From the rooftop

Vijay C Roy

The individual rooftop solar power system is yet to catch fancy of homeowners mainly because the return on capital invested in the plant is tardy even after substantial subsidies. It takes almost five to six years to break even. For residents of Chandigarh, this period could be little longer because of lower electricity rates. Other dampeners include damage to the roof terrace aesthetics and difficulties in keeping solar panels clean.

The arithmetic

According to a back-of-the-envelope calculation, the cost of a 5kW capacity plant, required for a 500-square yard house, is about Rs 3,25,000. A Chandigarh-based customer is required to pay Rs 2,35,000 for it after availing the 30 per cent subsidy. At an average plant efficiency of 20 per cent, the consumer would consume 20 units a day. Thus, he could recover the investment in about 6.5 years. Therefore, many do not find it a valuable proposition. 

Therefore, the Chandigarh Administration has made rooftop solar power plants mandatory for group housing societies and individual houses of 500 square yard and above. While installation of rooftop solar plants was made mandatory for new houses two years ago, the owners of existing houses had a two-year moratorium that will end on May 17, 2018. For residential buildings measuring 500 square yard to 999 square yard, installing of 1 kW capacity is mandatory in the city.

Haryana also had a similar policy since 2014. Consumers in both places get an incentive of 30 per cent Central subsidy. Neighbouring Punjab is, however, silent on mandatory installation. Although, private individual houses in Punjab generate around 3 MW solar power.

The City Beautiful

The administration in Chandigarh is now using the carrot-and-stick policy to develop the Union Territory as a model solar city. The target is to install 50 MW solar power plants by 2022. Initially, the progress was slow. Only 86 residents had installed solar photovoltaic totalling 504 kW with net metering at their residences by July last year. Alarmed, the UT Administration directed the Estate Office to take action against non-compliance after the deadline, i.e., May 17, 2018. The tough approach bore results. The total installed capacity jumped to 3.3 MW with more than 200 houses opting for solar rooftop plants in just eight months, besides 300 pending applications. In addition to this, a capacity of 21.3 MW solar rooftop have been installed in government buildings.

Energising Haryana 

Haryana, however, lagged behind. According to the Haryana Renewable Energy Development Agency, so far 25 MW of subsidised solar rooftop plants have been installed.  With increased awareness, the demand also came from the commercial consumers. As a result, 5MW solar power is produced from both residential and commercials rooftop panels in Gurgaon alone. Currently, the total rooftop solar power generation in the state, including non-subsidised plants, is 85 MW.

PRACTICAL ISSUES

• Solar power plants have low operational and maintenance requirements
• Periodic cleaning of solar modules is, however, a must to maximise efficiency 
• In places of dust, cleaning of modules is carried out more frequently 
• Return on investment in the rooftop unit is delayed due to huge capital cost