Introduction to this Page
The purpose of this page is to provide responses to many of the questions raised at the various fora that Teddington & Ham Hydro instigate and participate in. The team will continually update this page as new questions are asked and new information becomes available. Please note that a separate FAQ developed by the Environment Agency in September 2014 is also available here.
Please click on one of the sections below to review specific questions.
At the moment all the energy flowing over Teddington Weir is being wasted. The team believes that we, as a community, should be taking local action to make a contribution towards combating climate change and generating decentralised renewable energy. The weir allows for the possibility of generating clean, renewable energy.
Once built, the scheme will produce between 1.5-1.9GWh of electricity. This power will be exported into the grid, rather than directly power local homes, but in order to help understand the amount of power the scheme will produce, this is enough to power about 500-600 homes, or around 80% of the energy requirement of Richmond Borough’s Schools and reduce carbon emission by nearly 1,000 tonnes per year.
The scheme will be community owned with community investors benefiting from the financial benefits of energy generation through variable interest payments on their investments. In addition to this, 10% of profits will be gifted to the Teddington and Ham Hydro Foundation, which will seed other renewable and fuel poverty alleviating projects locally.
We are a volunteer group of local residents drawn from both sides of the river. While the project had its origins in Ham, it has since diversified its team such that the Managing Director is from Richmond, the Company Secretary from Twickenham, the Communications Director and our Health and Safety Officer are from Teddington, our Planning Manager from Kingston and our Technical Director from East Molesey. Ham residents will be pleased to know that they are still represented with two Ham residents on the Executive team!
The Environment Agency is the landlord of Teddington Weir and opened up the possibility of developing hydro power on it in April 2010. The team formed a non-profit organisation to bid for the exclusive rights to develop a project there. We were successful and have been working ever since to develop a workable design.
The scheme has MP Zac Goldsmith’s firm support. Our local councillors support us, and in principle all the local groups support the scheme except the Thames Anglers’ Conservancy.
These supporters include:
|Ham United Group||St. Mary’s University|
|The Richmond Society||Teddington Studios|
|Ham and Petersham Association||Project Dirt|
|Grey Court School||Kingston Environment Group|
|Kingston University||Naturesave Trust|
Yes. The Angling Trust objected to the location, on the basis that the proposed positioning of the scheme would be detrimental to fish migration. The Environment Agency agreed and Teddington & Ham Hydro were forced to move the scheme upstream to its current location.
This has the benefit of moving the scheme 17 metres upstream and therefore less visible from the nearest public point of access on the bridge near the Anglers’ pub.
The very simple answer is because the Environment agency will not allow a hydro scheme anywhere else on the weir. This decision is not with the remit of Teddington and Ham Hydro.
The position of the scheme on the weir is for environmental reasons. The section of weir adjacent to the Lensbury Club is the highest point in the weir pool and is the point fish will move towards as they look for a place to pass over the weir. The proposed turbines and new fish pass must be co-terminus. This is because the flow out of the turbines creates an attraction to fish. The fish pass is placed alongside to give fish the best chance to find it and use it to pass upstream. This arrangement is a licensing requirement based on design guidelines produced by EA for developers. The EA have decided this position for the hydropower scheme and not Teddington & Ham Hydro. The scheme will also be placed away from the main navigation route and will mean least disruption for river users during construction and operation of the scheme.
While we understand that certain members of the community would rather the scheme be built away from the river bank, there are several other good reasons in addition to environmental reasons to keep the proposed site.
The Scheme will be as far away from the main navigation channel as possible – Health and Safety issues have played a big part in the siting of the scheme.
The Environment Agency does not want to demolish any of the “Zig Zag” section of the weir as this could affect its overall integrity. The section chosen has the advantage of being able to be treated as a single, unitary section.
The amount of water flowing into the weir pool must be unchanged following the construction of the scheme. A larger amount of weir would need to be demolished if the scheme were sited elsewhere. Potentially, two non-adjacent sections of weir would need to be demolished which would increase risk, costs and disturbance during the construction process.
Building and maintaining the scheme will also be easier if it is close to land.
Finance and Investment
Teddington and Ham Hydro will be a community owned and run Energy Company. The current Government is seeking to incentivise community renewable energy with a number of incentives for individuals and communities and we aim to take advantage of these. As a result we think that our project will not only provide a compelling social return, it will also provide an attractive financial return.
