Buckinghamshire Energy Strategy. Westmill wind and solar cooperative site visit report

Transcription

1 Buckinghamshire Energy Strategy Westmill wind and solar cooperative site visit report i

2 Contents This document... 1 Westmill Wind... 2 Project background... 2 Details of the turbines and their outputs... 2 Shareholding and project capitalisation... 3 Community involvement... 3 Observations from the visit... 4 Westmill Solar... 5 Project background... 5 Details of the solar panels and their output Shareholding and project capitalisation... 6 Community involvement... 6 Observations from the visit... 6 Conclusions... 6 Appendix 1 Mark Luntly Workshop Slies on the Westmill Wind and Solar projects... 7 ii

3 This document The Councils of Buckinghamshire in partnership with the local LEP have been sponsoring the development of an Energy Strategy for the county. The approach that has been agreed is to focus the Buckinghamshire Energy Strategy on delivering economic and social benefits to the people of the county from the development of energy projects. This makes the approach technology agnostic and creates the opportunity for local people and community groups to become involved in the development of energy projects and thus to drive maximum local benefit from them. As part of the work to develop the Energy Strategy for Buckinghamshire, the initial workshop included the presentation of a case study by Mark Luntley on the Westmill Wind and Westmill Solar projects, which are large renewable community energy projects that have been developed close to Buckinghamshire. Such was the interest generated by this presentation that the workshop participants were invited to a site visit to see the scheme and to find out more about it and the history of the project. At the same time, this visit gave the opportunity to get close to two key energy technologies to find out what is like to be close to them in terms of noise, visual impact and other potential issues. This short report describes the outcomes from this visit. Mark Luntley s original workshop slides are appended to this report as they give more detail on the project than is covered in this report. 1

4 Westmill Wind Project background Seventeen years ago Adam Twine decided to erect some wind turbines on his is farm for reasons of environmental benefit. Initially the project was confounded by the slowness of the planning process not keeping pace with the development of new turbines with smaller turbines becoming obsolete within the timeframe of the planning process. Eventually the project (then based on 750kW machines) was offered to National Power, who had been supportive up to that point. Sadly, National Power withdrew at this point. However, this cased Adam to turn the project into a community led scheme and to this end a Cooperative was established in 2004, the prospectus was launched in 2005 and the share offer closed in Energy4All provided support throughout this process. (For more details see ) After then the project had obtained planning permission for five 1.5MW Siemens turbines (larger in size and number compared to the original scheme) and generation began in While there were objections to the planning application, these were notably fewer and less vociferous than for the original smaller but developer led scheme. With less than 1% of the land taken for the wind turbines, the farm remains in full production. Details of the turbines and their outputs The 5 turbines are 50m high up to the nacelle which houses the generator and gearbox. Each of the three blades are 30m long. This makes the height from the ground to the top of the blades 80m. The gearbox is 10 tonnes and is in two sections. It required a suitable crane for installation. Each took 2 days to install. Each turbine has an access track and an area of hard standing around it. This was required for delivery and erection of the turbine and is required to facilitate repair and service. For instance, if a turbine blade needs to be changed this will require the use of a crane. This dead area is 1% of the 185ha site and the access roads are shared with the solar farm. The wind turbine cuts out under high wind speed (25 m/s or more) and the blades are feathered to protect the machine. This happens only 3-4 times in a year. Different machine and blade combinations can operate differently under different wind regimes. The turbines and blades on the Westmill site are designed such that generation kicks in at 3 m/s and 2

5 increases to 12 m/s. At higher wind speeds the generation starts to flatten out. Blade angles alter automatically to optimise energy yield and the turbine automatically align with the direction of the wind. Topography and even soil type can affect the laminar flow of wind and thus the effective wind speed. The turbines are rated at 1.3 MW each, but output is dictated by wind speed. As will all wind projects, the availability factor (the amount of time that the generator operates at full output) is around 35% on an annual basis. This is taken into account in the economic analysis. Production varies each day of the month and from year to year. Last year the best month for wind generation was May! Wind speed is cyclical over a long period. Therefore predictions are only based on long term data The Westill turbines produce 12 GWh of electricity (12 million units) per year, which using Ofgem s latest estimations of electricity consumption is enough to power over 3,600 homes. The electricity from the turbines is fed to a sub-station is located at one end of the line of turbines and from here into the local grid. The total cost of installing the project was 8m. The simple payback is around 8 to 10 years. The machines have all been reliable, with no unplanned outages. At decommissioning the turbines can be sold and parts and materials can be re-used. We just don t know at this this stage technology changes with regards to separating and reusing materials. Shareholding and project capitalisation The public were offered shares and within 3 months 3.6 million was raised by this route. They have 2,400 local shareholders with an average investment of 2,000. Interest is payable each year. Each shareholder has one vote, irrespective of the investment made. Finance was 50/50 with the 3.6 million from the shareholders matched with bank loans. Once the bank loan is paid off then the return to investors will increase, with the full term return in the order of 8-10%. The collection of money was advertised and local meetings were held. Preference for investment was provided to local people. This tends to include people within a 50 mile radius. Community involvement While there was some local opposition to this community scheme, however, this has completely evaporated now the turbines are built. This confirms all other research in this area where the initial pre-build opposition makes way for local support once the turbines are operating. 3

