Hydroelectricity from Teddington Lock!

Osbaston Screw Turbine

Ham Hydro plan to install 4 larger versions of these 'Archimedes Screw' turbines at Teddington lock. (Picture copied from http://talybontenergy.co.uk/?p=1177)

I have just registered as a supporter of Ham Hydro’s attempts to build a power station in the weir at Teddington Lock. Having registered as a supporter, I thought I would find out about the scheme! OK. I know that’s the wrong way around, but sometimes things happen that way. But I have been really disappointed. Despite the fact that they are asking local people to buy shares in the scheme to the tune of £2.4M, they have published almost no information about the scheme!

Questions. As I have mentioned previously, our choices about energy require clear thinking and clear accounting both in terms of energy and money. So here, for example are some of the questions about this scheme to which I think Ham Hydro should already have published answers without having to be asked.

  1. How much electricity will this scheme generate each year?
  2. How will the amount generated vary between winter and summer?
  3. What happens if there is a drought?
  4. What happens if there is a flood?
  5. Why is this unusual form of electricity generation a sensible choice?
  6. Why would £10,000 spent on shares in this scheme be better for the environment than putting solar panels on your roof?
These are just the first few questions that occured to me, but Ham Hydro have chosen not to publish answers to any of these figures.
Answers Here are my guesses at some of the answers and why they are important from both an environmental and an economic viewpoint.
  1. After asking questions on the web site I have now been told that the scheme will conservatively generate 1.92 GWh of electricity per year – which corresponds to roughly around 220 kW or around 300 horsepower to give a motoring equivalent. If each unit (kWh) generated was worth £0.15 the scheme would have an income of £288,000 per year. This is just 12% of the total scheme cost.
  2. Teddington lock maintains an almost constant head between winter and summer, but the flow does change significantly. This pleasing web page tells me that the mean flow on the Thames at Kingston is 5.7 million cubic metres per day or 65 cubic metres per second. Applying the formula (mass of water per second x gravitational constant x height of drop) allows me to guess this corresponds to around 1200 kW possible generating power for a 2 metre head. But the scheme only draws 220 kW.  So if flow fell below 1/6th of mean flow then the  scheme might have to reduce generating capacity – the locks need water too! But it should be able to keep generating through a ‘normal’ summer.
  3. In times of drought I think the scheme would have to reduce generating output.
  4. In times of flood I don’t think the scheme could increase capacity to take advantage of the extra water, but the scheme would probably not be threatened physically.
  5. This web site claims that Archimedean Screws are fish friendly and suitable for low heads of water.
  6. My mate Nigel has just spent roughly £10k on solar panels for his roof and they seem to be generating around 3400 kWh per year. So if we all spent this money on solar panels then £2.4M would generate around 0.8 GWh per year. So this scheme appears to be about twice as efficient in its use of capital resources. But of course Solar PV is a much lower risk so that if only £1M was raised, the scheme would still be able to begin. [Figures updated on 20th June] Of course if we could somehow use the money to insulate people’s homes better and then get hold of some of the money these people saved then this would make the most sense of all!
Summary. I wish this enterprise all the best – but I can’t imagine the planet on which they live where they think people will cough up £2.4 million pounds without having any idea of what they are buying. This project offers big opportunities to raise consciousness of energy generation issues in schools and in the community. Ham Hydro’s current efforts are … well frankly pathetic, and they should get their act together or they will fail from a surfeit of goodwill and a lack of good planning and communication.

8 Responses to “Hydroelectricity from Teddington Lock!”

  1. Project Dirt Says:

    Hi Michael – I followed the link here from the EnergyShare website. I’m not a member of Ham Hydro, but also a “supporter”, as you are. Thanks for looking into this further, and posting more information. On the whole, it looks like the figures stack up if the group can carry out this ambitious venture.

    Just one obvservation on your point 1 – you state that the annual scheme generation income would equate to “just 12% of the total scheme cost”. Put another way that is a “payback period” of just over 8 years (assuming minimal maintenance costs) – which to me sounds very reasonable, and much quicker than many other renewable options. What do you think?

    Best wishes, Nick

    • protonsforbreakfast Says:


      Hi. I put the figure there just to get some kind of idea of the scale of the project as it sets the total income. But what would be the expenditure? I think maintenance would not be minimal. And then there is Security? Accountancy? It would be hard to imagine doing all that for less a few £10’s of thousands of pounds. My guess would be that actually the group plan a tie up with British Gas which would buy the electricity at a much higher price to satisfy their obligation to sell electricity generated by renewable means. Like you, the scheme seems to make sense, but I feel – disappointed – that Ham Hydro have published so little about the proposal.