For an investor, depending on their tax circumstances, investing for 20 years, the IRR (internal rate of return) will be around 8% per year averaged over the lifetime of their investment. The forecast revenue from the project will, after associated costs, pay back the capital costs within 10-11 years.
The lifetime of the asset is expected to be 40-50 year or more, so the directors feel that this is a good investment.
However, owing to the Government seeking to encourage individuals and communities to invest in decentralised renewable energy, tax breaks are available that will reduce this payback period for individual investors. The Directors anticipate that investors will have been paid back all of their capital within 8-10 years. This will be derived from a mixture of tax relief from HMRC, interest payments and capital return. Additionally, post this period, investors will still hold a stake in the project and enjoy interest payment on this remaining stake.
The revenue will come from two areas, both related to the amount of electricity that the project generates. The first source, and accounting for around three quarters of forecast revenue, is from the Feed-in-Tariff. This is currently set at 15.2p per kWh and is linked to inflation and should grow over time. The second source is from selling the electricity either to the grid or to an end user. The price that we sell the electricity for is variable and dependent on market conditions. We are currently expecting this to be 6p per kWh.
We have assumed that inflation will be 2.5% over the investment period (this is the mid point of the bank of England’s target) and electricity prices grow by 4%.
The cost to build the scheme is forecast to be £3.7m. However, we are budgeting for a 10% contingency and will also need to fund our VAT so will be raising £5m.
It sounds like a lot, but the demographic of the Borough of Richmond is such that there is a significant populous with capital available for investment. We’d highlight that Dingwall, a small farming community in Scotland, raised nearly £900,000 from a population of just over 5,000 people to finance a community owned wind turbine. Furthermore, community energy is something that the government are targeting and so tax breaks are available for investing in community energy schemes.
We will aim to pay investors a fair financial return. From the second year, we will aim to pay a dividend of 3.5%. Given the inflation linking of our revenues and the relatively small and fixed cost base, we expect our profits and therefore interest payment to be able to grow over time. In addition, depending on your tax circumstances, there will be tax benefits. We had a pioneer share offer earlier this year and there its lots of detail in the Share Offer which can be found on the investment tab of this website. For example, there are four scenarios at the back of this document.
Teddington and Ham Hydro is a long term investment and not like investing in either a bank account or shares on the stock market. You should expect to tie your money up for at least 5 years, preferably longer. Shares cannot be traded on any stock exchange and can only be bought back by Teddington and Ham Hydro. No capital will be returned within the first four years. The Directors plan to refinance the scheme with bank debt at year 4-5, such that investors may withdraw up to 50% of their capital. Thereafter, around 3% of capital will be available to be returned to investors each year, at the discretion of the Directors. You should not invest in Teddington and Ham Hydro if you expect to need the money over the medium term. You should not invest any money that you are not willing to lose.
We are running a main share offer and have already ran a pioneer share offer. The first carries more risk than the second and is compensated by a higher tax relief. If you invest in the main round capital raise, available as soon as we obtain planning permission, depending upon your tax circumstances, you will be able to reclaim 30% of your original investment from HMRC when you complete your tax return.
Yes. Depending on your tax circumstances, you could have your capital returned by 8-10 years. Post this period, investors will still retain a valuable investment that will pay a reasonable and growing interest rate (depending on the performance of the project). Investing in Teddington and Ham Hydro will provide both an attractive social and financial return.
Our pioneer share offer Share Offer is published on the investment pages of this website. An updated Share Offer for the main share offer will be published shortly.
As part of the project Teddington and Ham Hydro will set up a foundation to fund other renewable and fuel poverty alleviating projects. 10% of all profits each year will be gifted to this Foundation. This will operate on an arm’s length basis to Teddington and Ham Hydro and provide both funds and expertise to innovative community projects. The main aim is to help other projects have a slightly easier path than we had!
Not according to our noise consultants – they have produced several reports to show that with the acoustic insulation they recommend, the project will not generate any more noise than that currently produced by the weir at various key sites.
This depends on tides, but if the tide is such that there is sufficient water running over the weir, then turbines will run at night. However, our noise consultants have demonstrated that the noise levels at key receptor points are no noisier than the normal background noise, both day and night.
Maps have been prepared by highly skilled specialists. Additionally, the data from the models have been cross-checked with the actual noise produced by the turbines at Romney weir.
In the unlikely event that the scheme, once operational, proves to be noisier than the permitted levels, Richmond Council will require us to shut down the turbines.
