Modernisation and automation of small hydropower plants

Small hydropower plants with a power typically under 1 MW per unit are technically mature and have high operational availabilities. Due to the pressure of costs from increasing environmental requirements, increasing steel cost and exploitation of economically challenging sites especially those with low heads, innovations are required for the economic operation of new plants as well as for modernising existing ones. This paper provides a short overview of typical measures, introduces new technologies and trends for small turbines and concludes with the state of the art of variable speed concepts.