First month with solar panels on the działka

At first sight, it looks really good - but then mid-July to mid-August is a sunny time of year...  According to the Solis app on my phone, my eight panels generated 304 złotys-worth of electricity in their first month of operation. I would estimate that during the six-month period between equinoxes, I could be looking at an average of 250zł/month on average (1,500zł), and maybe one-third of that during the dark months (500zł), so 2,000zł revenue in a year? Don't know yet - will find out.

What goes wrong? Two days ago, I had five alerts on my app ('Grid over voltage') between noon and 3pm; the sun is shining - but it's a public holiday, and the local grid is unable to consume the power that all the local solar panel arrays in the neighbourhood is generating. This is second day it happened (first time it happened - just the once - was on a sunny Saturday evening in late July).

Since 12 July, when the meter was switched to one that reads both power taken from grid and power fed into grid, I have used 69.0 kWh of electricity and sent to the grid 449.5 kWh. That's six and half times as much generated as used; my guess - to be confirmed over the winter - is that this ratio will be reversed when the heating is on (needed to keep the house warm, dry and damp- and mould-free). At the moment, I'm using less than 2 kWh of electricity a day (mainly laptop, lighting in the evening, hot-water heater for showers and washing up, fridge, kettle and oven). With six 750W heaters, I'll be using 3 kWh an hour if they are set to full, plus all of the above, so 74kWh a day - though I doubt I'll need all that power to heat all the time to keep the house at a just-about-comfortable 19C.

So it's too early to tell, but winter no longer holds no terrors on the działka - my solar panels are like a huge stockpile of wood built up over the summer.

People might question the rate of return, but I am satisfied that I have made an investment that above all is good for the planet; I feel that I am no longer dependent on fossil-fuel (although the electricity I will have pull down from the grid come the autumn and winter will be generated by coal, at least I am paying for it with solar-generated power).

Total cost of investment: 27,500 złotys; I'm expecting a couple of thousand back from the government at some stage (a nice-to-have rather than an expectation). So payback period could be up to 10 to 12 years. Will keep you updated as more data accumulates!

UPDATE March 2023: Since the installation of panels, I have received two tranches of 2,000 zł from the Polish government, reducing my capital investment outlay to 23,500 zł.

This time last year:
Qualia meditations

This time eight years ago:
Public and private land in Poland

This time nine year:
Two Warsaw sunsets over water

This time 12 years ago:
Farewell to the old footbridge over Puławska

This time 13 years ago:
Let's ban cars with engines over 2.0 litres

This time 15 years ago:
Ul. Kórnicka gets paved over