      All the best


  2. James Heather Says:

    Hi Michael,

    My name is James Heather and I am a director of Ham Hydro CIC and also the project manager. First I would like to thank you for joining our energy share group as a supporter and for wishing us well in your blog.

    I would like to take this opportunity to briefly address some of the points you have raised although if you (or any of your readers) would like further information please get in touch with us via info@hamhydro.org or our website http://www.hamhydro.org.

    First we are not looking for the public to invest £2.4M. We are planning to borrow money from the bank and the share issue you are referring to will be for a much smaller amount. Since the banks will be providing a large amount of capital we have entered into detailed negotiations with them and provided equally detailed information about the project to them. When the time comes that we are ready to approach the public about the idea of a share issue we will issue a comprehensive prospectus which will enable any potential investors to make an informed decision about whether our project is a suitable investment for them.

    In the mean time we have provided information to the public which is designed to generate interest in the scheme and develop an awareness about what we are undertaking. We have always made ourselves available to anyone who was interested in gaining greater knowledge regarding the project via email, phone or at our office. As you will know from the extensive local press coverage and over 12 pages of google articles about Ham Hydro there is a lot of information available for anyone who is interested.

    In addition to using press releases, the internet and our website we have given to presentations to many local groups and societies and are already scheduled to give many more. We have had a stand at most of the large summer fairs including the Richmond and Ham Fair. We have also held a well publicised (via local papers, community groups, emails, schools and a poster campaign) public meeting at which we both presented a wealth of information and answered all questions the public had. We also took the opportunity to talk about the range of studies we have undertaken including Environmental Impact Assesments, Flood Risk Analysis and Fish Studies.

    We completely agree with you that this project represents an opportunity to raise consciousness of energy generation issues in schools and the community. In a fact we believe it provides a good platform to teach about sustainability in general along with the obvious focus on renewable energy. As such I have visited local schools and talked to them about potential projects. This has been met with much interest and several ideas are being developed. One school is looking at building a model of the scheme and studying how varying flow affects electricity production and other schools are looking at how the project could form the basis for coursework projects. We have also talked with the local universities and colleges and were happy to provide data to them for undergraduate projects. We have used the scheme as a reason to talk to schools about their energy usage and possible ways to reduce wastage. We have also tied up with the Ham and Petersham Low Carbon Zone as we feel both schemes are complimentary to aid their efforts to encourage lifestyle changes and implementation of energy saving measures in people’s homes.

    Thanks again for your support. Please do email us if you have any further questions.

    Kind regards,

  3. Hydroelectricity from Teddington Lock 2 « Protons for Breakfast Blog Says:

    […] my piece last week on HamHydro I got a very nice comment from James Heather about how in fact all the data was available […]

  4. Ed Says:

    http://www.inference.phy.cam.ac.uk/withouthotair/c8/page_55.shtml says just about all that needs to be said on these types of schemes. They only become “economic” because of a rather ridiculous government subsidy that would be better spent elsewhere. I demand my money back…

    • protonsforbreakfast Says:


      I disagree. It would be nice to live in a world where the price we paid for something reflected its true cost, including the environmental costs. If we did, then I would I agree that subsidies would just make things worse.

      However we live in a world of stupid subsidies. For example the government is helping me buy a bike!


      How bonkers is that! But more importantly, generation of electricity using fossil fuels puts CO2 into the atmosphere and we are not paying the economic cost of the harm we believe this will cause in coming decades and centuries. If we did pay the full cost, then fossil fuel would be expensive, and we not let a scrap of renewable energy go unexploited. Until then I think its broadly sensible – or at least not as mad as it seems – to subsidise ‘uneconomic’ but genuinely renewable energy sources.

  5. Ed Says:

    It would be worth subsidising things that actually make a difference, for example perhaps, smart energy meters, smart thermostats or domestic solar hot water panels.
    Bicycles and low-head hydropower are simply ridiculous photo-opportunity gimmicks, a distraction that make the politicians “look good” whilst achieving little for future generations, equivalent to bailing out the Titanic with a teaspoon, to borrow a phrase from the book. Long-haul air travel is another elephant in the room….

  6. Patrick Says:

    This scheme has the benefit of being 24/7 generation unlike PV
    I would like to see it all way down major rivers let us hope this goes ahead and demonstrates the power available . Collectively we need every scrap of carbon free energy we can find . good luck to it all

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