Walking into Vishwanath’s home on the outskirts of Bangalore, is an instantly calming experience. The ‘Zen Rainman’, a civil engineer by training, is a creative experimenter, who is on a quest to find sustainable living solutions that are practical and affordable enough for the masses. As a result, his house has become something of a laboratory where he tries out various technologies. There is a Chinese eco toilet on the roof next to the four different bio-zones (a wetland, a grassland, a paddy field and vegetable patch). There is a solar cooker also on his small roof and the crowd of wonderful greenery and devices makes quite a contrast to the bare concrete of his neighbours’ flat, baking roofs.
The house is built by first excavating the cellar to obtain the clay for his sun-dried, pressed bricks. The architecture of the building is designed in such a way as to enhance air-throughflow (there are no fans or air-con) and with reference to the position of the sun. Energy needs are met through PV solar panels and thermal water heaters.
The biggest success is perhaps his water conservation. Bangalore has probably the world’s most expensive water supply. All its water is pumped up to the city at altitude from the Cauvery River, using 80MW to lift more than 100 million litres of water per day. On top of this, the city and suburbs also use a combined 80 MW per day in pumping water from the more than 200,000 bore holes that descend 1250 ft down into the fossil water supply. The system is subsidised by the government in such a way that the poorest end up paying the most – they are effectively paying for the richest to waste water. This is because piped water and borehole pumped water is subsidised: householders using more than 25,000 L of water a month get a Rps 450 rebate. But the poorest cannot afford piped water or to dig and pump a borehole, so they rely on privately owned water tankers to drive up and supply water at around Rps 3 per litre.
Anyway, Vishwanath has built several different rainwater harvesting systems for his middle class suburbs as well as ones for the rural poor, which have been installed in more than 1000 villages.