Clean Tech

The sleeping giant is waking up

M Ramesh | Updated on March 12, 2018

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Solar heating for industrial use is on the cusp of taking off, writes M Ramesh

Bhoo Thirumalai, the Chief Executive Officer of Aspiration Energy and a solar aficionado, is a busy man these days. For years, the man who co-founded the successful IT company had been trying to rev it up with limited success. But suddenly things seem to be falling in place. In the last seven years, Aspiration has done about 20 solar installations, which add up to 2.5 MW. And now, there is so much business on hand, that Thirumalai expects to do 20 MW in the next one and a half years.

The numbers might still appear small, but then Aspiration Energy is into the ‘other solar’. These days, when people talk solar, they talk of PV and electricity, but there is another sleeping giant that has been practically forgotten — solar heating. Solar water heaters have been around for some time now, but tapping into the sun for providing heating to industrial process, seems to be, by empirical data, on the cusp of taking off. “Concentrated solar thermal’s installation base is about 20 MW in India today, but more than half of it got added in the past three years,” says Siddharth Malik, Managing Director, Megawatt Solutions, a company that specialises in the area. The rate of growth is at an all-time high, notes Malik.

Success stories

So, what triggered the trend? Industry sources point to a bouquet of answers, the most significant of them being an increased in awareness. It takes one or two success stories to set a precedent. Then the ‘herd mentality’ takes over and everybody else rushes in.

Take, for example, the case of Wheels India, which manufactures wheels for automobiles. The production process needs hot water to remove grease off the wheels. It used to heat water by burning 3,000 litres of furnace oil every day. When the company decided to make the switch to solar-based heating, about three years back, the furnace oil cost used to amount to ₹1.65 lakh a day.

Wheels India is one of Aspiration Energy’s marquee customers. Aspiration’s clinching argument was its ‘opex model’ — Aspiration would do whatever investments were required upfront, and let Wheels India pay it out of its savings in furnace oil cost. The saving turned out to be ₹20,000 a day. Now, Wheels India wants to do more in terms of solar heating.

Wheels India is part of the TVS group. Having seen the example of their group companies, other companies are now showing interest.

Today, there are many similar examples. These include Parle, Mother Dairy, Sona Koya, Thirumalai Chemicals, Owens Corning Industries, Synthokem Labs and Himachal Pradesh Milk Co-operative. These are the pioneers who have cleared the minefield, and many others are raring to follow.

Maturing technology

A conservative estimate of the Indian market for solar heating for industrial purposes (or, SHIP) is 20,000 MW — thousand times the existing capacity. Solar heating makes sense where the heat requirement is less than 250 degrees Celsius, and there are many industrial processes that need only that much heat. Textile, for example, needs only between 60 degrees Celsuis and 150 degrees Celsius. Automobile industry rarely needs more than 200 degrees, pharmaceutical about 230 degrees Celsius. Solar can easily replace fossil fuels as the heat source for these applications.

Roughly a third of India’s oil imports are used for industrial heating and solar thermal has potential to reduce a majority of this, says Malik. “It is a market than that addressable potential exceeding 20 GW, which translates to US $10 Billion opportunity,” he says. His company, Megawatt Solutions, today accounts for a fourth of the 20 MW installed, and its 5 MW of installed capacity replaces 10,000 tonnes of oil.

The maturing of technology is also helping, says Malik. Solar heating is simple enough, you could just let the sun heat the air you trapped between two layers of glass and pipe off the air to, say, dry a painted surface or a tray of fish. This could get you up to temperatures of around 85 degrees. But higher temperatures are possible with ‘parabolic dish concentrators’. Navkar Textiles’ plant in Jodhpur, Rajasthan, has 12 giant parabolic dishes, each with an area of 16 sq metres exposed to the sun, making 192 sq metres in all — that system generates 150 degrees Celsius heat (at 3 bar pressure). Navkar Textiles spent ₹36 lakh on the solar heating system, which saves it ₹20 lakh every year in fuel costs. Since the system, made by a Rajasthan-based company called K-Energy, was eligible for the tax-saving ‘accelerated depreciation’ incentive, Navkar reaped bumper profits.

Climb up a notch or two further on the technology ladder, you get systems with trackers — they face the sun always. An installation of Megawatt Solutions for a rubber-based product company in Gujarat heats a ‘thermic fluid’ to 250 degrees Celsius.

As these examples get known, more and more industries are getting attracted to solar heating. “Time has come to wake up the sleeping giant called ‘concentrated solar heating’,” says Malik. “We are set to grow at 200 per cent CAGR over the next five years.” The emergence of the ‘opex model’ offered by companies like Aspiration Energy, is also helping raise traction.

Thirumalai notes that the solar heating industry has one challenge to overcome. Unlike in the case of electricity, there are no standardised meters for measuring the quantum of heat energy supplied. To determine the energy delivered, companies such as Aspiration Energy have to design a dispute-proof method of measuring the fossil fuel saved. This is often a challenge. If a fossil fuel source, say, LPG, is used to provide heat to many operation, the determination of how much fuel to apportion to the process for which solar heating is used is fraught. But the co-founder believes that this is a teething problem, which will get sorted out as the industry matures and more installations happen.

Thus, by the looks of it, ‘solar’ has just got prettier with solar-derived ‘heat’ complementing ‘electricity’. Conventional energy will have one more competitor to contend with.

Published on August 29, 2017

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