The main power supply for Shetland is provided by Lerwick Power Station, located in Gremista, northwest of Lerwick town centre. This is the principal source of electrical energy for Shetland, however currently about 20 MWe is provided by the

Sullom Voe Terminal The Sullom Voe Terminal is an oil and gas terminal at Sullom Voe in the Shetland Islands of Scotland. It handles production from oilfields in the North Sea and East Shetland Basin and stores oil before it is transported by tanker. Constructio ...

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 A diesel generator (DG) (also known as a diesel Genset) is the combination of a diesel engine with an electric generator (often an alternator) to generate electrical energy. This is a specific case of engine generator. A diesel compression-ig ...

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 Wärtsilä Oyj Abp (), trading internationally as Wärtsilä Corporation, is a Finnish company which manufactures and services power sources and other equipment in the marine and energy markets. The core products of Wärtsilä include technolo ...

(originally a Stork

Werkspoor Werkspoor N.V. was the shortened, and later the official name of the Nederlandsche Fabriek van Werktuigen en Spoorwegmaterieel. It was a Dutch machine factory, known for rolling stock, (ship) steam engines, and diesel engines. It was a successor ...

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. Two standby

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...

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 plc (formerly Scottish and Southern Energy plc) is a multinational energy company headquartered in Perth, Scotland. It is listed on the London Stock Exchange, and is a constituent of the FTSE 100 Index. SSE operates in the United Kingdom and ...

(SSE)."Lerwick Power Station"
Gazetteer for Scotland. Retrieved 30 December 2014.

Load balancing

The growth of output from

wind turbines A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. Wi ...

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 A sodium–sulfur battery is a type of molten-salt battery constructed from liquid sodium (Na) and sulfur (S). This type of battery has a high energy density (its energy density is 5 times that of a lead-acid battery), high efficiency of charge/ ...

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 Shetland HVDC Connection is a high-voltage direct current submarine power cable under construction to connect Shetland to the British mainland. Current status In April 2022, the project was described as "on track to be completed by 2024". The s ...

, 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. 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