Draughtproofing & insulation

Reading Hydro was set up to provide local renewable energy, because this cuts climate heating, cuts air pollution, and cuts the control of big energy businesses.

But reducing the use of energy matters too. It brings these same benefits, and in addition cuts costs for the energy-user.

That’s why we’re delighted to see a new book published on ‘Draughtproofing and insulation’ by Tony Cowling, Founder director of Reading Hydro.

Draughtproofing is usually the most cost-effective way to reduce energy use in homes. But it’s often overlooked, even though it can be simple and cheap. Tony has championed this for many years through the Draughtbusters project which offers practical help to people struggling to pay their heating bills because their homes are cold and draughty. It’s great that this practical experience is now in print for everyone to use.

500 MWh generated

At 8:01 this morning, Reading Hydro had generated 500 megawatt hours (MWh) of hydro electricity! That’s enough to:

  • Drive 2 million miles in an electric car, taking you 80 times round the world (or if you’re more adventurous, 4 times to the moon and back!)1 or
  • Cook 77,000 roast dinners for a family (or about 140,000 if you have a vegetarian roast)2  or
  • Run all Reading’s streetlights for 57 winter nights.3

This renewable electricity has helped tackle climate heating. By cutting the need for gas-fired power generation, it has prevented about 200 tonnes of CO2 from going into the atmosphere.4

Many thanks to all the Reading Hydro investors and volunteers who have helped us reach this milestone, and to Thames Lido the main customer for our electricity.

(nb: one of our turbines may not be operating when you read this, because the river level upstream is close to where we must stop taking water. More rain needed!)

Power back on track

The sluice gate problem was sorted on August 8th. Our O&M team tracked it down to a tiny check-valve that was leaking. 

Generation returned to nearly normal levels, but then gradually declined. On August 12th our clearance team found the reason for this second problem: Canadian pondweed had collected on the trash screens, reducing the water flow to the turbines. Once the pondweed had been removed (see photo) the power returned to its normal level and has remained there. 

A big thank-you to everyone involved in sorting these problems.

But if somebody dumped all this Canadian pondweed in the river, PLEASE DON’T DO THIS AGAIN. Not only does it mess up our generation, it reduces river biodiversity by competing with native species for nutrients.

What’s up with Tony?

You may have noticed that turbine 1 (Tony) has generated only very briefly over the past two weeks. A contractor has established that we have an internal leak in the hydraulic system that controls the sluice gate, and is looking into what needs to be done. It’s enormously annoying, since we have plenty of head and flow for generation (which was not the case this time last year!). But it’s good that the automated control system cut in as soon as the problem occurred, so that our O&M team were immediately on the case.

Information boards

Take a walking tour of the Reading Hydro site, using the map below and our new information boards!

Board 1 gives a quick overview if you have only a few minutes to spare. Have a look at boards 5 and 3 to find out how the hydro plant works and how renewable energy helps tackle climate change. If you’re interested in nature then boards 2, 4 and 6 explain how we’ve helped fish, wildlife and plants.

We’re very grateful to the University of Reading for the design and production of the boards.

Recent rains have reduced our generation

Seasoned weather watchers cannot have failed to notice the recent heavy rain over the last few weeks.  River watchers will have also noticed the River Thames rushing under Reading Bridge towards Caversham Weir and onwards to Sonning and ultimately London and out to sea,   As you can see from the graph below the river flow has increased significantly since 18th December.

Flow at Reading Bridge

So how has this affected power generation at Reading Hydro?  Surely more water or faster moving water is a good thing to generate more power?  Well it’s not quite as simple as that.  As the rains fell across the Thames catchment the flow in the headwaters started to rise as the ground became saturated and the excess drained into the river and its tributaries.  Up and down the river lock keepers started opening their weirs to allow the water to drain through more easily and reduce the risk of localised flooding.

Water Levels

As a result the ‘head’ of water at Reading Hydro (difference in height between the river level upstream and downstream) started to reduce..  You can see this quite clearly in the graph above.  Our turbines turn due to the weight of water falling through the two screws from the upstream to the downstream.  When the head reduces the weight of water has less height to fall and consequently the power reduces.  Below 1m head the power loss decreases rapidly and even a few centimetres loss can see a drop of several kWs of power.

As you can see in the graph below the generation has declined greatly since the 20th December.   During this time our amazing Clearance team worked nearly every day to keep the screens clear and the water flowing through our turbines.  Of course the heavy rain washed a lot of debris down the river, some of which ended up on our screens particularly on the 21 December and over the Christmas and New Year breaks.  You can see the difference clearing the screens makes as the power generation jumps up, but then gradually declines as more debris builds up.

Power Generation kW

Sadly in the early hours of Sunday morning the increasing river flow and high downstream level reduced our head to below 0.5m at which point Turbine 2 shutdown while Turbine 1 was only generating 2kW.  The decision was taken to shutdown the system until levels improve and the all-important head rises to a sustained level.  With the weather forecast set to become drier for the next few days we are crossing our fingers that the river levels will change in our favour.

Reading Hydro highlighted at COP27

As part of efforts to raise climate change awareness as the intergovernmental COP27 meeting starts in Egypt this week, a leading environmental charity has recognised Reading Hydro as an ‘outstanding example’ of how community action can help combat the challenges of the climate crisis. Carbon Copy, the organisation behind the Running Out of Time Relay linking COP host cities Glasgow and Sharm El-Sheikh in the world’s longest continuous relay, identified 27 local projects which ‘formed the backbone’ of the relay route to celebrate and highlight how community action can make a real difference to global challenges like carbon emissions, including Reading Hydro via its Turbine House on Caversham Weir, Reading, UK

As an organisation, Reading Hydro is proud to have been part of this historic endeavor linking two crucial global summits on tackling climate change, as well having the collective efforts of our volunteers and investors being recognised in such an incredible way. We hope our local project can be an inspiration to others (and those at COP27) in how to turn good ideas and warm words into a positive and clean energy reality.

