India has made significant advances in implementing environment-friendly technologies for energy efficient buildings. The booming infrastructure developments in India demands effective implementation of these technologies to help reduce the consumption of energy and precious resources like water and soil.
Here’s an overview of the popular green building technologies in India recommended by the Ministry or New and Renewable Energy (MNRE).
CFL, solar and LED lighting
Energy efficient lighting techniques have an ample role to play in contributing towards green building technology, by cutting down energy consumption and saving money.
Using new lighting technologies can reduce energy consumption in the house by 50-75 percent, with no compromise on the quality of light, according to MNRE.
Using fluorescent tubelights and CFL lamps in fixtures provide high quality and efficient lighting. Fluorescent lights last up to six times longer compared to conventional ones. They are a bit costly, but pay for themselves by saving energy for lifetime.
Solar lights are mostly used as stand-alone fixtures, outside the home. When fully charged, the battery can power a light from dusk to dawn.
An LED lamp is a light-emitting diode product that is assembled into a lamp for use in lighting fixtures. Due to the compact size, the light output and spatial distribution of LED lights can be controlled with no efficiency loss. LED lamps have a lifespan and electrical efficiency much higher than that of fluorescent lamps as chips can emit more than 100 lumens per watt.
LED lights come to full brightness without need for a warm-up time. The LED light is more directional, emitted as a narrower beam.
Energy efficient air conditioners
AC is used to cool or heat a room. Window ACs and split ACs are used most commonly.
The energy consumption of an AC depends on the size of the AC. Select an AC that has a BEE (Bureau of Energy Efficiency) Star label. The number of stars on the BEE label indicates the efficiency of an AC. In case of the non-availability of the BEE, the EER (energy efficiency ratio) should be checked. An EER of 8 is equivalent to a 1-star BEE label.
While installing an AC, the exterior of the AC should not be exposed to direct sunlight and should be away from heat sources. Seal doors and windows to make sure that air does not escape, ensuring less energy consumption.
Solar water heating system
A solar water heater is a device that uses heat energy of the sun to heat water. A domestic solar water heater, with a capacity of 100 lpd can easily replace a 2 kW electric geyser and can save up to 1500 units of electricity a year. It pays back the cost in three to five years depending on the electricity tariff and hot water use.
The system is generally installed on the terrace and requires minimum maintenance. It works automatically and one does not have to operate any part of the system.
Two types of systems are being promoted—one based on FPC (flat plat collectors) and the other on ETC (evacuated tube collectors). FPC-based systems are costlier than ETC-based systems. To offset the initial high price (18000-25000), loans at a 2 percent are offered to users through banks and financial institutions.
A 3-4 sq m shadow-free area should be available on the terrace for installation; and provision for concealed PER pipes, with insulation for installation of the system, should be made during the construction of home.
Building integrated PV system
A PV system can be incorporated in a building as part of the building’s structure. Incorporating PV in a building helps in generating electricity at the point of demand without any extra use of land area and reducing the cooling load.
Replacing building construction material with glazing elements is helpful. In façade-integrated photovoltaic systems, curtain walls, semi-transparent PV windows and PV awnings are used as PV module as part of the building envelop. For roof-integrated photovoltaic systems atrium roofs, flat and tilted roofs, skylights, tiles, and slates are supporting materials.
There are various other renewable energy devices and systems like solar cookers, solar lanterns, solar home systems, and solar inverters that support green building concepts.