Micro-hydropower in drinking water gravity pipelines: a case study in Uttarakhand, India

Hydropower development on gravity-based drinking water supply pipelines in India has not been widely practiced, even at the micro-hydropower (MHP) scale. Site visits including measurements of pipeline flow and pressure were conducted at 12 schemes in Uttarakhand, and 3 were chosen for detailed analysis. Due to a complete lack of existing pressure control, the available drinking water flow would have to be reduced to enable retrofitting with MHP turbines. Technical and economic calculations were performed for a hypothetical 20% flow reduction, but showed electric power yields between just 1.2 and 3.9 kW and long payback periods between 8 and 24 years. The favoured alternative proposal is to incorporate the planning of MHP facilities into the inevitably necessary renovation and/or expansion of pipelines to both (1) meet future water demand and (2) enable the development of MHP. This hypothetical improved case showed an increase in electric power yield by a factor of 5 over the retrofitting case, and...