> installing a couple of 300-watt panels will give savings of up to 30% on a typical household’s electricity bill, but there are lots of variables that come with that claim. It depends on which direction the balcony faces and whether the panels are shaded part of the day.
My german electricity bill is around 1200 euros a year. Sign me up for a one-time purchase of 426€ to save ~360€ every year if I had optimal conditions -- call it 50% effective and it's still earned back in under 3 years. The thing lasts, what, a decade? More?
Yeah so depends on your cost per kWh, and usage time versus production time. My 800W of balcony panels can theoretically produce 3-4 kWh per day (they peak at about 550w of actual production), but they generally produce a lot less than that. This is because my usage during production time is both less than that and also very spiky (my power usage is often 0w or 100-200w base load, with 2kw spikes as the compressor in the refrigerator kicks on, or some other device kicks on). So the savings for me isn't 3 years payoff, it's probably more like 6. But yes, these panels will product for 25-30 years. So yeah, they can pay for themselves very quickly depending on your usage patterns.
I'm in the US, and over here we also have some other complicating factors (here we have 2 sets of breakers that are 180 degrees out of phase and so the solar panels can only feed into one half of the breakers without extra complications. I only sort of understand this, someone else can explain better), so solar panels plugged into the balcony that don't backfeed straight to the grid can only cover a subset of the usage. In Germany you have 240v power so I would assume you would hit payoff very quickly.
Have to also consider the opportunity cost of that upfront cash. Those numbers sound worth anyway, but the 5 year break-even mentioned in the article is more questionable, and that's with subsidies.
(I'm too late and can't edit anymore, but I just noticed upon re-rereading that it says "couple of 300W panels" in the quote and not just "a 300W panel". My math (though done with a 450W panel for an example sales price) is likely off in the wrong direction. Sorry about that.)
> installing a couple of 300-watt panels will give savings of up to 30% on a typical household’s electricity bill, but there are lots of variables that come with that claim. It depends on which direction the balcony faces and whether the panels are shaded part of the day.
My german electricity bill is around 1200 euros a year. Sign me up for a one-time purchase of 426€ to save ~360€ every year if I had optimal conditions -- call it 50% effective and it's still earned back in under 3 years. The thing lasts, what, a decade? More?
(Price taken from https://kleineskraftwerk.de/products/kleines-kraftwerk-gitte... for 450W, first one I could find from some review site.)
Edit: figure corrected for not using the tax rebate that it apparently advertised with