Conclusions

Solar energy is the most reliable and widely available renewable energy resource for decentralized applications through thermal and electricity conversion. Domestic applications such as thermal conversion, photovoltaic conversion, solar lighting, cooking etc. are influenced by the reception of solar radiation. Solar insolation varies with geography and season, requiring assessment at local levels. Geographic information system (GIS) based insolation data is used for assessing the potential and design of the system where the variations are in acceptable limit and comparison with ground measurements have given better accuracy. Energy potential is computed based on the digitized roof area data from select villages representing all agro-climatic zones in the region with insolation details. With the knowledge of insolation reception and rooftop digitization considering high spatial resolution remote sensing data (Google earth), available potential is extrapolated to the required region of study. Solar PV installation on roof top could be effective in generating electricity from solar sources to meet the domestic energy demand.
Uttara Kannada district has more than 2,70,000 households, which has the electricity consumption of 50 to 100 kWh per month (per household). In meeting this household domestic demand rooftop solar PV systems could play an important role since district has very good solar potential. The fraction of open/wastelands in the district can be utilized to meet the electricity demand of irrigation pump sets using solar PV system. Since the whole country (in turn states and districts) is becoming an energy deficit place, need of further installation of conventional power plants can be scaled down by using decentralized or standalone unconventional methods such as rooftop PV system. Government is also encouraging the solar energy utilization by projects such as JNNSM: Jawaharlal Nehru National Solar Mission, planned to have 20,000 MW of solar energy based power plants in India. Rooftop PV system can contribute significantly to JNNSM and adequately cutting down harmful greenhouse gases and hence reduction in carbon footprint.

Acknowledgement

We are grateful to the Ministry of Environment and Forests, Government of India, NRDMS division, the Ministry of Science and Technology, Government of India, Karnataka Biodiversity Board, Government of Karnataka, Western Ghats Task force, Government of Karnataka and Indian Institute of Science for the financial and infrastructure support. We thank Bharath Settur for the remote sensing data analysis.