Marine engineer Saswat Das’s interest in solar and renewable energy applications grew after his DIY project that involved him setting up a solar power plant in his home.
A year-and-a-half ago, Das started his enterprise Sunmeister Energy, that dealt with energy auditing and solar-powered installations.
At a recent event, Das spoke about making better lifestyle choices that can help conserve energy in daily life.
Excerpts from an interview:
What are some common misconceptions about energy conservation?
People think that industries consume more energy, but the fact is that residential living uses 29 per cent of the entire energy generated.
Forty-one per cent of the energy created worldwide comes from coal and based on our current consumption patterns, by 2035, we will require an additional 90 per cent of energy.
Explain the concept of energy loss.
Take the case study of a 100-Watt bulb: 329 Watt (W) of energy from coal is burnt and post the losses in the boilers and turbines, only 115W of useful electrical energy is supplied.
An additional 15W is lost in transmission resulting in a final supply of 100W, of which 90W is wasted in heat. Only 10W is converted to light. You are, however, paying for 329W. Instead, if you use a 15W CFL bulb which provides the same luminosity, it would require only 83W of coal to be burnt. An LED bulb uses even less — just 48W of coal.
What is the common energy consumption pattern in Chennai households?
From a survey among 40 mid-level urban households in Chennai, we found that 8 per cent of energy is consumed by lights, 10 per cent by fans, 19 per cent by electrical equipment like washing machines and refrigerators, and 13 per cent by miscellaneous equipment. Air-conditioners consume a monstrous 50 per cent.
Refrigerators could also be a silent cause eating into your energy bills. A good fridge should run for 5 to 10 minutes and cut off, but in older fridges the insulation fails, so it keeps running to cool. You can reduce one-third of your energy consumption by upgrading to the latest model of your equipment.
What is a typical solar energy system?
The system comprises solar modules, an inverter and maybe a charge controller and batteries depending on type of system. The grid interactive system is largely maintenance free and should last for 25 years. The power produced from the panels gets converted to energy for consumption at home.
In case this power is not utilised, it gets transported through a government provided net meter to the main power grid.
It is a seamless transition where the solar inverter (during the day) supplies power to the house/office/factory. In case of a power cut, the system is built to shut down as it is enabled with an anti-islanding function.
Is there a system with a backup plan?
In the hybrid system there are backup batteries that kick in when the power fails. Although it stabilises the voltage, it is 1.5 to1.7 times more expensive than a grid interactive system.
In cities where power cuts are not that frequent, investment in batteries makes little sense as they deteriorate with time and are hardly used. We mostly recommend the basic grid interactive system and a backup home inverter that takes care of your essential needs in case of a power failure.
What is the actual monetary advantage of switching to solar?
One unit in the EB is equal to one-kilowatt hour. The cost per unit varies from Rs.1 to Rs.6.50, depending on your consumption.
For instance, you currently pay Rs.6.50 per unit if you cross over 500 units bimonthly (for residences), and Rs.8.05 for commercial spaces. With solar power sustaining your home, you can hedge the energy costs for the futureand arrest further rise in costs.
