Pumped storage: Releasing the pressure on isolated electricity grids
The Faroe Islands will use wind power to pump water back up into hydroelectric dams as a means to balance their electricity grid.
Mountainous: The Faroe Islands have little vegetation to slow down rainwater as it flows into the seas.
The Faroe Islands, an autonomous territory of Denmark, is located between the Atlantic ocean and the Norwegian sea. Their 50,000 inhabitants have similar energy needs to Europeans on the continent, but they do not have the luxury of a variety of energy sources to balance electricity supply and demand. Therefore, like many other islands, they must import of fossil fuels to meet their energy needs. This reliance on oil means the islands are one of the largest polluters of CO2 per capita in the world.
However, the picture isn’t so bleak, the island has a range of renewable energy resources at its disposal. Being in the middle of the ocean, there is obviously a lot of wind. The climate is greatly influenced by the Gulf Stream, meaning it is humid, with a lot of rain. But although there is some potential for hydro power, a lot of the water flows straight off the hills and into the ocean because there is no vegetation to soak it up and help it accumulate in lakes. There has been some investigation into the geothermal energy potential on the island, with promising results, and some early efforts into exploiting tidal power have already been started.
Currently, about 55% of the electricity supply comes from small power stations run on oil. The rest comes from hydro power, and some wind. The islands have a goal of covering 75% of their electricity production with renewable energy sources within 2020.
As the share of renewable energy in the electricity mix increases, the Faroe islands will have to cope with the instability and unpredictability of wind as a power source. In most countries, this is partly solved by exchanging electricity between different areas when one region lacks wind. But because of the Faroe Island's size, a wind less day will usually mean no wind power on the entire grid. To complement the wind turbines, therefore, they need to find a means of storing the wind energy for later use.
At Vestmanna, they are examining the possibilities of establishing a hydro power station with pump storage between two lakes. 1 MW wind turbines along the upper lake will be used to pump water directly up to the lake when there is enough wind. To produce electricity, the water flows back down through a generator, as in a normal hydro power station. As much as 70-80% of the original energy from the turbines will still be converted to electricity, only now it can be produced whenever the electricity is needed.
The islands' problems are shared by many isolated areas of the Nordic countries, like Iceland, Greenland and the northern parts of Norway, Sweden and Finland. In scarcely populated areas like these, energy demands can be small, and spread over large areas, but the grid still needs the same flexibility as one connected to many energy sources and consumers. To cope with these challenges, the Nordic Council of Ministers have established the working group for scarcely populated areas. It aims to exchange information and experiences on decentralised energy supply, focusing on local, sustainable energy solutions.
