The secluded community of Hengbung, located in northeast India’s Himalayan foothills and sometimes pounded by severe winds and landslides, is accustomed to protracted power outages. (renewable power capacity)
However, the village’s difficult environment — it is mountainous, difficult to access, and crisscrossed by streams — is now providing a chance to secure the community’s reliable electricity. Last July, a pumped-storage hydroelectric system with solar-powered pumps began operation in the village, making it India’s first such project to combine hydro with solar. Built on a stream, the plant has two interconnected reservoirs and functions essentially as a big water battery, storing renewable energy for subsequent release during grid failures or when demand is higher.
According to the Foundation for Environment and Economic Development Services (FEEDS), a local NGO involved in the effort, residents now have continuous lighting in their homes and streets as a result of the system. “The project has made a significant difference in the lives of our villagers by combating darkness while keeping the environment clean,” said FEEDS founder Haokholet Kipgen, a Hengbung native and the local political spokesperson for the surrounding area. The project, a collaboration between FEEDS, the NB Institute for Rural Technology (NBIRT), and Visva-Bharati University, is funded by the central government in the amount of 29 million rupees ($353,195).
According to government data, India, one of the top worldwide emitters of greenhouse gases, plans to grow its renewable capacity to 500 gigatonnes (GW) by 2030, up from approximately 120 GW now.
Hydropower has been identified as a critical component of this, as it can offer continuous power when other green energy sources, such as solar and wind, are constrained by inclement weather. However, as renewable energy generation increases, particularly solar power, energy storage is required to ensure that the nation’s grid stays stable around the clock and that disruptions are avoided. According to the India Energy Storage Alliance (IESA), India’s entire operating battery storage capacity is around 50-megawatt hours (MWh).
According to a recent analysis by the Council on Energy, Environment, and Water (CEEW), the country’s need by 2030 will be 327 gigatonne hours (GWh). Pumped-hydro storage projects (PSP) could be a crucial solution, according to energy experts, and India’s power ministry has announced drafted rules to promote the technology.
In India, there are currently eight operational PSPs with a total capacity of roughly 4.7 GW, with the majority getting their primary operating power from the national grid. However, the Indian government has identified approximately 120 locations for the technology, with a total storage capacity of 103 GW.
Nine more PSPs have been commissioned, with three more currently under construction, according to energy analysts, and private power corporations are now trying to combine hydropower with clean energy, following the example of the Hengbung milestone system. “Such projects demonstrate the path to a sustainable energy future by integrating renewable energy with hydroelectric power and storage,” said Santi Pada Gon Chaudhuri, NBIRT’s creator, and central government energy advisor.
The Hengbung PSP contains two interconnected reservoirs with a total capacity of 1.9 million liters of water, which is roughly three-quarters of an Olympic swimming pool.
During power outages, which are frequently caused by snapped transmission cables or transformer failures during monsoon rains and winter, the upper reservoir releases stored stream water to power a turbine, supplying green power to the grid. This discharged water then accumulates in the lower reservoir before being pumped back upstream using solar power to make it available for power generation again. Excess solar electricity is sent into the national grid during the monsoon season when there is plenty of stream water to drive the turbine and replenish the upper reservoir. According to energy experts, PSPs have a longer lifespan than lithium-ion or lead-acid batteries, lasting at least six decades.
“Pumped water storage systems can be a dependable option … especially when renewable sources such as the sun or the wind may not be available to match the electricity demand,” said Disha Agarwal, senior program lead at CEEW, a think-tank.
Due to the environmental and social implications, major hydroelectric facilities being planned in other Himalayan locations and regions of India have provoked massive protests from communities.