A year of using grid connected solar power plant

It’s been well more than a year since I got my solar power plant installed on my rooftop back in August of 2020. Recently, I noticed that the 3kW plant produced 17.9 kWh of electricity in a single day, setting a personal best record for itself. Wondered why don’t I review how its been doing for the past year, check how it is performing and share it so that at least few more will start to adopt clean energy.

Installation

Before we get to the installation part, I would like to make it clear that the installation I have is an On-Grid type one. Meaning, I do not have a battery bank setup which stores the energy generated by the plant and the appliances at home don’t feed off the battery bank directly. That kind of a setup will turn out to be expensive to install, complex to design and hard to maintain.

On the contrary, the installation is an On-Grid one, which means the plant is connected to the grid directly. This means two things primarily

• Whatever energy that is being produced is exported to the grid. You don’t need to have a battery bank at home to store the energy. Because energy is exported, there is no wastage in terms of excessive energy produced.
• If there is a power cut, there is a power cut. As there is no backup storage, appliances at home can’t work and it’s not easy/possible to route the solar energy directly to the appliances.

Key points related to installation as follows

• I outsourced the installation to Zolt Energy. They took care of everything starting from net meter approval to getting the plant installation done.
• It’s a 3kW plant. The plant capacity cannot be more than the contracted load on your existing meter. You can find the contracted load value on your electricity bill.
• The entire thing costed me approximately 1.3 lakhs back in 2020. That is excluding the government subsidy which the service provider (Zolt) gets directly from the government. From your pocket, 1.3 lakhs is the final amount you’ll have to pay. There are other installation providers which do it for less but I like the service offered by Zolt.
• By default, they install the panels at ground level on the terrace, if you want to save the walking space, an aluminium frame has to be installed, it will cost an extra 10k.

Lastly, I live in Hyderabad, India. So these may be different in other states.

Before Installation

Our electricity consumption used to depend on season. It used to range from anywhere between Rs. 1000 and Rs. 6000 .

Billing history from TSSPDCL app

After Installation

Yield over last year has been between 300–400 units per month.

Number of units generated monthly in the year 2021

Yield depends on lot of obvious factors like season, weather etc. One important thing is that if you are living in an area where there is lot of dust, a layer of dust accumulated on the panel can affect the output. Ensure the panels are cleaned every once in a while.

With respect to the electricity bill, I have been paying less than Rs. 100 on an average since the time the plant was installed.

Payment history for the last 11 months

Though the units billed are 0, there are some charges levied upon by the TSSPDCL which results in that Rs. 75–80 invoice being generated monthly.

Comparing that with the amount I used to pay before installation, I am saving approximately Rs. 25–30 thousand per year at a minimum. I am effectively looking at a ROI period of approximately 5 years.