The full press release is here

Generation starts again

Great news – today (23rd October) the Environment Agency gave us permission to generate again, and both turbines were re-started just after noon!
The river flow at Thames Bridge had continued to run at about 5 cumecs (cubic meters per second) overnight, but surged above 10 cumecs by noon because of the heavy rain.
River conditions are still not stable, and we may have to shut down one or both turbines at short notice. But it’s so good to see them turning again.

We’re still working hard behind the scenes, maintaining the hydro equipment, developing our education programme, giving presentations to various groups, improving our internal processes. And we’d still welcome more volunteers – do look on our volunteers page for the roles we’d like to fill.

Reading Hydro & Running Out of Time Relay

With COP27 scheduled for next month, and nearly a year since COP26 in Glasgow, an extraordinary relay linking Glasgow to Sharm El-Sheik, Egypt, is being undertaken by hundreds of people across Europe and the Middle East. Known as the ‘Running Out of Time‘ (ROoT) relay, the Carbon Copy charity has brought together a community of people and projects to highlight the urgency of the climate change challenge, as well as the efforts being undertaken to try and mitigate the negative effects through positive community action.

This 7,767km relay operating 24/7 for 38 days will be passing through Reading on its journey towards Egypt, and Reading Hydro has been identified as a relay baton exchange point – we therefore invite you to support this unique effort and the teams carrying this baton towards COP27, and help deliver a message to world leaders that we can come together to tackle climate change and make a difference.

Key Info

Come support and cheer on our relay runners as they near the baton exchange point by our Turbine House. We have runners in Stages 143 & 144 of the relay, and are responsible as an organisation for getting the baton to the Turbine House on time!

If you’re joining us to support the runners, we will be cheering the team on on the other side of the river to keep the View Island pathway clear for the baton handover:

  • Date/Time: Friday 7th October, 14:40 – 15:10
  • Location: Hills Meadow pathway, by the skate ramps & opposite the Turbine House (What3Words: moral.gums.dunes)
  • Bring your best cheers and clapping with you! Our runners are expected to reach the Turbine House around 14:50

If you’d like to get more involved in the relay, there’s a couple of ways you can do this!

  • Join the stage: ROoT can host up to 25 runners per stage, so if you think you can run 6km in around 45 mins, then sign up and become part of the event!
  • Donate: You can donate and support our teams via the ROoT website – click on a runner and choose your level of donation

We’ll be posting updates of the relay on the day, so make sure you follow us on our social media to keep up with our teams!

You can also hear more about this relay from Austin, one of our runners, and Rick, Carbon Copy, in their interview with BBC Radio Berkshire.

Low flows for the River Thames at Reading is likely to continue

Coutersy of Callum Cromwell, Callum’s Night Photography

Reading Hydro volunteer Wilson Chan is a PhD student at Reading University, carrying out research on the impacts of climate change on UK water resources.  He’s applied his data modelling expertise to predict likely flow in the River Thames over the next few months. In a future blog he’ll update the data and also discuss the likely impact of climate change on the Thames flow. It’s great to have Wilson’s data modelling expertise to help us understand river flow better (even though the outlook is somewhat gloomy for the next few months….).

July 2022 has been confirmed the driest July on record for southern England.  The same month also saw a record-breaking heatwave with temperatures reaching 40°C for the first time. Precursors to the latest drought were a drier than average winter and spring 2022, and the driest winter-spring sequence since the 1970s. The flow of the River Thames at Reading has been declining since spring 2022 and high evaporation from the exceptionally hot and dry summer has exacerbated this decline. This low flow means that Reading Hydro hasn’t been able to generate electricity since June. So what is the outlook for the coming months?

To look at this, I followed the UKCEH Hydrological Outlook “Ensemble Streamflow Prediction” (ESP) technique based on historical climate to look at the likely river flows over the coming year. Details of the model and technique are in this paper, and the results are summarised in the graphs below.

The black line at the left of the upper graph is the actual flow of the Thames at Reading up to August 2022.  Each of the 56 grey lines that continue from August suggest the possible flow for the coming year, modelled by assuming that the rainfall and temperature will be identical to one of the past 56 years. The variation in weather from year to year leads to a large variation in predicted river flow, as anyone who has lived in Reading for a long time would expect. I have highlighted what would happen if we have a repeat of weather from particularly dry years (i.e. 1976, 2003 and 2011).  

It’s useful to see the wide range of plausible flow rates, but how do we know what flow is likely on a given future day?  The approach I used is to calculate the percentage of simulations falling in defined ‘bands’ of flow rate, which gives the probability that, based on past weather, the flow on a particular day next year will lie within this band, as shown in the lower graph.  Here, I’ve chosen thresholds relevant to Reading Hydro: a) 5.24 m/s, the hands-off flow below which we are never allowed to generate, b) 11.44 m/s, the minimum flow required for full generation and c) 37.9 m/s, the average flow of Thames at Reading.

The prediction isn’t very encouraging. It suggests that, without exceptionally high rainfall soon, there is a high likelihood that river flow will be below the level needed for the Reading Hydro turbines to re-start operation, until at least October 2022.