Allt Breugach was chosen from three sites on which initial design studies were carried out, for its combination of catchment and head (the drop of altitude over the scheme length). The hydro resource figures are informed by technical assumptions made by hydro consultant, Highland Eco Design and a hydrology report based on 12 months’ measurements by environmental consultants MNV Consulting. The estimated output is 447,061kWh each year. The water resource figures are approved and fully consented by SEPA.
The hydro scheme is a run of river scheme using water from Allt Breugach, with an installed capacity of 90 kW. The intake will draw water from the burn and convey it via a buried pipeline (the penstock) to a turbine house which will sit discreetly within one of the farm fields within easy access of the road. The turbine will generate electricity for export to the national grid. As the maximum grid connection currently available is 50kw, a diversion load will be created to use the remaining 40kw until the community accesses funding to build a district heating scheme to provide affordable green heat to housing and businesses nearby. Water will be returned to the river via a short tailrace pipe. The amount of electricity generated at any one time will depend on the flow of the river. A compensation flow, as required by SEPA, will protect the ecology of the river system.
The society will receive the market value for the electricity exported to the National Grid, which comprises a mix of wholesale value plus secured government incentive payments known as Feed in Tariff payments (FiTs). The scheme is eligible for FiTs payments for the full 90kw generated. Rates are locked in at 20.09 pence per kWh and are index linked to RPI. They are payable for the first 20 years of the scheme.
The overall cost of the project is £780,000. Of this, £746,000 is construction and development costs and £34,000 is to cover operating costs for the first year after commissioning, until income from FiTs is paid. Members’ return is currently forecast at 4% (excluding any tax reliefs), with members’ capital returned by the end of a 20 year period.