The allowable noise levels vary depending on where you are standing. However, in most cases the noise levels are not allowed to be above 50-60 dB. We show the permitted level in the table opposite, with the expected levels of noise from the turbines. In all cases, the noise from the turbines is lower than that of the allowed level. We also provide an infographic below on what these permitted levels of noise actually mean in real life.
In our noise assessments, we have represented the noise (both back ground and that of the turbines) using the dB scale. The infographic below helps explain what these measurements actually mean!
On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30dB. See below for some common sounds and their decibel ratings.
You know from your own experience that distance affects the intensity of sound – if you are far away, the power is greatly diminished. All of the ratings above are taken while standing near the sound.
Any sound above 85 dB can cause hearing loss, and the loss is related both to the power of the sound as well as the length of exposure. You know that you are listening to an 85 dB sound if you have to raise your voice to be heard by somebody else. Eight hours of 90 dB sound can cause damage to your ears; any exposure to 140 dB sound causes immediate damage (and causes actual pain).
|Location||Criterion||Required Level (dB)||Predicted Scheme Noise Lelve (dB)||Noise Level Difference (dB)||Compliant|
|Dwellings Along Burnell Avenue (MP4)||BS 4142
|BS 8233 / WHO
|Lensbury Club Garden: Downstream||BS 4142
|BS 8233 / WHO
|Lensbury Club Garden: Upstream||BS 4142
|BS 8233 / WHO
|Rear Façade of the Lensbury Club Hotel||BS 4142
|BS 8233 / WHO
|1 Including 5 dB penalty (as per BS 4142)
2 No Penalty included (no penalty in BS 8233 or WHO ‘Guidelines for Community Noise’)
3 30 dB attenuation allowed for an open window as per LBRuT NTS
4 12 dB attenuation allowed for an open window as per LBRuT NTS
In all of these places, the noise from the turbines is less than that of normal conversation. Indeed, at Burnell avenues it is only fractionally above a whisper. The noise from the turbines will certainly be less than that of the weir unless you are standing right next to them.
The nearest residential dwelling to the turbines will be on Burnell Avenue in Ham. The stretch of river on the Middlesex side closest to the proposed site of the turbines is not accessible by the general public and only by members, guests and staff of the Lensbury Club. The Lensbury Club is a vital stakeholder in the project and we want to make sure that it is not adversely affected by our scheme. On the contrary, we hope that they can make our scheme an attraction for their guests. We have taken this on board when we have conducted our noise assessment surveys.
Yes. They are on our website and freely downloadable from the Council planning portal
Stood 10 metres from the scheme in any direction, the noise from our turbines will be less than 50dB. As the previous infographic shows, this is significantly less than normal conversation. At this distance, the noise from our turbines is likely to be drowned out by the noise from the weir.
Noise charts can be found within our detailed noise report. Please note that we are currently developing further noise maps of what the current situation is at the weir so that our models can be compared against this benchmark.
Archimedean Screws have been used for 1,000s of years but until recently their purpose has always been to raise water. By reverse engineering the screws and installing them on a river it is possible to utilise the energy generated by the flow of the river. This is amplified when sited on a weir as the drop in water level can also be exploited.
The projected yield of the scheme is based on modelling carried out using flow and head data from the last 40 years. A detailed model of the yield based on the data collected every 15 minutes during the year 2010 has been produced by Teddington & Ham Hydro and is available on the Teddington & Ham Hydro website. A further modelling process has been carried out using an alternative methodology; both methodologies have produced very similar results.
The technology used is somewhat constrained by the requirement to be fish friendly. While other technologies may be less visually imposing or produce modestly more power, the preservation of the ecology of the weir pool and the river generally is vitally import to the Environment Agency. This is a view shared by Teddington and Ham Hydro. This closes off a number of options and essentially leaves only one core technology – Archimedean Screws.
The two schemes are not the same: Romney is not tidal, so it doesn’t have the same constraints. Romney doesn’t have to be 1m higher for meeting a possible flood event because it does not have the same variability due to tides. Additionally, that scheme was not required to have an additional sluice gate as part of its structure. With respect to its overall height, the Romney scheme has the switch gear in a building adjacent to, rather than on top of, the scheme. The similarity is that Romney has the same size turbines, although it has two instead of the three planned at Teddington Weir, and the scheme has a fish and eel pass.
