The main power supply for

Shetland Shetland, also called the Shetland Islands and formerly Zetland, is a subarctic archipelago in Scotland lying between Orkney, the Faroe Islands and Norway. It is the northernmost region of the United Kingdom. The islands lie about to the no ...

is provided by Lerwick Power Station, located in Gremista, northwest of

Lerwick Lerwick (; non, Leirvik; nrn, Larvik) is the main town and port of the Shetland archipelago, Scotland. Shetland's only burgh, Lerwick had a population of about 7,000 residents in 2010. Centred off the north coast of the Scottish mainland ...

town centre. This is the principal source of electrical energy for Shetland, however currently about 20 MWe is provided by the Sullom Voe Terminal power station which comprises 4 x 23 MWe Gas Turbines, the future of which is uncertain. Opened on 27 May 1953 the station is diesel-fuelled and generates a total of 66 MW of power.

Equipment

Originally the facility had six 6 MWe Mirrlees diesel generator K Major sets (some of which have been decommissioned); two 8 MWe French Pielstick engines were added in 1983 and a further Finnish 12 MWe Wärtsilä (originally a Stork Werkspoor design) engine was commissioned in 1994. A waste-heat recovery system applied to the exhaust of the Wartsila only produces super-heated steam which runs a 2.1 MW WH Allen turbine, thus making this set a

combined cycle A combined cycle power plant is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. On land, when used to make electricity the most common type is called a combined cycle gas turb ...

. Two standby gas turbine generator units, each with a capacity of 5 MW, were installed in containers outside the existing buildings to augment peak output. The plant is operated by Scottish and Southern Energy (SSE)."Lerwick Power Station"
Gazetteer for Scotland. Retrieved 30 December 2014.

Load balancing

The growth of output from wind turbines in Shetland has increased instability in the local grid (which is not connected to the national grid on mainland Scotland). SSE installed a 1 MW sodium–sulfur battery in a nearby building to ameliorate the peak loads. however due to safety concerns, the sodium-sulfur battery was removed prior to commissioning and the energy storage building was reconfigured to accommodate 3MWh of advanced lead-acid batteries.

Replacement plan

There are proposals to replace the power station at a new greenfield site north of the existing one. Planning permission has been granted for the development however the decision to proceed has been delayed by the proposed Shetland HVDC Connection, which depending on how it is implemented may make such a station redundant, or only required as standby, which would affect the type of plant chosen.

Lerwick District Heating

There is an adjacent but district heating network see

Lerwick District Heating and Energy Recovery Plant Lerwick District Heating and Energy Recovery Plant is a district heating scheme based in Lerwick, The Lerwick District Heating Scheme is operated by Shetland Heat Energy and Power Ltd (SHEAP) while the Energy Recovery Plant (ERP) Shetland feeds i ...

. However for a variety of reasons the rejected heat has never been used as a heat source for the network. This is unlikely to happen with the existing power station as it will be closed soon.

References

{{Scottish energy Natural gas-fired power stations in Scotland Oil-fired power stations in Scotland Buildings and structures in Shetland Mainland, Shetland