Thank you for the article ‘Counting the kilowatts’ in the December 1999 edition of IWP&DC (pp12-13). I believe you put the various issues raised by the Environment Agency and Energy 21 about small hydro in the UK very clearly, but I would like the opportunity to respond to them.
There are 20,000 watermill sites and weirs in the UK, with a potential installed capacity of 600-1000MW. Nature has conveniently distributed this low density energy resource all over the world but modern power engineers can only think in terms of gathering it all into the grid system and re-distributing it again, with significant power losses and complicated tariff structures. I believe it should be used on site in parallel with the grid asynchronously or as a stand-alone synchronous supply, to offset avoidable costs and pollution from conventionally generated mains electricity — this is how we use hydro power at Coaley Mill.
In the UK two recent reports, by the House of Lords Select Committee on the European Union and by the House of Commons Select Committee for Renewable Energy, both recognise that small and micro hydro power have a minimal environmental impact. Yet the Environment Agency (EA) still produces a long list of potential impacts that they insist on considering for each individual site on the same river, often within a few hundred metres of the next site. What would the vehicle industry or house builders do if they had to meet similar environmental criteria for each vehicle or house built?
I would like to query the requirements of both Energy 21 and the Environment Agency, both of whom make life more difficult than need be for our sustainable industry.
Jackie Carpenter of Energy 21 states that the development of small hydro in the UK is on a learning curve – but do we need a demonstration site costing £0.5M for 50kW or £10,000 per installed kW? What will it demonstrate? It will confirm to the Environment Agency that low head micro hydro power is a non-profitable, expensive source of energy that needs subsidising as a charitable trust. Our industry needs projects that are good examples of modern technology. By combining two adjacent low head mill sites and providing one significant modern hydro power site that will stand up financially, Ebley Mill could provide a significant example in the UK.
Paul Bailey of the Environment Agency has listed many regulatory concerns, most of which are not applicable to these run-of-river mill sites. The EA has also let it be known that ideally all rivers in the UK would be meandering watercourses with no weirs or mill sites. But what about the EA gauging weirs and control weirs? What about the many navigation weirs — why are these not a problem? The impression I get from the EA is that weirs are only a problem when associated with hydro power.
Bailey wants gradients on watercourses, claiming this is necessary for the self-cleaning action of the river. Again the EA only appears to apply this criteria as an excuse against hydro power. The River Thames has 22 weirs with horizontal channels over 140 miles — no hydro power, only a few weirs with fish passes and they claim salmon are now returning to the Thames each year. The same is true of other rivers in the UK. Some of the finest rivers in the UK have little or no gradient over much of their length. These watercourses do not silt up any more than other rivers but provide some of the best fishing rivers in East Anglia, Hampshire and Wiltshire which are among the flattest areas in the UK.
My plea to the EA and Energy 21 is can we please progress with positive modern examples of hydro power in the 21st century that will demonstrate:
•Recognise the advantage of combining mill sites for effective modern hydro power.
•Recognise the advantage of fewer, more effective weirs and control gates, offering the EA improved river control.
•Recognise the advantage of clean watercourses for both flood prevention and the environment.
•Recognise the fact that water will flow in horizontal channels which, when correctly constructed, will remain clean.
•Recognise the benefits of hydro power installations to aid water pollution control.
I look forward to the day when the UK Environment Agency as a whole becomes better informed about small and micro hydro power and does more than quote its regulatory functions.