Made in IIT solar plant powers thousands of rural homes
A solar plant of the size and cost of a centre table on your rooftop can insure your home against power cuts and halve your electricity bill. IIT Madras has invented such a ssolar rooftop installation — smaller and cheaper than present installations.
At a cost of Rs 20,000, the rooftop plant and storage system can run couple of tubelights, fans, charging points and a TV. A higher model can run all essential load minus washing machine and air conditioners of a middle class and reduce dependence on normal electricity supply.
The rooftop plant has been installed under CSR and government sponsorship in 15,000 rural homes and was successful in facing a three-day power cut during Chennai floods in December 2015.
An official in the Solar Energy Corp of India said to install a rooftop of the present technology, a middle-class family will require 1kWh solar rooftop and storage costing about Rs 1.2 lakh and a space of about 100 sq ft.
Rural Electrification Corporation (REC) has electrified 4,000 offgrid homes in Jodhpur and Jaisalmer districts of Rajasthan and 7,500 homes in Assam. Another 12,000 more homes are being taken up in hills of Assam, while some grid-connected installations have been undertaken in Odisha, Karnataka, Tamil Nadu, Telangana and Andhra Pradesh.
On Thursday, the solar power system was recognised by The Institute of Electrical and Electronics Engineers (IEEE), New York, as ‘Technology of the year 2017 in the service of humanity’.
The solar inverterless DC system is cost and energy-efficient as unlike other solar power systems, it does not convert direct current (DC) produced by a solar installation into alternate current (AC). The system comes with a full DC wiring. Each time a unit of AC is converted into DC, there is a 15 per cent loss of energy. A DC system is 2.5 times more efficient than the AC system and hence requires lesser space, said IIT-M professor Ashok Jhunjhunwala.
While a 125W rooftop solar, a 0.5kWh lead acid DC battery, and few DC electrical appliances will cost approximately Rs 20,000, a basic 500W solar power and 3 kWh lead acid storage will cost a bit over Rs 40,000 without taxes, he said. A 125W solar installation will require 10sqft space, while 500W requires 50 sqft of space, said Venkat Rajaraman, chief executive officer of Cygni Energy that is commercialising the technology.
Jhunjhunwala said a solar-DC microgrid could help break the logjam that the domestic power supply currently faces in India.