17-Mar-2020 : Pavitra Sriprakash, Director and Chief Designer at Shilpa Architects Planners Designers writes a weekly column on Sustainability for The New Indian Express titled “ECOLOGIC”. This week she writes about making a switch to rooftop solar.
Full article below: (Also available at The New Indian Express Website)
It’s time to switch to solar
The mercury is rising! Instead of equipping ourselves with watermelons and air conditioners to stay cool, why not consider going solar this summer? Renewable solar energy is a state-wide focus and Tamil Nadu is striving to make solar energy available, accessible and affordable to all. It is projected that the state will have an installed solar energy generation capacity of 8,884 MW by 2022. Of this target, 40 per cent is expected to be met by consumer scale solar energy generators, which are essentially self-owned, and operated solar PV systems, which are part of rooftops of individual buildings.
This makes any available rooftop viable for solar energy harvesting! As an added incentive, corporations, municipalities and local urban bodies will provide property tax abatement to domestic building owners who install consumer scale solar energy systems. In order to understand consumer-scale solar energy, it becomes vital to understand what is popularly called “net metering”. All of us are familiar with our regular electricity meters; in the case of solar power, the existing meter needs to be replaced with one that measures both the energy import (from the grid to the consumer) and energy export (from the consumer to the grid). These meters are known as bidirectional energy meters or import-export energy meters.
The rooftop solar panels harness energy from the sun and convert that to an AC (alternating current) by a solar grid inverter. The output of the solar grid inverter is connected such that the electricity flows to the loads of the buildings (lights, fans, appliances etc.). If the solar energy produced is more than what the building loads consume, the surplus energy will automatically be exported to the State distribution network (the grid). If there is less solar energy than what the building requires, the shortfall will be drawn from the grid (energy import). This ensures constant electricity supply to a home even on days when harnessing solar power is a challenge due to cloudy skies, etc.
As an addition to the previous policy of 2012, the current draft includes “group net-metering”. In case of excess energy produced by a building rooftop, the surplus can now be exported to the grid and adjusted in any other service connection(s) of the consumer within the State of Tamil Nadu. This will maximise the utilisation of rooftop space for solar by those with multiple buildings and service connections. Similarly, for those who do not have rooftop space for a system, a “Virtual Net Feed-In” is possible. Through this system, one can be part of a collectively owned solar system.
All energy produced by the system will be fed into the grid through an energy meter and the exported energy is credited in the electricity bill of each participating consumer of the collective. So, whether you are thinking about it or not, solar power from your roof or your neighbor’s roof is now possible. So go online, learn more and become your own clean green electricity generator today! Going Solar is a great way to beat the rising mercury and save money at the same time.