LondonAccord:The Power of Water

This page was initiated by Malcolm Cooper

Water Power and Tidal Power – A Provocation

Reader beware! The author is neither a professional engineer nor a qualified environmentalist. He is, however, a professional historian, and has also spent a large part of his working life serving Mammon in the City or doing battle with politicians of various hues on a wide range of public policy issues.

My intent in penning this short piece is simply to trigger a debate which doesn’t seem to be happening at the moment. What role should water play in our search for alternative energy sources or emissions mitigation schemes? To date, most of what I have seen deals with wind farms, nuclear power, cleaner coal, carbon capture and carbon markets. I am not about to suggest that we should adopt a large hydro-electric building programme. The UK is not Norway, and the problems, be they financial, physical or human are simply too high. There are, however, two other ways in which the UK might better harness one natural resource of which it has an abundance – water in motion. One of these ideas is rooted in the past and aimed at micro-generation. The other is there for future exploitation and could produce macro-generation.

In the pre-industrial age, the single largest source of energy was water. Any sizeable river and a large number of streams had at least one mill along its banks. Some had many. The technology was simple and fairly non-obtrusive. Flowing water was simply channelled through a narrow neck and across a water wheel. The wheel was most often connected to a mill-stone, and the grains which made up the staple content of most diets were thus produced. The rivers and streams are mostly still there, and in many cases so are the remains of whatever weirs or diversions employed to make the mill wheels themselves effective. Yes, some of these sites have been preserved as part of our natural heritage – and the author, historian that he is, would be the last man to suggest that any of these be tampered with. Most, however, have simply been abandoned.

I am quite prepared for engineers to tell me I’m talking nonsense or environmentalists to howl that I am advocating desecration, but it does seem that we could, without excessive investment or disproportionate damage to the environment, create a new network of micro-power stations simply by re-inventing the mill-wheel (you can find all the designs you need in museums and history books), connecting it to a generator and linking it to the local power grid. It sounds pretty easy to me. If it isn’t, then can we at least work out why it isn’t easy and find ways around the problems?

Moving from the past to the future, I would start by making one fairly basic observation. The United Kingdom has probably got the densest collection of major tidal estuaries in the world. Working clockwise from the southwest, I count 10: the Severn, the Mersey, the Clyde, the Tay, the Forth, the Tyne, the Wear, the Tees, the Humber and the Thames. There are a number of smaller rivers which could also be explored, but we will leave these aside for now. I will follow this up with another equally basic observation. We have built up, through the commercial exploitation of the North Sea Oil and Gas fields a world-class cluster of expertise in underwater engineering. And so my question is simply this – should the UK not be taking the lead in exploring, developing and exploiting the potential for using the tide to generate power?

I am aware that there will be serious environmental issues to deal with, and that we are talking about some fairly large capital expenditure. It does, however, seem that the basic technology should be simpler than that of a large off-shore wind farm, that the resulting structures will by their very nature be less obtrusive, and that careful study should minimize ecological interference. My physics might be wrong, but I don’t think that a tidal power scheme need involve any form of barrier under the entire width of an estuary. Similarly, my knowledge of marine life might be scanty, but I don’t see that creating structures to capture some of the energy created by the movement of water should be any more dangerous than the multitude of obstacles both natural and man-made that marine life has been coping with for years.

Well, those are my simply questions. It would nice to hear some complicated answers!