Various watercourses have been harnessed by the creation of small weirs. Height sensors at the weir send information to the hydro plant down stream as to water levels. In turn the two automatic valves regulate the flow of water by opening and closing based on the information from upstream. This ensures a smooth and uninterrupted supply to the turbine there by maximising electricity output while causing minimal disruption to river life.
The hydroelectric scheme at Bolfracks is a type called “Run of the River”, i.e. there is no storage. It was designed by Designed by Shawater Ltd of Bath in England. The water volume and height of the fall to the hydro plant governs the output from the power station. This is ideally suited for the highlands of Scotland with its many watercourses running of the sides of steep mountainsides.
It is interesting to note that 70% of power output generated is during the winter period, when the most power is needed by the grid with the long winter nights and cold temperatures.
There is an increase in small hydro power plant activity all over Scotland due to demand for green energy. Most installations are unseen from casual observation with minimum environmental disturbance.
This green electricity is sold to the National Grid thus creating another valuable source of income for Bolfracks estate while meeting the estate’s objective of being run as environmentally friendly as possible.