By Renu Kakkar
In the last 370 days, I have offset 2.13 tons of carbon, which is the equivalent of 55 trees and driving a car around for 2,25,000 km. If combating climate change was an Xbox game, consider it lost. This game can only be won by having one’s own skin in the game. If none of us has skin in this game, it is pre-ordained that every one of us will be at the receiving end of what climate change will bring home.
The biggest challenge of sustainability is changing the mindset to what ‘I need to do’ from what ‘the world needs to do’, ‘we as a society need to do’ and ‘corporates need to do’. In 2017, going solar was the most important lifestyle change that I made because with it, I really brought my own skin in the game, incurring a huge investment that would have bought a car! This after I had made a big investment of changing every light to LED and every fan to ones using Brushless Direct Current Motors which really pinched my pocket.
Whenever we are on a holiday, my home is producing and exporting power for others connected in the electricity grid to use. My reducing carbon footprint as per the USEPA Clean Energy Equivalencies calculator is exciting. This sketch below is how the 2.2 kWp on grid solar rooftop PV (SRTPV) System using micro-inverters that I have installed at home at an expense of Rs 2.6 lakh looks like –
My house generated 3030 units and this solar power generation was able to offset majority of my own consumption of 4300 units from August 2017 to July 2018. I would have paid close to Rs 25,000 in electricity bills for using 4300 units of power but because i was producing solar power I have actually saved Rs 16,000 -18,000! The most visible change is in the monthly bills that I pay now – a drop by 75%. In July 2018, the 12th month since commissioning my solar power system at home, I paid an electricity bill of just Rs 400! I would have had to pay a bill of a little over Rs 2,000 because the total consumption inside the house was 315 units but because my solar system generated 230 units, I paid for far less units of electricity.
At this rate, the solar power system that cost me Rs 2.6 lakhs will pay for itself in the next nine to ten years. Considering an increase in electricity tariffs at the rate of 5%, by end of 25 years, my savings would be around Rs 8,07,444. So with an initial investment of Rs 2.6 lakh for the 2.2 kWp saves about Rs 8 Lakhs by end of 25 years. Not too bad huh!
Here’s the “how to” of it …
Power Panels – They are installed on the roof. You can have a tiled roof or flat terrace or a mix of both like I had, i.e. 200-250 sq ft of flat roof and 88 sqft of the tiled roof facing North, South, West and East. We installed 7 Poly Crystalline Panels, each nearly 2 metres long, 1 meter in breadth and 0.42 meters in thickness and weighing 22.5 kgs. The Brand is “Waree” made in Surat and coming to us through Pondicherry.
Microinverter – They go behind the panels depending on what system you choose. I chose a certain system and installed 7, one per panel. They are inverters mounted behind the panels to convert the DC current produced by Panels to AC current as well as synchronize the output of solar with the Grid Voltage and Frequency. The brand is Enphase Energy.
Gateway/ Monitoring hardware – It’s a communication device installed next to the meter that transmits information, about how the solar plant is performing, over the Internet to a cloud-based online portal, where I can remotely monitor the system. The device has an inbuilt storage system which will store the data of the rooftop system if my Wi-Fi is down and once it’s up it sends the data back to the Online Portal. So, at all times I have a record of how the system is functioning. EcoSoch as my installer also gets to see and responds before we find an issue.
Mounting Structure – It is used to place the panels at the right angle to catch the sunlight. Mounting structures on the flat roof weigh 30-35 kg each. On the tiled roofs, they can be grouted to the RCC roof below the tiles for each panel.
AC side Electrical accessories – In our case, I needed 7
Earthing kit – I needed 1
Taxes – Last year there was a VAT exemption for panels and micro inverters
Others – Basic Surge Protection devices and Manual Disconnect switches near the meter. Then there was Installation , Permits and Commissioning costs.
Electricity Meter – Before installing the solar roof-top, my meter was a unidirectional meter which calculates only import of energy from the grid and I paid for what I used and if someone messed up with the reading I paid more too!. After installing the solar roof-top system, I have a bi-directional meter since my house now exports energy as well as imports energy and can read it myself by learning it from here . We have a meter room in the garage.
Billing – The DISCOM (Power Distribution Company), in my case Bangalore Electric Supply Company continues to take readings on a monthly basis for generating the monthly bill. It calculates both export and import from the Bi-Directional Meter, and the billing is based on the net amount of export or import (Export-Import or Import-Export, whichever is higher. If my export is greater than import, I get Rs. 7.08/unit for whatever my excess export is i.e.,[export – import]. If my import is greater than export, I pay the bill for the excess consumption i.e., [import – export] based on the tariff.
There will be no drilling of the terrace so, there is no question of seepage and water leakages on the roof. The support structure is of aluminium which doesn’t rust. No painting or strengthening is needed throughout its life period. Wind Speeds of 150km an hour are no issue. Maintenance during non-rainy months is cleaning by water. If I want to dismantle because another floor is to be constructed, I can do that as there is no permanent grouting on the terrace floor. All equipment supplied has warranties. It took me about four months, starting from the date of the first meeting a company we instantly liked, EcoSoch Solar, in April 2017 at one of their college, community, corporate awareness events, and after rejecting quite a few. The plant was finally commissioned on 25th July 2017. The actual time to put the plant up was just two days, a weekend during which they kept moving from roof to ground. The team was so dependable that I did not have any security concerns and they were so clean that there was no mess left behind.
Before going solar, you will need a rooftop 80-100 sft of shade-free area to install a 1kW solar plant. You should be prepared to sign many and I mean it, there are many necessary approvals for installation and commissioning. You should provide some space for placing the inverter and data logger that will be connected to your home wi-fi and the company will do structural earthing which protects from leakages, fire hazards, personal safety like shock due to leakages.
When there is a power cut, the system does not export energy to the grid as it will cause a shock to anyone working on the line through a safety feature called anti-islanding which ensures no energy is generated. Watch this video on how everything works
You should know that your linemen who records energy consumption every month to generate the electricity bill is not trained to read a bidirectional meter so electricity bills may stop. We did not get any bills from August to December 2017. They came in January after we wrote to the MD of Bescom. And earlier this week, we got a whole year of billing, an amount of Rs 10,000 odd with a notice of one day disconnection if we did not pay up right away!
Just understanding this process of installing a solar plant can send you into a snooze! Not a single person in my family or circle of friends have generated solar power at home. Not a single one. Everyone seems to be indulging in appreciating the impact of solar but none of them seems to be wanting to implement it. So find a company that are able to explain what they are doing transparently and with assurances, keep rejecting till you find the right one. You should research a hybrid technology in your city if you want to power equipment in the house during a power cut.
I am a staunch believer that the climate is changing and it will impact everything – to what we eat, how we live, how we die. I believe that all right-thinking people should speak out about it loud and clear. This means not just liking social media posts or speaking about the weather but actually putting actions, time and money where their mouth is. We must all transcend to living sustainably because we cannot afford or really combat climate change. Imagine this – you cannot generate water (H2O) for your household even if you have access to Hydrogen and Oxygen but you can generate electricity from the sun. If you travel by air as much as me then you can offset your carbon footprint and be less of a burden as a citizen. And that’s why you should do it.
Renu Kakkar is Director, CSR & Communications, Apeejay Surrendra Group. An LSR and IIMC Alumni , she is on the Advisory Council of WLCI – School of Digital Media and Communication and is co-founder of a not-for-profit company that creates awareness about the need to enhance the quality of services across all major activities covering day to day living and economic life.