Indian Express 11.12.2010
Net zero buildings: Take no power from municipal grid
With talk much ripe about green buildings, there’s a new dimension that’s now being added — that of net zero buildings. “These are buildings that are sustainable and take no power from the municipal grid,” said Ashish Rakheja, chairman of the Green Building Committee and Technical Committee, Indian Green Building Council, as he took his seat at a national seminar on Green Buildings organised by the Indian Society of Heating Refrigerating and Air Conditioning Engineers (ISHRAE) at CII, Sector 31.
Rakheja spoke about how these can be created by using renewable resources like wind in the coastal areas and solar energy in this part of the country. “With the help of solar panels, we can make a building 100 per cent sustainable. The use of solar heaters in the city is just a step towards this,” he elaborated.
Though considered an expensive option as it takes more than 10 years to recover the installation cost, “it is now getting government backing,” he said. “As for the operational expense, that’s minimal,” he informed, adding that these are gaining popularity across the country. But then there are prerequisites to this kind of a building.
“For starters one needs to reduce the energy requirements of the building,” chipped in architect and International Fenestration Forum president Sheetal, who bagged the LEED platinum awards for green buildings. “This can be done by insulating the building with thick walls and using glass with caution.”
Sheetal recommended the generous use of glass on the north side, glass with a little shade on the south and glass that attracts only indirect sunlight on the east and west surfaces, explaining that the air-conditioning cost can be reduced this way.
She also suggested the use of white colour tiles on the roof, green electrical fittings like LED and T5 lights and occupancy censors, along with the use of autoclaved concrete blocks. “These can reduce the energy requirement from, say about 10 watts per square feet, to about two to three watts,” she said. This way the solar panel’s installation cost also comes down.
Vaneet Nanda of ISHRAE’s Chandigarh Chapter nods in agreement. “The concept of net zero building, though new, is fast catching up. Considered the highest step in green buildings because of the cost involved, it will surely reduces carbon footprints and help shape the future for a sustainable tomorrow,” he concluded.
