Frequently asked questions (FAQs)

Answers to nearly everything you could want to ask about Reading Hydro! If you have questions that aren’t answered here, do get in touch. Or if you want to help us answer questions like these, why not get involved?

What is a hydroelectricity project?

Wherever water falls a decent distance there’s an opportunity to generate power. In centuries past, waterwheels would turn machinery to mill flour. Nowadays Archimedes screws and other hydro technologies have replaced waterwheels and electricity generators have replaced millstones.

How did Reading Hydro start?

In 2013 different ideas for community energy projects were being kicked around Transition Town Reading’s Energy Group. In early 2014, after discussing these ideas with the Greater Reading Environment Network, they came together and The Reading Sustainability Centre (TRSC) was formed. TRSC started the development of a hydroelectric project on Caversham Weir. In 2017 the project was transferred to Reading Hydro CBS Limited to take it forward.

What is a Community Benefit Society (CBS)?

Reading Hydro is a Community Benefit Society (CBS). This means that we’re a democratic co-operative that benefits our community and returns surplus income to it. You can find out more about community benefit societies here and here.

Has this been tried before elsewhere?

 There are already plenty of other community hydro schemes across the UK. Upstream on the Thames there are Osney Lock Hydro in Oxford and Sandford Hydro, and downstream there’s Sonning Hydro. Across the country there’s plenty to be inspired by: Whalley Hydro in Lancashire, Rumbling Bridge in Kinross, Callander Community Hydro near Loch Lomond and many more.

An example of a community hydro

Community Energy England have a link to a video about hydro-electric schemes, based on a 46kW 2.9m Archimedes Screw, or direct link

Who runs Reading Hydro?

Because Reading Hydro is a Community Benefit Society, it is run democratically by its members.

Our members elect directors, all of them volunteers, who take legal responsibility for the society and make sure it meets its aims. Find out about our current directors here.

What permissions were needed to build the hydro scheme?

 We got planning permission to install a hydroelectric scheme on Caversham Weir in May 2017. We also obtained permissions from the Environment Agency to use the water of the river Thames and operate a hydro scheme. Scottish and Southern Electricity Networks, the local electricity operator, has given us permission to connect to the electricity network.

Where did the money come from?

In 2015, The Reading Sustainability Centre was awarded a DECC grant to carry out preparatory work. A Pioneer share offer and a grant from the Reach Fund in 2018 enabled us to commission preliminary designs, and run a main share offer.

The main share offer and follow-up offers in 2020 and 2021 raised the £1.15m needed to finalise the design and build the scheme. Much of this came from nearly 750 individual investors, mostly local. We also received institutional investment from Co-ops UK.

Can people still invest in the project?

Our community share offers have raised all the core funding needed to complete the hydro scheme. However we still welcome donations and small grants towards environmental work associated with the scheme, and to support future educational activities. Please contact us, putting ‘Donate to Reading Hydro’ in the subject headline. 

How did the construction happen?

Reading Hydro volunteers began clearing undergrowth and rubbish on View Island in May 2020, and then constructed the fish pass and turbine house over the remainder of the year and in early 2021.

Land & Water, our civil engineering contractors, started on site at the beginning of October 2020 and completed the concrete structures in March 2021. 

A specialist contractor laid a conduit under the river using horizontal directional drilling. A team of trained Reading Hydro volunteers pulled a cable through the conduit, to connect the hydro scheme with Thames Lido, our main electricity customer.

The turbines were manufactured by Spaans-Babcock. The turbines, gearboxes, generators and associated electronic equipment were installed and tested by Spaans-Babcock between March and August 2021. 

When will the turbines start generating?

The system was commissioned and started generating in September 2021.

How long will the hydro scheme last?

The scheme is designed to keep generating for 40 years. Some of the equipment in the turbine house will need to be replaced during that time.

What happens in a flood or a drought?

Our operating agreement with the Environment Agency means that, for safety, we may have to shut down when the river flow and levels are very high. Generation may also have to stop during drought conditions if the Environment Agency requires us to stop taking water from the river. 

Who designed the hydro scheme?

A local hydro consultancy designed the fish pass and drew up early plans for the hydro scheme. We commissioned the outline and final designs from specialist consultants Renewables First, who worked closely with our civil engineering contractors, Land & Water and the turbine manufacturer Spaans Babcock.

