India currently has an installed capacity of nearly 61.97 GW of solar power and has set an ambitious target of attaining 300 GW of solar capacity by 2030. The estimation of solar energy potential at a given location is primarily dependent up on the incident global horizontal irradiation (GHI) at a given location during a year. The world irradiation maps developed by SolarGIS were, till recently, the most widely used information source for assessment of solar energy potential in India.

ISRO has developed a Solar Atlas for India using the GHI derived from the Indian geostationary satellites such as KALPANA-1 and INSAT 3D. The Solar Calculator Application on VEDAS was developed for wider dissemination of satellite-derived incident solar energy estimates. The Solar Calculator application provides annual, monthly and long-term monthly average of GHI, along with sun-path, terrain horizon intersection, temperature profile, 72-hour GHI forecast, and multi-criteria solar site selection tool. Moreover, the application provides technical potential of rooftop solar energy in 100 smart cities and 60 solar cities. The application also features building shadow analysis using 3D city models derived from Cartosat-3 satellite images to aid building level solar energy potential estimation in Ahmedabad and Gandhi Nagar cities of Gujarat as pilot studies.

SAC has now developed a Solar Calculator for Africa upon request of the International Solar Alliance (ISA). The Solar Calculator for World has been developed as part of India’s commitment to COP26.

The website and an android app benefit citizens, policy-makers and industry. They are encouraging maximum utilization of solar energy resources in India. The Solar Calculator Application on VEDAS has enhanced the accuracy. It aids financial institutions for better project evaluation for investment guidance. The API and WMS links of solar energy potential are available to interested academic institutions, Start-ups and private sector entities. The application guides Citizens by estimating monthly solar energy generation from building rooftop for solar panel installation. The solar energy forecasts can aid Solar Power Plant operators in scheduling operations.

Annual GHI Estimate by ISRO

Solar Site Selection Tool on VEDAS