To India, the concept of Zero Energy or Net Zero Buildings might sound alien, if not absolutely bizarre, considering that the first of its kind in India was just inaugurated only in 2014. To swallow the idea wholly, one must first know what Zero Energy Buildings (ZEBs) are all about. Imagine the whole building’s needs being powered by renewable energy produced and utilized within the premises of the building, without having to depend on the grid for electricity and without having to worry about high energy consumption, the electricity bill or the amount of greenhouse gases that are being emitted. ZEB is such a solution.
It is a building whose total energy consumption on an annual basis is roughly equal to the renewable energy produced within the site. On a practical basis, it may not be possible to achieve this completely, since there are cloudy days, rainy days and dark nights when solar panels will not be able to do their job and the buildings have to be dependent on the grid. Even though a zero energy building’s efficiency depends largely on the electricity usage patterns of its dwellers and the climate, the key determining factor is its design. Some of the designs adopted by ZEBs are: replacement of incandescent lights with LED lights, technologies to enhance maxmimum utilisation of daylight in order to reduce the dependance on artificial lighting, utilizing thermal energy produced by refrigerator exhausts, ventilators, body heat, etc.
In India, the Indira Paryavaran Bhawan has been functional since February 2014, with the incorporation of Solar Passive Design and energy efficient building material. It is the first Zero Energy Building constructed in India. The project has already won 2 awards: an award from Adarsh/Griha of MNRE for exemplary demonstration of Integration of Renewable Energy technologies in 2013 and a 5-Star Green Building Certification by GRIHA under MNRE in 2014.
The building has features such as effective ventilation, utilization of 75% of natural daylight, easy access for differently abled persons and innovative air conditioning by convection currents instead of air flow through diffusers, which contributes to about 40% energy savings. It hosts India’s largest rooftop solar system for multi-storied buildings with a capacity of 930 kW peak power. The physical structure employs green materials such as renewable bamboo jute composite materials and high recycled content for construction. Recycling of waste water through a sewage treatment plant, use of plants with low water demand in landscaping, rain water harvesting, use of geothermal cooling for HVAC system and low discharge water fixtures are some features incorporated in order to reduce water consumption.
The building is an earthquake-resistant structure with more than 50% area outside the building being a green area. It has a robotic parking system that can accommodate 330 cars. A thin-client networking system instead of desktop computers has been provided to reduce electricity consumption.
Such a building is a remarkable example of utilization of technology in order to accomplish economic savings as environmental sustainability. Even though ZEBs have high capital costs and very few designers have necessary skills or interests to build such structures, they ensure a lower cost of living without compromise to comfort, higher energy efficiency and independence of owners to future increase in electricity prices. Despite being highly dependent on the presence of sunlight and wind, among other environmental factors, they are the future for India, and the world itself, in terms of efficiency, affordability and sustainability.
About the Author
Shreya Dutta is a Master’s degree holder in Power Engineering from Nanyang Technological University, Singapore. she had brief experiences with photovoltaics, electric cars and building energy management, all methods of utilizing electricity through sustainable and economic means after her bachelors degree. Shreya is currently working in Energy Research Institute @ NTU (ERI@N), Singapore for the Sustainable Building Technologies team.