05 September 2017 14:56:41 IST

Heating is becoming pretty cool

Solar and heat pump technologies are gaining ground and offer great entrepreneurial opportunities

Oxymoron it may be, but it is true. Heating is becoming pretty cool. In the war against fossil fuels and expensive energy, a few devices have come in very handy today.

When you check into a hotel and step under the shower or dive into the pool, you expect the water to be hot. The laundry in the hotel needs a gust of hot air to dry clothes. An automobile company needs heat to dry paint, an agriculturist needs warm air to dry his produce.

These are ‘low heat’ activities. The temperature involved is never more than 90 degrees Celsius. Today, in these sectors, fossil fuels such as furnace oil or kerosene are burnt to produce the required heat. But soon that will be passé.

Greener options

Now, it is time to say ‘thank you very much and goodbye’ to fossil fuels, and welcome a few other green technologies.

India is now looking at a completely new deal for industrial heating, one that will be both clean and cheap.

Specifically, two separate green technologies have entered the business and are making steady inroads — solar and heat pumps. Interestingly, both provide ample entrepreneurial opportunities.

At one end, solar heating is no big deal. All you need is two thick sheets of glass stacked up with a few inches gap between them, so as to trap air. Provide a tube to drain the hot air, and the device is complete. Paint the glasses black, you will absorb more heat. Put the contrivance on the terrace and you can keep sucking out the hot air and what have you? A steady flow of hot air that you can use to dry a painted surface or a tray of cut fruit.

Economic, environmental benefits

While such a device will give you temperatures up to 70 degrees, you could improve it to generate more heat. At the higher end, for higher temperature industrial applications, there are systems that use large parabolic mirrors to focus heat on a point containing a “thermic fluid”. A Delhi-based company called Megawatt Systems has been providing such heating systems to industries. With such systems you can achieve temperatures of about 150 degrees Celsius.

It is estimated that India’s solar heating market is about 20,000 MW. Against this, the existing capacity is, hold your breath, 20 MW! A thousand-fold increase is in the offing.

Companies such as Wheels India, Sona Koyo, Parle, Himachal Pradesh Milk Cooperative, Synthokem and OVC Glass Fibre, have replaced their existing heating systems with solar heaters. Their numbers are showing huge economic benefits (apart from the hidden environmental and climatic upsides.) Now, as is typical in the industry, once a few pioneering companies take the plunge and demonstrate success, all other companies will follow in a herd.

Corporate India is at that stage. Solar heating is fast becoming the norm. The level of fossil fuel avoidance is unimaginably high.

Heat pumps

However, alongside solar, another technology is emerging — heat pumps. These are devices that suck up atmospheric heat, rather than the sun’s. You might think that the ambient atmospheric temperature would not generate that much heat, but these heat pumps actually do, because they are designed to do so.


A heat pump typically starts with compression of a certain gas. The compressed gas is allowed to decompress suddenly — or expand — which means it drops temperature drastically. This ‘cool gas’ is passed through a pipe that is exposed to the atmosphere. It absorbs heat. Then it is piped to the compressor — the compressing imparts the gas both pressure and temperature. At this stage, the gas is pretty hot. A ‘heat exchanger’ takes away most of its heat and the gas then goes through de-compression or expansion, to become cold again. Thus, in such a cold closed loop, the gas keeps getting cold and hot and its heat is always siphoned off and used.

Of course, you would need electricity for the compressors to work. But, using a little bit of electricity instead of tonnes of fossil fuels is smart. Smarter, if you generate that electricity using solar panels.

Room for more players

Heat pumps have been around for decades in Europe, but in the last two-three years, they have been making a mark in India. Companies like Bosch sell large-sized heat pumps to big hotels and process industries, while small companies, such as the Chennai-based Aspiration Energy, service the low-heat uses.

People like Siddhart Malik, founder of Megawatt Solutions, and Bhoo Thirumalai, the man who started Aspiration Energy, are now getting pretty busy — and rich too. There are estimates that the addressable industrial heating market in India is $10-billion big, at a very conservative estimate, so there is a lot of room for everybody.

What is also helping matters is the advent of the ‘opex model’, where companies like Aspiration Energy install the equipment at the customers’ premises at their own cost, and sell only the heat. The trick here is to be able to measure the heat accurately, in a manner that does not give rise to disputes. The ‘opex model’ is getting very popular in electricity — a solar company would install a rooftop system at the customers’ factory and sell only the electricity under a ‘power purchase agreement’. Similar arrangements for selling ‘heat’ are emerging.

Solar heating and heat pumps have incredible potential to change the game. And things are beginning to hot up. Just the right opportunity for a start-up. Want to give it a shot?