Optimizing power generation and cost efficiency in a solar-powered building

During the 2021 United Nations Climate Change Conference, India set a goal for net-zero carbon emissions by 2070. Kolkata, a city in the state of West Bengal, is a designated smart city with buildings powered by renewable energy that is currently helping the country achieve its goal.

Mukherjee et al. simulated the energy consumption and generation of a proposed building in Kolkata to determine the optimal orientation for building applied photovoltaic (BAPV) energy generation.

“This work indicates that 51.19% of the annual energy requirement is met through renewable energy generation for optimum orientation with 0° tilt angle for rooftop solar, which is better than the 15° tilt angle for rooftop solar in the actual [designed] orientation,” said author Arijit Mukherjee.

At a 15° tilt angle, the solar cells meet 51.04% of annual energy demand of the building, producing 611 kWh/kW_P/year (kilowatt-hours per kilowatt-peak per year) and 146.28 MWh (megawatt-hours).

The simulation considered current building and construction regulations, 10 years of weather data, and the Energy Conservation Building Codes, which specify the minimum energy conservation requirements for commercial buildings in India.

The researchers also performed an economic analysis and found that the expenditure cash flow for the designated building orientation will be higher than the optimum orientation from their simulation after 10 years, and after 30 years, power generation from the BAPVs would account for 35.24% of net savings.

“The building & construction sector is responsible for around 24% of total energy and process-related CO₂ emissions in India,” said Mukherjee. “This research is inevitable for a sustainable future and to meet the target set by India and reduce the dependency on fossil fuel-based electricity generation.”

Source: “Techno-economic sustainability analysis of solar energy integration on a commercial building at Kolkata, India - A simulation-based case study,” by Arijit Mukherjee, Biswajit Thakur, and Biswanath Roy, Journal of Renewable and Sustainable Energy (2025). The article can be accessed at https://doi.org/10.1063/5.0289946 .