Applecross Micro Hydro: Local Power (Hydro to Heat Scheme)

 

Project lead: Applecross Community Company Limited

Partners: N/A

Award Amount: £18,396

Status: Complete (May 2014)

Area: Applecross (North West Highlands)

Following an initial desktop survey of eight rivers and burns in Applecross in 2009, several sites were identified as suitable for locating a micro-hydro scheme. However, financial cost constraints involved in upgrading the grid connection limited the potential export capacity to 100kW – the scope for a development was thus reduced and identification of AlltBreagach as the most appropriate single site for an installation was made. An indicative quote for over £677,000 to upgrade the grid to allow for a 100kW connection was received – SSE indicated a maximum export capacity of only 90kW using the present infrastructure. A 90kW connection was bought. A rental agreement with the landowner was secured at 10% gross income after year 9 – this was considered higher than average when compared to other community energy projects. The result of these factors meant the estimated income to the community from a micro-hydro project would be £30,000 per annum. To maximise the benefits of such a scheme to the community, Applecross Community Company Ltd sought new local uses for surplus electricity generated, including providing heat to local properties. It was envisioned that this would help reduce fuel poverty while promoting local resilience, and generating a higher financial return to the local community.

Initial analysis indicated a good correlation between the heat requirement and available supply from a hydro scheme. More detailed modelling looked at a range of factors, including: the proportion of heat demand the hydro scheme could cover; the amount of electricity exported to the grid; the amount of backup heat required when the hydro scheme was not available; and the amount of potential generation that could not be utilised, either for heating or grid export. Financial analysis was carried out and included: income from sales of electricity to the building occupants; FIT payments; and sale of electricity to the grid. However, during this modelling phase the DNO announced a further revision for the grid export capacity of only 50kW. Simple payback periods were thus calculated based on the 50kW grid export limit. Whole life costing based on a 25 year period was carried out for the most likely scheme variations, and included different options for the grid export limit, including: a permanent 50kW limit; an increase to 90kW in 2022 – which is the earliest possible date; and an increase to 90kW in 2027, allowing five years for delays.Results showed that all of the options considered have a long term financial benefit, but that installation of a 90kW hydro turbine size is the most appropriate in all cases, as it is sufficient to meet the available demand and has little – if any – unused generation. Thermal storage offers an improvement in the utilisation of the electricity generated, but not enough to be financially favourable. But with funding provision, the thermal scheme may be preferred to a hydro-only scheme.

 

Supporting Documents / Output Report(s)