The pivoting technology used at Romney is a relatively new concept and only commercialized by one player in the hydro electricity market. It has not been proven to increase the ability to operate the turbines over a wider range of river level conditions. The design used at Romney will not allow the turbines to be ‘swung out of the way’ to allow full uninterrupted flow in the event of flood conditions. The Teddington & Ham Hydro team have looked at the pivot idea and kept an open mind but the increased cost and impacts on design do not justify installation at this time.
Moreover, the technology is still new and relatively unproven – there is only one scheme operating with it in the UK currently.
Health and Safety
Safety of river users will not be reduced after the construction of the scheme. In fact, its construction will allow the opportunity to assess the current health and safety procedures at the site and improve them, where necessary. Significant work has been done with the River Users Group to assess the health and safety impacts of the scheme and flow analysis has showed that the scheme will not have any significant impact on the flow profile of the river. We are working closely with the RNLI and they will be advising on the detailed design of the scheme’s upstream screens once we have planning permission.
Health and safety has been built into the core of the design and the positioning of the scheme from day one. Indeed this is a key reason that the scheme is where it is – it is as far away from the main navigation channel as possible.
The structure will be on EA property, and will have to adhere to the rigorous standards that the EA applies to all its properties across the country. As we move to the technical design and construction phase, these standards will be further clarified.
The Environment Agency is the weir owner and will carry out Public Safety Risk Assessments to ensure the scheme has done all it can on the safety front. At present, Teddington Weir represents a danger to unauthorised access by any river user, due to the moving machinery and large flows through gates. The Agency already maintains protective barriers upstream of the weir to prevent river users straying into the danger area, there are also signs providing warnings. The Agency believes that the addition of hydropower on the weir will not increase the risk to the public. The construction phase will also be regulated to manage safety risks associated with constructions sites.
Safety is considered in the hydropower scheme design and has been discussed throughout the design process between the Agency and Teddington and Ham Hydro. In the finished construction, we will be required to screen the turbines and restrict access to all moving parts. Moreover, designers have a legal obligation to consider safety in their design to ensure a structure can be constructed and operated in a safe manner.
The weir is an inherently dangerous structure and there are currently floating booms upstream of the weir to prevent boats and people from getting close to it. We will retain or supplement those booms to retain or improve upon the same protection. We will increase the existing signage to draw attention to this provision. In addition, the turbines are screened with 300mm-bar screens. Any river user unfortunate enough to have passed these signs and booms will be stopped by these screens and able to climb up the structure using a ladder. These users would have otherwise have been pulled over the weir had the scheme not been there.
Certain constraints have been placed on us by the Environment Agency in its capacity as the statutory consultee with regard to the location and height of the design as well as the technology to be used. For instance, for safety purposes the walkway on which the electrical equipment sits must be above the 100-year (+climate change impact) flood event level. Also, the scheme must enable fish to find their way to the new fish pass – hence the change to our previous positioning of the scheme.
Teddington Weir is a man-made structure which has undergone several evolutions over time. In our designs we have sought to capture and improve upon the essence of the weir. We expect that, with time, people will look as fondly on our hydro scheme as they do on the wind and water mills in Turner’s paintings.
The present structure of the section of the weir that our scheme would replace is of comparatively recent date: its reconstruction was completed in 1992.
Construction and Operational Risks
Teddington & Ham Hydro. The scheme will employ sufficient staff to cover 24 hr / 7 days week, and work with lock keepers, EA and London Port authority.
The turbines are guaranteed to operate for 40 years; we would hope that the scheme will operate for many more years.
Our flood risk assessment has been verified by the Environment Agency and it shows that our scheme will have negligible effect on the risk of flooding. Should flooding conditions occur, our scheme will also have negligible effect on the extent of flooding that will occur compared with the extent had the scheme not been there in the first place.
This document is freely available to download from this website within the technical documents repository
While the construction phase of the project will last for around 6 months,the duration of piling will be only be for around one week. All construction inherently has a degree of noise, however we will be working with a Contractor within the considerate contractors scheme, whose work and hours are regulated by the Council. All piling will take place during normal working hours.
Much depends on the timing of the planning decision. However, the build process will take around 6 months, of which the piling process will be less than a month. We will make sure that we do not build during higher flood risk periods.
The electricity from our scheme will not directly power 600 homes. This figures is an equivalent amount of energy. Our energy will be sold into the electricity grid and demand that would have otherwise been met by fossil fuels, will now be met by renewable energy. Depending on your energy supplier, you will have the opportunity to ‘choose’ the source of your electricity including specifically this scheme.
