Balkonsolar - year two in review
Thomas Hampel
2 January 2025It's been two years ago when I installed two solar panels on my balcony to produce my own power.
I've already blogged about it at length last year.
Now another year has passed and I'd like to review it again because some parameters have changed.
1. The cost of power per kW has reduced from € 0,49 to € 0,35 per kWh
2. Panels are now positioned at an angle instead of just hanging at 90degrees
3. New solar panels are cheaper than ever before.
so lets take a look 2024.
I've done a first assessment exactly one year ago, so now its time to review the second year of running my own mini solar power production at home.
Following are the plain unfiltered figures:
Produced : 552,53 kWh, so 121,81 kWh more than last year.
I've returned 109 kWh to the grid (for free) due to producing more than what I have used, mainly because I was on vacation away from home.
At a current price of € 0,35 / kWh it results in savings of € 193,39 for 2024, compared to € 210,62 for 2023
This is about 17 Eur less than last year where power was more expensive a year ago : € 0,49 vs. € 0,35 / kWh.
Also this is indeed a high cost per kWh compared to € 0,32 / kWh which you could get with a new contract - however, last year it was the cheapest option for us.
I am including the energy I have returned to the grid worth € 38,15 in my savings calculation because it was on me to use it.
Here is the chart showing power production over the course of the year.
In this year, the month of August seemed to be the best month, shortly followed by July - both months providing a good amount of sunlight and power output.
When putting 2023 and 2024 side by side, you can see what a difference it makes to mount panels at an angle.
I have to admit, I have certainly not mounted my panels in the most optimal position. However, it really makes a difference!
Overall a 28% more output from exactly the same modules.
Ok, great - now what's next?
UPGRADE! This year the legal situation changed in Germany. It is now allowe to run with an 800W inverter while I'm still using the basic 600W inverter.
I already bought the new inverter, but have not found time to do the upgrade. Overall I'm not expecting a huge power boost, but a small 10% to maybe 20% imporvement during peak season in summer.
TCO
Price for new solar panels has dropped to <60 Eur / piece for a 450 Wp panel, e.g. Trina Solar.
EUR 110,- for 2x Panels (€ 55,- each)
EUR 110,- for 1x Hoymiles HM-800
EUR 80,- for panel mount/equipment
EUR 50,- for some 5m solar power cables,adapters and other small parts
= EUR 350,-
Given current figures, the entire investment would have already payed off in just two years!.
Just because I bought my equipment at a slightly higher price it will take another year for me to get a return on invest.
Conclusion:
Is it (still) worth it ?
Need to repeat my previous statement from 2023 : Absolutely YES YES YES YES!
Even at current energy prices and prices of new solar panels you'll have a return of invest in under two years.
That is comparable to an interest rate of >50% - where on earth do you get that for your bank account?
My advise:
Dont wait, START NOW and install as many solar panels as you (leagally) can.
This year I helped two more friends with buiding their own "Balkonkraftwerk".
Tagged with: Solar