A new analysis done by Centre for Science and Environment (CSE) suggests that residential societies – which use diesel generator sets as power back-up — can easily replace them with rooftop solar power systems and save substantially on costs. “In all the residential societies where CSE conducted studies and analysis, the cost of power from solar rooftop with battery back-up was found to be about half the cost of power generated by DG sets.

“This alone should make residential societies move away from the extremely polluting diesel generator and adopt solar rooftop to meet their power back-up needs,” said Chandra Bhushan, deputy director general, CSE, while releasing the results of the analysis.

CSE’s research was aimed at understanding the economic considerations including financing and generation costs; architectural and roof space preferences; building by-laws; and constraints experienced by various stakeholders including customers, government agencies and distribution companies (discoms).

The study finds that the cost of power generation from a DG set, including the capital cost, is Rs 27 to Rs 33 per unit whereas the rooftop solar tariff is less than Rs 10 per unit.

CSE researchers have estimated that up to 3 giga-watt (GW) of solar rooftop can be installed on new residential societies over the next five-seven years. This segment can, therefore, be a key to reaching the government’s ambitious target of 40 GW solar rooftop to be achieved by 2022.

The report offers a set of recommendations, including installation of solar rooftops mandatory for all upcoming residential societies, ban DG sets in new multi-storied residential buildings except for common area loads in polluted areas, support discoms to encourage them to push solar rooftop, provide subsidy for hybrid solar rooftop systems and increase awareness among RWAs and also provide single window information and initiate campaigns.