Records on the weir first began in 1883 so there is a wealth of historical data relating to flow and tidal conditions. We have constructed our output models using data from last 40 years. Detailed models show that there is sufficient flow in the river to make the scheme economically viable, even taking into consideration the tidal variations involved.
We will take out insurance to cover material damage, mechanical breakdown, loss of revenue and public liability. In addition, the manufacturer provides a performance guarantee, as well as the 40-year guarantee on the turbines themselves mentioned above.
This will depend on when we receive planning permission from Richmond Council, but we aim to start exporting electricity in late 2015.
We have an new planning application that is currently being consulted on and we expect to obtain a hearing in February 2015.
Look on our website on a regular basis, and ask to be added to our mailing list. We are also on Twitter, Facebook and LinkedIn.
This is not something that we can have any influence over. However, its distance from the turbines will mean that it will experience negligible noise disturbance from our scheme, should the development get the go ahead.
This is not something that we can have any influence over. However, its distance from the turbines will mean that it will experience negligible noise disturbance from our scheme, should the development get the go ahead.
We have commissioned reports assessing the potential areas of concern in the weir pool and its immediate surroundings which show that the operation of the scheme under EA-imposed operating conditions will not have a detrimental impact on the local environment.
A flood risk assessment has been carried out by our consultants which shows that there will be a “negligible” impact on flood risk.
The Archimedean turbine allows fish to pass through it without being damaged. Please refer to http://www.fishtek.co.uk/hydropowerresearch.html for further details.
In addition, our scheme includes a new fish pass, 3.6m in diameter, to replace the two existing 1m-wide ones. This new fish pass will include multiple gradients to enable the migration of a variety of species. This will be a significant improvement on the current situation for fish migration. In addition, we will install an eel pass.
We have taken the liberty of extracting a copy of a letter written to the Richmond and Twickenham Times from Rob Gray, Chair of Tidal Thames HAP Working Group. We think this provides a good summary of the key environmental issues around our proposed scheme. He has also posted a more detailed response on the planning portal in support of our application. This was unsolicited.
“In general, the ecology of the upper tidal Thames is not very well understood by anyone. Given the current poor state of understanding, the requests for an EIA (Environmental Impact Assessment) to show definitively the impacts of this scheme do not seem to be reasonable or realistic. Any EIA is bound to be fairly inconclusive and raise more questions than it resolves.
The scheme is proposing to improve upon the existing fish and eel passes on the weir. This is clearly a good thing for the river ecology.
The screw design has been sanctioned by the EA and that it will also incorporate rubber bumpers on the screw blades. There may be a residual risk to fish but how significant this is compared to the many other risks they run from boat engines, fish hooks, cormorants and other fish for example?
There have also been concerns expressed about the potential impact of the scheme upon gravels local to the weir. As noted above, there is so little information available on (a) river bed habitats and (b) their importance to fish populations, not to mention (c) the potential impact of the scheme upon the flow regime across the weir and (d) its consequent impact on this local ecological feature. There are far too many unknowns and variables to reasonably expect them to be evaluated in advance. No compelling evidence has been produced that indicates either that (a) the scheme will impact negatively on these local habitats or (b) that these habitats are critical to the value of the tidal Thames ecology overall.
One aspect of the scheme that has not been mentioned by others is its impact upon bats. Bats are a priority species under local and national plans and this reach of the Thames is known to be an important feeding habitat for them. The scheme is pledged to review and update the lighting of the Teddington Weir crossing and reduce its impact upon the night time bat feeding corridor.
- The scheme would provide overarching benefits to the environment and community as a high profile example of renewable energy with profits invested for local improvements
- The scheme would provide two significant benefits for the tidal Thames ecology in the form of new fish and eel passes as well as more bat friendly lighting
- The issue of fish damage from the screws may need to be bottomed out. However I note that the EA appears to be satisfied on this issue – and the risks to fish may well not be significant in comparison to all the other perils they endure in the tidal Thames
- The issue of impacts on local habitats is near impossible to prove at this stage – however there is no clear evidence that any impacts are likely to be significant to local habitat, still less to the overall habitat value of the upper tidal Thames
- There is the potential for profits from the scheme to support much needed investigation into the actual ecological value of this stretch of the river and how this can be optimised. In my view this would be an appropriate and hugely valuable benefit for this reach that has been largely beyond the capacity of existing networks”