Hengbung, a remote village in Manipur, has a first-of-its-kind utility worth replicating elsewhere too — a micro solar pumped storage facility supplying 24×7 power to 50 households. 

Today, large-scale pumped hydro systems are the in-thing and many companies are pursuing them as an infrastructure for storage services. But Hengbung seems to illustrate that micro-scale systems are feasible too. 

The system utilises solar energy to pump water from a lower reservoir to an upper reservoir during periods of high solar irradiance. This stored water can then be released through a micro-hydro turbine to generate electricity when solar power is not available or when there is high energy demand.

“This innovative technology combines solar power and micro hydropower benefits, creating a hybrid system that can efficiently store and dispatch energy as needed,” says a case study published in Akshay Urja, an in-house publication of the Ministry of New and Renewable Energy. 

Reliability

The key components of the system include a 40-kWp solar photovoltaic array, upper and lower pumped storage reservoirs of 900 cubic metre capacity each, a 4×10 HP solar pumping system, and a 12-kW micro-hydro unit, which can handle loads up to 12.5 kVA while maintaining voltage stability of 217-243 V and frequency between 48.75 Hz and 51.25 Hz. 

The micro system has achieved an average generation consistency of 88.6 per cent, “indicating its reliability in meeting the energy demands of rural communities”.

The article notes that by harnessing solar power and micro-hydropower, the system has achieved a 92 per cent reduction in greenhouse gas emissions compared with conventional grid power.