Evaluation of the energy recovery potential at City of Masvingo waterworks using micro-hydroelectric generator

Abstract

The potential of implementing energy recovery in the water supply network of the city of Masvingo is
investigated. Data from the city’s department of engineering was analysed to determine the critical
parameters for a hydro-generator. Determinations of the head, maximal discharge and penstock diameter
were made. With a maximal discharge of 289 l/s and a gross head of 66 m, an estimated energy recovery
potential of 168 kW was possible. This is an amount of power sufficient to power all the operations at
town house where a 75 kW diesel generator serves as a standby power source. The annual energy
recoverable is estimated to exceed 700 000 kWh which is equivalent to more than US$70 000 at the
prevailing electricity tariffs in the country. It was noted that the water delivery was limited to only 12 h a
day, hence a standalone generator may not be suitable but implementing a peaking generator integrated
into the mains is recommended.