How much electricity will it generate?

We estimate that the scheme will generate, on average, 320 MWh of electricity a year. This figure comes from modelling the performance of the system using 16 years of historic data on the height and flow of the river Thames at Caversham weir. We took into account times when the scheme would have had to stop generating because of flood or drought.

To put this in context, that’s enough to supply all the electricity for about 90 households consuming the UK average of 3,800 kWh a year.

Has the project changed the look of the weir?

The hydro scheme is a small new feature of the existing large man-made construction that is Caversham Weir. Much of the concrete work is underwater. The small turbine house was built using block construction. A mural is painted on the North and West walls, and ‘climate stripes’ on the East wall. This makes the turbine house an interesting addition to the riverside, not just a functional building.

How will we protect wildlife?

Obstructions like weirs prevent fish and eels from moving up a river, and thus disrupt their life cycle. Fish passes help, but the current fish pass next to Caversham weir is too steep for most fish. Reading Hydro volunteers therefore made a new, more natural-style fish pass through View Island. This will help a range of fish and also eels move up stream, as well as creating habitats for fish to spawn and wild flowers to grow.

Reading Hydro volunteers also cleared a lot of rubbish from View Island, which will boost the natural ecosystem. Bird- and bat-boxes have been installed to actively encourage more species to stay on the island.

Why’s hydro a good way to generate electricity?

Hydro schemes emit no CO2 or other greenhouse gases when they are operating. Emissions associated with the manufacture and installation of a hydro scheme are very small (averaged over the lifetime of a scheme). 

This means that greenhouse gas emissions are reduced when a new hydro scheme displaces electricity generated from fossil fuels.

Using UK government figures, we estimate that Reading Hydro will save about 5,600 tonnes of CO2 during its 40-year operating life.

Reading Hydro will also help the national electricity supply. Our modelling predicts that the output will be highest in winter and spring. This is when the demand for electricity is highest in the UK. And the hydro scheme will keep generating at night, when solar PV schemes stop.

Who else is involved in the project?

We’ve worked closely with Reading Borough Council, the Environment Agency and SSEN, who agreed the necessary permissions for us to build and operate the scheme. We’ve had strong links with the Reading Sustainability Centre from the start, as well as with Transition Town Reading and the Greater Reading Environment Network. We’ve had help from Low Carbon Hub and we’re a member of Community Energy England and Co-operatives UK.

How will we involve everyone in Reading?

We’ve had fantastic support from the people of Reading. Before COVID restrictions, we regularly took part in local events to talk to people and encourage them to become members.  We were thrilled by the local media interest in our share offers. Local people who bought shares sent messages of encouragement as well as their money. The hydro site is close to the town centre and many people walk past every day and get interested – some people who became active site volunteers found us by being passers-by!

 Our open data on this website allows people to follow the performance of the system for themselves. We hope soon to offer presentations to members, schools, community groups, local businesses and others.

We’re also active on Facebook, X (Twitter) and Instagram – come follow us and keep updated with our project!

Is the hydro scheme going to harm fish or newts?

We’re a group of local people committed to our community and to our environment. Because of that we’re taking extra care in how we design the hydro project to protect wildlife.

The natural fish pass we created will enhance biodiversity, by allowing fish and eels to travel upstream more easily. It will also provide places for fish to spawn and damp areas for wildflowers to grow. Our habitat surveys have established that there are currently no great crested newts on View Island at the moment. We hope that the shallow ponds associated with the fish pass will encourage them to take up residence.

What’s special about local energy?

Local renewable energy projects are great for several reasons. They make use of free local natural resources, and help to reduce our area’s carbon emissions and combat climate change.

There’s a high demand for electricity in Reading. By generating some of this electricity close to where it is used, we help cut losses in transmission and distribution – which currently waste seven percent of UK generation.

Local projects inspire people by making renewable energy a local, tangible option – not distant or even offshore. They’re a fantastic educational tool, showing  sustainability in action right on our doorstep.

Where can I find Reading Hydro’s accounts and society rules?

All this information is available here on our website, or via the Mutuals Register of the FCA here.

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