Wind, wave and tidal energy currently represent Orkney’s ‘big three’ in terms of renewable energy, however there are few other methods of renewable generation to be found scattered across the county.
Solar energy involves capturing and harnessing the sun’s energy. While Orkney is not renowned for its sunny weather, solar panels can still be fairly successful in the county and are used in both domestic properties and commercial set-ups. Orkney had 334 solar installations as of March 2015, including a couple of larger scale arrays, notably at the Orcadian in Kirkwall as well as the primary school in Stromness. OREF is currently running a solar microgenerator database to capture information about the efficacy of solar panels in Orkney.
Biomass, also known as biofuel or bioenergy, is obtained from organic matter, either directly from plants or indirectly from industrial, commercial, domestic or agricultural products. The use of biomass is generally classed as a ‘carbon-neutral’ process because the carbon dioxide released during the generation of energy is balanced by that absorbed by plants during their growth.
In Orkney’s case however, the lack of trees or other suitable organic matter has made the production of bio-fuel a less immediately practical solution than in some other areas, and biomass is currently limited to the installation of domestic boilers running on imported biomass pellets. There have been several trials conducted, both on Westray and Mainland Orkney, looking into the possibility of growing dedicated biomass crops in the county, however these have not yet led to any large scale biomass production in the area. The main biomass potential in Orkney may lie in the production biogas through the anaerobic digestion of slurry, however this has not been fully explored.
Heat pumps are widely used in Orkney, both domestically and on a larger scale. Orkney’s mild climate lends itself to heat pumps being used in domestic settings and many units can be seen on the exteriors of dwellings and public buildings. Notable examples include ground source heat pumps at Kirkwall Grammar School, Stromness Primary school, Papdale Halls, and the new developments at the Pickaquoy Centre. Unusually, a seawater heat pump can also be found in Orkney Islands Council’s Warehouse Buildings in Stromness. Heat pumps are especially effective as a renewable energy technology in Orkney, as even the electricity they use to run is produced from a significant amount of renewable sources.