Small hydro power
This chapter is limited to small-scale hydro power (SHP), since large-scale hydro power is technically mature and its R&D requirements - mainly refinements by the large specialist companies active in this field - are generally being well taken care of. Indeed, the development of SHP has tended to be neglected, partly due to the false but widely held impression, gained from the maturity of large hydro, that there is not much scope for technical development and improvement of any hydro power systems. There is, however, considerable scope for improving the cost-effectiveness of SHP, especially with low-head systems, through both technical and non-technical innovations. 2
There is no general international consensus on the definition of SHP; the upper limit varies between 2.5 and 25 MW in different countries, but a value of 10 MW is becoming generally accepted, as, for instance, by ESHA (the European Small Hydro Association).3 This chapter will therefore use the definition for SHP as any hydro systems rated at 10 MW or less. SHP can be further subdivided into mini hydro, usually defined as <500 kW, and micro hydro, <100 kW.