T.N. to harness rooftops for solar energy

Tamil Nadu government is planning a massive solar energy programme through setting up of grid-connected rooftop solar panels in government buildings.

The plan is to tap 25,000 buildings, including educational institutions, which offer 2 crore square feet of rooftop space with a potential capacity of 110 MW at an outlay of ₹940 crore, according to a document available with The Hindu.

The move follows an announcement by Electricity Minister P. Thangamani in the Assembly.

Tamil Nadu Energy Development Authority (TEDA) will be the nodal agency for implementation. Its role will include selecting vendors for implementing the project, looking at various financing options for the project and ensuring co-ordination with various stakeholders.

“This is the first big scale attempt on solarisation not only in Tamil Nadu, but also in India. It shall lead to substantive savings to the government with zero upfront investment,” said a TEDA official.

According to a rough calculation, a government building in a district by implementing a 130.82 kW system can save over ₹5 lakh in self-consumption charges and earn income of over ₹2 lakh through sale of surplus power to Tamil Nadu Generation and Distribution Corporation (Tangedco). The agency will run pilot projects in a few selected districts. Ramanathapuram, Coimbatore and Salem have been shortlisted for the pilot project. TEDA has called for proposals from vendors for 50 MW of project worth ₹250 crore. The vendor shall run the project on a BOOT model (Build Own Operate,Transfer).

Performance based pay

For the first time, the agency has introduced the concept of “performance-based payment” system. The selected vendor will be paid based on the energy produced and not upfront for the solar system installed. “The pilot projects will be built as microcosm models for the overall rollout. It is expected to use them as the learning ground for creating awareness and eliciting interest and ownership towards scaling up,” said the TEDA official.

The capacity of the solar PV system for each government building shall be calculated on the basis of the shade-free rooftop area available and the annual energy consumption of the building, he said.

TEDA will look into the tariff aspects for the project, including procedures for net metering for supply of excess power to Tangedco and will soon file a detailed tariff petition with Tamil Nadu Electricity and Regulatory Commission (TNERC).

“The success of initial ₹250 core project will, to a large extent, depend on the net metering. Tangedco has assured timely supply of net meters for this project,” TEDA officials said.

The agency would rope in Tamil Nadu Infrastructure Fund Management Corporation (TNIFMC) as an advisor and funding partner for the project.

To ensure a good savings potential for the government through this initiative, a tariff of 80{0b7da518931e2dc7f5435818fa9adcc81ac764ac1dff918ce2cdfc05099e9974} of the current Tangedco tariff of ₹8.05 per unit which comes to ₹6.44 per unit is proposed, the document said.

There will be an independent arrangement between the vendor and Tangedco, coordinated by TEDA, on exporting surplus power at a price of ₹3.11 a unit, it added. The project presents a return of 10{0b7da518931e2dc7f5435818fa9adcc81ac764ac1dff918ce2cdfc05099e9974} – 12{0b7da518931e2dc7f5435818fa9adcc81ac764ac1dff918ce2cdfc05099e9974} based on the ability to export surplus energy to the grid.