protected from erosion and the sinking of the land, and enough water could be stored for the entire electricity needs of the country. The Dutch have built such sea barriers – starting hundreds of years ago – so why can’t we do the same here using modern technology? Another thought; the vast Goodwin Sands off the Kent Coast are an on-going hazard to shipping. Why not build a great reservoir there?

The bad news, is that there was a plan for a 320 MW scheme in Swansea bay – that is about half a percent of the country’s electricity needs. The cost would have been £1.3 bn. The government rejected it earlier this year because the capital cost per generated unit of electricity would have been three times that of Hinckley C. Is it me, or was that an insanely short-sighted decision? 

Much of the cost of the Swansea project would have been for the construction of a nine km barrier, but that is prehistoric technology! The pyramids were higher tech than that, and once built, the barrier would have lasted virtually indefinitely. The turbines would have been sophisticated, but even they are hardly cutting-edge technology. No-one knows what cost-overruns will occur on Hinkley C, but given the history of the nuclear power industry and the state-of-the-art technology, I’ll bet they will not be modest.

Hinkley C has a design life of sixty years. After that, it’s just a large area of very expensive highly dangerous scrap that will cost goodness knows how much to make safe. And in case anyone has forgotten, Hinkley C is financed by the Chinese and French and built by the French. How’s that for ‘Taking back control?’

I am not against nuclear power, far from it, but even its most ardent supporters would never claim that it is a low risk technically or financially.

No, the Swansea Bay decision was very poor. Just another example of the inability of this government, with its retinue of mediocre second-raters and time-servers, to make any decision without f*****g it up.