6 A local community Sustainable Energy Trust takes income from the project to support sustainable energy locally. This (in addition to financial return to shareholders) gives local benefits back to the community. There have been 7,000 visitors to the site since it has been built. Organisations like Renewable UK use it as part of seminars. Local people provide support and host visits and provide a community spirit. Observations from the visit Noise. Despite standing next to the turbines, it was noticeable how quite they were in operation relative to expectations. Most noise came from the blade swish with only a low hum from the gearbox. While these noise elements will increase at higher wind speed, so will the general wind noise background. Bird strike. There was no physical evidence of bird strike on or around the turbines and this has not been thought to be a problem in this location. General impressions. By any standards, this is a large wind development and yet there was a general feeling that the turbines fitted within the landscape 4

7 Westmill Solar Project background The Westmill Solar Cooperative is a separate organisation to Westmill wind, but they are co-located. The solar project was developed on the back of the success of the wind project and in response to the (then) highly lucrative government feed in tariff for large solar arrays. For more details see Unlike the wind project, the solar scheme was conceived and developed quickly, befitting from the experience of the wind project, the physical infrastructure that had been put in place for the wind project and the grid connection. These all reduced the cost of the project. Details of the solar panels and their output. The project occupies 13 ha and has a peak output of 5 MW. The system comprises 21,620 panels in total. The panel themselves occupy 3.6 ha with wide corridors between panels to avoid shading. 1.2 kw of electricity is produced per square meter on a sunny day. The panels took 3 months to install onto lightweight framing set into the ground. It is a fixed installation 30 degrees due South. Only would be 20% extra efficiency if they move to track the sun, but the cost of achieving this does not justify the investment. Cleaning is not an issue. There is a protective coating and rainwater cleans off any dirt. Sheep grazing (in the winter) is used around the panels, helps to keep soil fertile and it is a nature reserve with wild flowers in the summer. While wind produces AC current at high voltage which can be transported straight to the mains, solar produces DC current at low voltage. This DC current needs to be converted to AC and boosted to a voltage that can be fed into the local grid. This is done by inverters and transformers housed in cabinets in some of the corridors. The system receive a 6 monthly service by Siemens staff. As cables are valuable and they had some issues with them being stolen, so there is a security system in place. The 5MW of cells produce 4.8 GW hours per year (4.8 million units), which using Ofgem s latest figures can supply for 1,400 homes. 50,000 has been invested to cover the cost of decommissioning. German company Abacus installed the panels, the panel are from Taiwan and the British produced the frames and transformer. The performance of solar panels are known to decline with age due to 5

8 the effects of UV radiation. The suppliers of the panels used guarantee a 90% output for 10 years and 80% output for 20 years. Shareholding and project capitalisation The need to act quickly to capture the enhanced support payment led to a non-ideal funding mechanism. Against a total capital cost for the scheme of 13m, a redeemable 15 million bond had to be raised as the route to quick money. Over the next year, 6m was raised from 1650 shareholders and a further 9 million from Lancaster Pension Fund in the form of a 12y loan. This was used to redeem the bond and return ownership to the Westmill Solar Cooperative. As with the wind project, the overall return to shareholders will be in the range 8 to 10%. Community involvement The project also supports the local Community alongside the Westmill wind project. Observations from the visit Noise. The most startling thing from the visit is just how noise comes from the inverter/transformer cabinets during periods of high electrical output. This was far in excess of the noise coming from the wind turbines, where noise is thought to be an issue. Land use. The land take per kw of generation is significantly higher with solar, with apparently fewer opportunities for the co-use of the land. General impressions. This is a large solar array which can be seen in the landscape, with sun glare increasing the visual impact of the scheme. However, colocating wind and solar seems to be a good option for many reasons in areas where higher wind speeds can support wind energy generation. Conclusions Attendees valued this visit and the opportunity to see large scale energy generation first hand. This created the opportunity to form better views about the impact of these technologies in operation. The community aspect of the project was also valuable. The speed of share uptake and the amount of money invested (especially by local people) indicates a good level of support for community projects and confirms the economic and social benefits that are available from energy projects. Demonstrating the potential of this approach is valuable as a reference when developing both the Buckinghamshire Energy Strategy and any changes to planning and other policies in support of this strategy. 6

9 Appendix 1 Mark Luntly Workshop Slies on the Westmill Wind and Solar projects 7

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