High efficiency light bulb in field of grass


Small-scale hydropower is one of the most cost-effective and reliable energy technologies to be considered for providing clean electricity generation. In particular, the key advantages that small hydro has over wind, wave and solar power are:

  • A high efficiency (70 - 90%), by far the best of all energy technologies.
  • A high capacity factor (typically >50%), compared with 10% for solar and 30% for wind
  • A high level of predictability, varying with annual rainfall patterns
  • Slow rate of change; the output power varies only gradually from day to day (not from minute to minute).
  • It is a long-lasting and robust technology; systems can readily be engineered to last for 50 years or more. It is also environmentally benign. Small hydro is in most  cases “run-of-river”; in other words any dam or barrage is quite small, usually just a weir, and little or no water is stored. Therefore run-of-river installations do not have the same kinds of adverse effect on the local environment as large-scale hydro.