Project Spotlight


8 MW / 6 MWh
A balanced grid for the Scottish Shetland Islands

Energy storage enabling more flexible operations

Smart storage with service solutions to secure power supply

A reliable electricity supply is essential to the local community living on the Shetland  Islands, a subarctic archipelago in the Northern Isles of Scotland. The Lerwick Power Station is the main generator for the grid, with an obligation to deliver uninterrupted power to the island community. The introduction of energy storage will enhance the islands’ security of supply and reduce operating hours on the diesel generators.

Wärtsilä’s 8 MW / 6 MWh energy storage system and GEMS Digital Energy Platform are enabling an increased integration of existing renewable power into the power system, which will help lower CO2 emissions. A combination of flexibility solutions is setting the Scottish archipelago on a path towards a cleaner energy system.

Main Data

Customer Scottish and Southern Electricity Networks Distribution
Site size 8 MW / 6 MWh
Site locations Shetland Islands, UK
Applications Island Grid+, Grid reliability, Renewables integration
Scope of services Engineering, procurement and construction (EPC)
Delivery 2021
Drone image of cliffs in Scotland

As the electricity distribution network operator responsible for ensuring homes and businesses in Shetland receive a safe, secure and reliable supply of electricity, we're investing in Lerwick Power Station to support full duty operations of the station before it transitions to standby operation when Shetland is connected to the Great Britain electricity system via high-voltage direct current link. The Wärtsilä energy storage system will enhance the inslands' security of supply, while at the same time lowering our carbon footprint."

Facilitating the islands' energy transition

Wärtsilä’s energy storage solution will facilitate the optimal integration of the existing 12 MW of wind and tidal-generated electricity into the grid, estimated at more than 4300 MWh/annum, while providing further stability to the entire energy system. The system can instantly deliver power in cases where energy supply is interrupted, or support intemittent energy sources, like wind.

The station is currently using diesel generators at partial load in order to have enough capacity in reserve. The storage solution will displace spinning reserve, minimising the operation of diesel generators and storing energy for dispatch as needed, estimated to provide more than 1000 tonnes of fuel savings and 3400 tonnes of CO2 reductions for the customer annually.

The Wärtsilä energy storage system enables local grid modernisation, ensures more reliable energy supply, and accelerates decarbonisation of the power network.


Wärtsilä's Solution


Ensure a balanced grid for the secure supply of (reserve) power

Reduce the operating hours on current diesel generators and displace spinning power generation

Enhanced security of power supply

Upgrade existing infrastructure and integrate renewables to support a reliable islanded grid

Modernise the grid by providing extra energy supply via the storage solution that can instantly deliver power if there are power supply interruptions

Improved utilisation of existing wind power into the system, resulting in further energy infrastructure stability, and reduced CO2 emissions and fuel costs

Integrate and optimise penetration of wind turbine-generated electricity into the grid with the GEMS Digital Energy Platform