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Abingdon Hydro

20 February, 2015 0 Comments
Trees by Abingdon weir, 19th Feb. '15

Trees by Abingdon weir, 19th Feb. 2015

They’ve been cutting down trees by Abingdon weir. This is to make way for Abingdon Hydro, a scheme to install two Archimedes screws by the weir to use the difference in height above and below the weir to generate electricity. I can’t find any figures on the Abingdon Hydro site that show clearly how much energy they expect to produce. However, my calculation based on the average 55kW* output for the scheme quoted on the Abingdon Hydro website and Ofgem’s 2011 electricity consumption figures is that in a year, the scheme could generate the equivalent of enough electricity to supply the annual energy needs of 146 houses.

The Feed-In Tariff

It’s important to understand that none of the electricity from this project will actually go to any particular houses in Abingdon or elsewhere. There are small and micro-scale hydro schemes around the world that directly power individual houses and small communities, generally in remote areas that would otherwise be without electrical power. However, any electricity generated by the Abingdon Hydro turbines will feed into the national grid through Scottish and Southern Electricity. According to the schemes website, Abingdon Hydro expect their electricity to either be sold to the grid at the feed-in tariff, a rate determined and subsidised by the government, or to a larger green electricity generator.

Friends of the Earth have this to say about the governments feed-in tariff,

‘The feed-in tariff (FIT) is a payment to people generating their own electricity from renewable sources. The electricity you generate and use during the day is free, and you also get paid for every unit that you don’t use but export back into the grid.’

As you can see from this, the expectation is that micro-generation projects are generating electricity for personal use or for the use of a community and then ‘exporting’ whatever is not used back into the grid. Abingdon Hydro, on the other hand, are proposing to only export to the grid and will not be generating electricity for local use.


So, the electricity won’t be directly for the community as such, but will it be ‘green electricity’ nonetheless? The first thing to look at is the cost of installing the turbines, their connection to the grid and the associated infrastructure costs. It isn’t clear from the Abingdon Hydro website which turbines will be installed at the weir. Perhaps, like much of the detail of the project, this is still unknown. However, if they choose Landustrie, the manufacturer of the screw used at Osney Lock Hydro, pictured on the Abingdon Hydro website, then the two estimated 9 tonne chunks of engineered metal will be transported by land and sea from Sneek in the Netherlands. This, along with the relative inaccessibility of the site means that there will be considerable carbon outlay on transport, installation and infrastructure works before the first watt of power is generated. There is no indication on the website of whether a calculation of this carbon cost has been made by Abingdon Hydro.

An Investment in the Future

Whatever the cost may be, it is not unreasonable to have a higher capital and carbon outlay on something that will bring the longer term green benefits of sustainable, low carbon power generation. But will the scheme generate an amount of power that achieves this goal? This is a very small-scale scheme – what is termed a ‘micro-generation’ scheme. At best, it will provide the national grid with a trickle of power at certain times of the year.  Scottish and Southern Electricity will install a meter for the scheme which will measure how much electricity the turbines have generated each year.  Even in a successful year, this meter will show that the weir has produced enough electricity for fewer than 150 average homes over a year. However, because this power is being fed directly into the grid, it is not clear that the power will in reality ever reach any home. There are big fluctuations in the demand for electricity throughout the day and the grid brings reserves in and out of service to match this.  Against this, the arbitrary trickle from the turbines at Abingdon Hydro, dependent on variable river flow and canoeists (the scheme has agreed to provide a button at water level that will allow canoeists to open gates on the weir that allows them to train but reduces the flow to the turbines), is insignificant.  It appears to me that the weir scheme may not actually make any contribution to the nation’s power supply. The company would, however, still receive a payment for this non-contribution.

Proof of Concept

Could the scheme be regarded as a ‘proof of concept’, pointing the way to potential future, sustainable, power generation? Not really. As mentioned above, it is an established technology that has been used in numerous projects around the world – it can certainly make economic sense if you are directly powering a small village or a single property. Proof of concept would also imply that if successful, more turbines would be installed along the Thames and this would become a pattern for electricity generation. That can’t happen. There are very few places along the Thames suitable for turbines and even if there were more suitable locations, the cumulative effect of the number of installations required to make it a useful source of power would reduce the flow of the river, rendering the screws ineffective.

An Amenity

One of the aspirations expressed on the scheme’s website is that it will become a ‘visitor attraction’, bringing tourists to the town. However, the river, the weir, the lock and the lockkeeper’s cottage are already an attractive focus for this part of town. It’s difficult to see what the scheme is adding in this respect and I haven’t been able to find any examples of hydro schemes having brought extra visitors to a town. If we are to expect additional visitors then we would need the infrastructure improvements to match such as additional car parking. Currently, the car park at the adjacent Health and Wellbeing Centre is already full to overflowing on some days and additional cars would need to be accommodated elsewhere on one side of the river or the other. On a sunny, summer day the weir itself and the area around the lock also get fairly crowded so if extra visitors are genuinely expected or are going to be encouraged, this needs addressing.

A similar hope is expressed that it would be an ‘educational resource’, a place where schoolchildren could learn about green energy and sustainability. As the scheme would not be an example of either of these, however, it couldn’t fulfill this hope with any sincerity.


Looking at the Abingdon Hydro website, it does seem to be a project built on a sunny but rather narrow optimism. The website states ‘We live here and we want to make it something attractive that our town is pleased to own, not just an electricity generator but a local amenity’. To function as an amenity, it needs to be doing something useful. Until we see the facts are figures to prove that it can be something useful, it can only be regarded as a white elephant and a hobby for the scheme’s members.

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