Summary: Micro-hydro feasibility study including site assessment. Review of turbine options and project costs and paybacks

Client: private home owner

Key suppliers: Ecovision Systems Ltd

Completion Date: 2007/2008

Leading Energy provided the technical advice alongside renewable installation company Ecovision Systems. This project was too small to be of interest to major hydro suppliers but the potential power available still had merit to the client.

The site was an old mill site with a mill pond and weir intact with low head (about 5m) and variable flow from 10 l/s up to 120 l/s. The site assessment involved measuring the potential head for the site and several site visits to measure the flow rate (using the rectangular notch method). After pressure drop losses had been estimated for the feed pipework the potential power for the site indicated that paybacks on current ROC’s gave an unacceptable payback for the electricity saving.

From a technical perspective approximately up to 1kW of power could be generated from the site with a grid connected system but the design and capital costs are similar for  hydro projects up to 5kW but without the paybacks to make it worthwhile.

If the feed-in tariff rate for renewable energy increases to be closer to the supply cost then this alters the whole basis for small hydro schemes like this one. Site assessment over the annual cycle is important to ascertain the viaibility of any hydro project to build an accurate flow duration curve

Useful links:

british-hydro for information on micro-hydro

berr for the latest on Renewable Obligation Certificates (ROC's)