Arctic wind power

by E Peltola, J Kaas and E Aarnio, Kemijoki Oy, Finland

Implementing wind energy generation in remote arctic regions presents its own special problems. Since 1989 a Finnish project has been researching various aspects of wind energy production in Lapland. This article provides an update of that work, which has now reached successful commercial wind energy generation.

Early research

Interest in wind energy production in cold, icy regions and mountainous areas has been pursued in Finland since 1989. The early research programme included wind resource exploration in the mountainous areas of Lapland. Between 1989 and 1992, measurements were taken using small test turbines. In October 1993, a 220 kW wind turbine was set up on top of Pyhätunturi Fell to develop wind turbine technology in a cold, icy environment. Wind conditions in this area are favourable for wind energy production, with an annual mean wind speed of 7-8.5 m/s; the monthy average in winter exceeds 10 m/s.

Commercial development

This early research project has now developed towards the commercial production of wind power. The main topics in 1996-97 were the production, development and commercialisation of blade heating systems; the development of operation and maintenance practices for arctic wind power plants; preparations for new wind farms; and various network connection and energy system studies. Field trials have taken place in Pyhätunturi test power plant and in Paljasselkä and Lammasoaivi power plants, which are in commercial operation.

R&D

The Pyhätunturi test plant is still unique in arctic conditions with its blade heating systems and good measurement system. The measurements have been done in cooperation with the Technical Research Centre of Finland (VTT) and the Finnish Meteorological Institute (FMI). During 1996-97 the load measurement system was upgraded and new measurements were planned for winter 1997-98. The research activities at Pyhätunturi test plant have been limited by a total renovation of the blade heating system and a generator failure.

Kemijoki Oy arctic wind power plants.

Blade heating

A blade heating system (so-called "JE-system") developed by VTT and Kemijoki is now in use in different versions at the Pyhätunturi test plant and in the commercial wind power plants at Lammasoaivi and Paljasselkä, in the municipality of Enontekiö.

A new, integrated blade-heating element was installed in Pyhätunturi test plant in summer 1997 and the control system was modified. The new element is not sensitive to local defects in the element material; also, a continuously optimised surface heating power can be reached with the new element type.

A JOULE-project 'New Generation Wind Turbine Blade', began in July 1997, aiming to develop a new blade for MW-wind turbines. Kemijoki and VTT are responsible for the design and manufacture of the heating system for the new blade, while other partners in the project will develop the construction, materials and aerodynamic design of the blade.

O&M practices

Maintenance activities, developed during the operation of the wind power plants, were influenced by the long distances involved (see the figure above). In addition to the careful design and manufacture of the wind turbine for a cold, icy climate other factors have been important: continuous follow-up, rapid deployment of maintenance staff, adequate tools and spare part reserves and the use of local help in small disturbances are key factors in achieving high availability.

To facilitate inspection and maintenance in the winter, a special lift is used. With this, for example, the blade surface can be inspected without a large crane.

R&D production

Lammasoaivi, the first arctic wind farm in the world and the most northern, began operation in October 1996. It is owned and operated by Tunturi-Lapin Tuulivoima Oy, which is owned by Kemijoki Oy (90%) and the municipality of Enontekiö (10%). The wind farm consists of two 450 kW wind turbines, which have been modified for the arctic environment. About 2.3 GWh of electricity is produced annually, which corresponds to 75% of the consumption along the 120 km electric line to which it is connected.

During the first year of operation at Lammasoaivi the technical availability has been quite high - about 95% - though the operation has not been without problems. In the beginning, problems were caused by frozen anemometers. This was because the anemometers designed for the site were delayed and standard ones were used. Other reasons for shut downs have been high winds (> 25 m/s), service visits and small repairs.

The blade-heating system can be monitored through the wind turbine control system. During the first winter, the energy consumption for blade heating was less than 1% of the annual energy production, which was less than estimated.

Future plans

A large study, which mapped and classified the wind resource in the fell areas of Lapland, was finished in 1997. This study, which will serve as a guideline for future wind farm developments, was performed in cooperation with regional and communal authorities, the electricity distribution companies in Lapland and various other interest groups such as reindeer farmers and the tourism industry. The new wind farm plans include the enlargement of Lammasoaivi wind farm by one more turbine and the installation of two to four turbines on Olostunturi, subject to the resolution of some planning and land acquisition problems. Wind measurements on Ailigas Fell in Utsjoki have been started.

Work on drafting a long-term wind energy construction plan has begun. Economic models already used to evaluate and compare different hydropower systems have been adapted for wind power. However, more detailed models and tools to support the economic comparisons will be needed in future. These include improved energy production prediction tools and wind farm layout optimisation tools, tuned for the environment.

Conclusion

Commercial wind energy production began on Lapland fells in autumn 1996. The experience from the first year shows that commercially-competitive production is possible and that arctic regions are a clear target for wind energy production in Finland. There remains a need for continued R&D effort, as well as for a determined construction programme aiming at full-scale commercial use. The latter will also require clear public suppport in the beginning.

For more information contact the CADDET Finnish National Team in Helsinki.

The CADDET Renewable Energy Newsletter is a quarterly magazine published by the CADDET Centre for Renewable Energy at ETSU, UK.

The articles published in the Newsletter reflect the opinions of the authors. They do not necessarily reflect the official view of CADDET.

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Pauline Toole, Editor, CADDET Centre for Renewable Energy, ETSU, Harwell, Oxfordshire OX11 0RA, United Kingdom. Tel: +44 1235 432968, Fax: +44 1235 433595.