Drawing from the sun to counter power cuts and hike in tariffs

While unscheduled power cuts and hike in power tariffs may have residents seething, some with an ecological turn of mind have taken to experimenting with alternatives sources of energy. While few industries and educational institutions have taken the green energy route, homes in the city too are seeking solutions that burn no holes in either the ozone layer or the pocket. At the residence of Ravi, retired scientist from the Central Electrochemical Research Institute, at Cantonment in the city, fans, lights, computers and a host of small gadgets have been powered by energy tapped from the sun for the last one month. He has installed a solar photovoltaic unit on the rooftop of his apartment that converts sunlight into electrical energy.

The 750 watt unit comprises of solar panels, cells, wires, battery and UPS. “One phase of the three-phase-current at home is powered by solar energy. This phase has all the fans, lights and small gadgets.” A backup power source stores energy and comes in handy during unscheduled power cuts at nights.

“I was concerned about excessive thermal energy consumption. This has been my dream for 20 years but it was possible only now as cost of solar panels have considerably reduced from Rs. 400 per watt to around Rs. 200,” explains Mr. Ravi.

Eighty per cent of the cost of the solar power unit goes towards the panels. Installation, transportation, battery and inverter account for the rest totalling up to Rs. 1.5 lakh. The conventional EB source supplies for washing machine, air conditioner and electric kettle. “The refrigerator and water motor can be powered by solar energy but they require a higher range of starting power, which cannot be drawn from the UPS. I have saved more than one unit per day, perhaps with the refrigerator around 2-3 units maybe possible.”

On the viability of the project, Mr. Ravi agrees that excise duty on solar panels and other components, maintenance of batteries, and requirement for specially adapted solar inverters go against favour. Solar power may turn out more economical for apartments and offices that hesitate to opt for it citing elevators as a reason.

Government subsidies can make solar energy popular among the public.

The initial investment for solar unit may not be affordable by middle class, says railway employee Sethu Madhavan who is experimenting with a model for homes that supplements solar energy with conventional EB power. With a keen interest in renewable energy, he has devised a model for his friends in Srirangam.

“My project is for middle class houses looking to cut down power tariffs. Initially it started out as one or two lights. Now the 200 watt set –up can power moderate consumption including fans and lights.”

Heating options popular

Solar water heating as an option has been explored for some time by hostels, homes and hospitals. The set up may work out for large households feels, Subha Rengarajan. “I found solar heating feasible over purchasing individual geysers for five bathrooms; besides solar water heating is hotter than electrically heated water.” Except on occasions of continuous rain for three days, it is an effective heating solution, she adds. Though space constraint for panels and short shelf life and cost of batteries make it a risky proposition, says Dr.Govindraj whose hospital has solar water heating. “In winter there is a need to supplement with an EB source.”

Light up differently

In the case of lighting, LED is considered an eco-friendly solution. The initial cost may run to a few ten thousands as the number of lights installed is relatively more. “It is a worthwhile investment as power tariffs have reduced by one-third. The lights guarantee a million hours,” says Gopal.

A study conducted by the Department of Environmental Science ,Bishop Heber College, that has proposed to replace all incandescent lights with LED lights in phased manner, has revealed that the initial investment for the lights can be recovered in two or two and a half years, says Mr. Alagappa Moses, head of the department.