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Construction : Interaction | March 2016 | Source : CW-India

The maximum potential for saving electricity is in buildings

- Dr Vishal Garg, Associate Professor & Head, Centre of IT in Building Science, IIIT-Hyderabad
With the ever-increasing requirement of energy and power shortages in our country, came the need to identify a solution, which would work towards utilising power efficiently and saving energy. In 2007, the Energy Conservation Building Code (ECBC) came into effect to promote energy-efficiency in the building sector. Dr Vishal Garg, Associate Professor & Head, Centre of IT in Building Science, IIIT-Hyderabad, who heads the Centre for IT in Building Science, has based his research and area of expertise in the field of energy simulation and lighting, and played a pivotal role in the rollout of ECBC. He shares more in conversation with SHRIYAL SETHUMADHAVAN.

How do you view the demand for power in India and what is driving the need to conserve energy?
Buildings are the major consumers of electricity and, according to estimates, building stock is going to double in the next 15-20 years. With this, there will be a huge demand for energy. Hence, it is important for supply to be in line with increasing demand. Also, in developed countries, if energy consumption in buildings is reduced, probably one generation unit is shut down. The interesting thing about India is that if I reduce my energy consumption, I don´t install one generation unit. So, if we are able to save more energy, the gap can be reduced, as would be the pressure to install more generation units. The maximum potential for saving electricity is in buildings.

What does ECBC primarily comprise?
ECBC has five areas of focus. The first is the envelope, and the code focuses on how its components of walls, glass, roof and shading elements can be made more efficient.

The second is controlling and saving energy through lighting. The third and major area is air-conditioning, which includes systems, fans, pumps, chillers, etc. The fourth is power distribution - how efficient is the distribution of power, transformer, motor and all electrical aspects? And the fifth is the hot water aspect - are we using wave heat or solar energy to generate hot water; if we are using boilers, how efficient are they? As for compliances, ECDC has two approaches of ´prescriptive compliance´ and ´performance method´. Prescriptive compliance clearly gives specifications of all the aspects of buildings. This depends on climatic conditions and building usage, without much flexibility. In the case of the performance method, the logic is simple: Show the energy consumption of a building and proof of the energy being saved. So this is all performance-based. We simulate the building, which is designed as per prescriptive specifications on computer software and find out how much energy it will consume. This is called the standard case. Then, we simulate the building proposed to build and discover how much energy it will consume as per the proposed specifications; this is called the proposed case. If the proposed case energy consumption is less than the standard case energy consumption, it means my building is good enough and will comply with the code.

Is the ECBC code mandatory nationwide?
ECBC is or was developed by the Bureau of Energy Efficiency, Ministry of Power, in 2007. But each state had a choice to take it as a standard and make it a code. When a building is being granted permission, many aspects are taken into consideration. They check if it complies with the bylaws, the fire code and others. So, this is one more check to ensure that the building complies with the energy code. Rajasthan was the first state to notify it, and now eight to nine states have made it mandatory. However, in some cases, it is mandatory on paper, but not much is being implemented.

Please introduce us to the innovations and technologies that go into creating better energy-efficient systems?
First, we are forgetting our traditional construction style, suitable for our climate. Even before innovations and technologies, we need common sense. If we follow the architecture followed in the West, by making big glass boxes, not shading our buildings, etc, we are obviously in trouble.

On the contrary, if we go by the basics of architecture and design as per climate and climatology, half the battle will be won. And then, when we need to improve these designs, the need for technology steps in. Shading, for instance, is most crucial in a building because the solar wave in buildings in India is the biggest contributor to the air-conditioning load.

So here, the orientation, external and internal shading, glass properties, etc, play an important role. The façade is the first line of defence for the building. By improving the façade, we can stop heat from entering the building. And if the heat still enters the building, we require more efficient air-conditioning and lighting systems.

Cool roofs also play a role in conserving energy...
The cool roof is not an innovation. These were with us hundreds of years ago. And today, when energy is becoming a problem, the concept of a cool roof is coming back to us as an innovation, and we are getting new products like coating, films, tiles, our traditional whitewash, white ceramic tiles and some others. My quick analysis is that coatings don´t seem to work well, the way we construct and use our roofs. In India, roofs are not inaccessible, and we have flat roofs instead of sloping ones. This, at times, leads to water collection on the roof and the coating gets damaged. People walking on the roof or dragging equipment can also damage the coating. According to my preliminary research, it is better to have tiles. You could use white ceramic tiles; they will last for five decades. You will have little maintenance compared to coatings and membranes, which are delicate and need maintenance every five to seven years. You have to recoat it and they are expensive. So I would love to go back to the basics and the knowledge that we had and applied ages ago.

Are builders and developers open to adopting these methods and techniques to conserve energy?
I have found builders very receptive. If an IT company is developing its own building, whatever money the owner spends, he will get the benefits in terms of energy savings.

So the spend might be Rs 10 crore, but there would be a yearly saving of Rs 5 crore. So, this could make business sense. But for the builder, if he spends Rs 10 crore, the tenant will get the benefits of Rs 5 crore every year. So this is called flip incentive. In this scenario, the builder does not want to spend the money for the user to get the benefit. However, if things are made mandatory or a law is passed, builders are willing to adhere to the law. But for a builder, the law should be stringent where it is applicable to all; it should be simple with no multiple interpretations; and this should not add to the list of permissions.

What is the way forward for India in the area of energy conservation?
In India, buildings are not seen as domains. We have several domains such as architecture, civil, mechanical, electrical, etc. With buildings having maximum impact on energy consumption and global warming, the time has come for us to start looking at buildings as a separate interdisciplinary area; the government should help educational institutes take buildings as a specialisation.

We need a long-term sustained effort in R&D, so that we do solid research and emerge with efficient building designs. Interdisciplinary research is important as the world is moving towards zero energy buildings now - buildings that produce their own energy. And we have to take a leapfrog jump here. Today, many villages are connected and many don't have grids. Instead of putting up the grids, we can go solar and do efficient buildings. Thus, there is a great opportunity for our country to go to the next level of technology and not follow the path the developed countries have followed.

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