Technical Brochure No.22

IEA OECD renewable energy

Delabole , UK

Summary showed that many of the people living in the area near the site who Highlights Ten wind turbines are installed on a disapproved or were unsure of the ▼ Generates 10-12 GWh of farm in , in the south-west concept of a wind farm before electricity annually of , with a total rated construction had changed their ▼ Reduces emissions of capacity of 4 MW. The turbines minds in favour of the concept after greenhouse gases produce about 10-12 GWh annually. 6 months of operation. The wind This was the first wind farm farm has helped the local economy ▼ Provides local employment planning application to be filed in by providing jobs and attracting the UK. Public attitude surveys large numbers of visitors.

Delabole wind farm.

WIND ENERGY Project Background second after the wind farm had been turbine and fed directly into the grid operating for six months. The through an existing substation Wind energy has been used for results of the first survey showed 300 m away from the closest centuries to grind corn, pump water that only 17% approved of the turbine. All cabling is underground. and provide simple mechanical concept of a wind farm, 32% A small building for the switchgear power. The modern disapproved and 51% were not sure. is located next to the substation. generator has now been proved as The survey conducted six months one of the most cost-effective means after the wind farm had begun Generation starts at a wind speed of 4 of exploiting renewable energy. For operating showed that at this stage m/s and reaches maximum output at the UK, which has the largest wind 85% approved, 4% disapproved and 12.5 m/s, where it is governed by resource in Europe, wind energy 11% were not sure. pitch control of the blades. At wind represents one of the most promising speeds in excess of 25 m/s the of the renewable energy technologies. The Project turbines automatically cut out, but have safety tolerance in excess of 57 The wind farm was developed by a Ten Windane-34 generators m/s. Each turbine is independently Cornish farmer who wanted to with a total rated capacity of 4 MW controlled by its own computers, but exploit to provide a are installed at Delabole in linked to a central monitoring system. source of income different from his Cornwall. Each turbine has a normal agricultural interests. His 34.8 m diameter three-bladed rotor Foundations work started at the end of aim was to generate electricity and mounted on a tower at a hub height August 1991. The turbines were sell it to the National Grid. Because of 32 m. The turbines are spaced transported to Delabole using four of the sensitive nature of wind about 270 m apart, to minimise lorries per turbine. Using a 90 tonne farms a survey was commissioned, energy loss due to turbulence, and tracklaying crane and 60 tonne all- in collaboration with the UK each stands on a base of reinforced terrain wheeled crane, all ten turbines government, to establish people’s concrete. The three phase induction were erected without roads in just five attitudes towards wind farms. Two generator synchronises with the grid weeks and the last one was connected surveys were carried out: one before at 50 Hz. The power is generated at to the grid in December 1991. the wind farm was built and the 690 V, transformed to 11 kV at each This was the first wind farm Each turbine was erected on a base of reinforced concrete. application to be filed in the UK and, understandably, the Planning Authority was cautious. Environmental Impact Assessments had just been introduced and it was mutually agreed that one would be needed. The Authority’s main concerns were visual intrusion, noise and the effect on television reception. An agreement was negotiated on the basis that no turbine was to be closer than 350 m to any dwelling, the noise level at the nearest dwelling was not to exceed certain agreed limits and all blades were to rotate the same way. The time taken from the initial application to the final agreement was two years. Turbine parts were transported using all-terrain vehicles, so no road-building was necessary.

This project initially benefitted Performance Economics from the Non-Fossil Fuel Obligation (NFFO), introduced in Despite one of the lowest average The total capital cost of the project 1990 by the UK government as part annual wind speeds in the last was £3.4 million ie £850/kW (where of the privatisation of the UK 20 years, the wind farm produced £ is the UK ) at 1991 electricity supply industry. The over 10 GWh in its first year of prices. This included the turbines, NFFO obliges the twelve regional operation and achieved its financial erection, all civil and electrical electricity companies in England forecast. Energy production rose to works, grid connection and project and Wales to secure a specified 11.7 GWh for the period March development costs. capacity of their electricity supply 1993 to April 1994. This from non-fossil fuel sources, such corresponded to an average load Operation and maintenance are as and renewable factor of 33.7%. The availability of linked with a manufacturer’s five- energy. Renewable energy from the machines was better than year warranty which includes commercially-developed forecast, achieving a level of 97%. availability and performance technologies can receive a premium However, subsequently availability guarantees. Total annual operating price for the power they generate, is averaging 99%. cost (including all insurance, rents paid for by a levy on sales of and management charges, but not electricity to final customers. The main operational difficulty has finance charges) is about been a lightning strike (a very rare £0.015/kWh. The NFFO contract ended in occurrence), two weeks after start- December 1998 by which time all up. The blades on one turbine were Of the total finance, 40% was equity loan and equity finance had been damaged, but there was no damage subscribed by the landowners, repaid. Production is now being to the generator or computers. The National Power and South Western sold on the open market through damage was soon rectified and Electricity plc, and 60% was a loan Unit E with a small green production losses were covered by provided by County NatWest Ltd premium. insurance. (now NatWest Markets).

Technical Brochure No.22 Host Organisation Windelectric Management Ltd Deli, Delabole Cornwall PL33 9BZ Contact: Mr P Edwards Tel: +44 1840 213377

Equipment Supplier VESTAS Smed Hansens Vej 27 DK-6940 Lem Denmark Tel: +45 97 34 11 88 Fax: +45 97 34 14 84

Information Organisation ETSU Harwell Oxfordshire OX11 0RA United Kingdom Contact: Dr H G Parkinson Tel: +44 1235 433462 Fax: +44 1235 433355

Please write to the address below if you require more information. IEA OECD renewable energy

CADDET Centre for Renewable Energy ETSU, 168 Harwell, Didcot Oxfordshire OX11 0RA United Kingdom Tel: +44 1235 432719 Fax: +44 1235 433595 E-mail: [email protected]

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UK 94 009 First printed 1995 Updated 2000