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by zhivota 38 days ago
Nope but in a different market so makes sense, those are probably pure grid tie inverters, which I don't have a lot of experience with because it's not commonly used here. I do see the EG4 hybrid has a similar ratio (we have the same tech here under the Luxpowertek brand).

Even without a battery people usually choose hybrid, which can function on and off grid.

Also to be honest I'm mostly looking at larger inverters so maybe that colors it. Not many users here need 24,000 watts continuous outside a commercial context, for instance, so an inverter with that as an input but 12,000 watts continuous AC output doesn't seem weird since part of the 24,000 watts DC can be sent to the battery.
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margalabargala 37 days ago
Ok, yeah that makes sense. Over here people usually get direct grid tie inverters, and if there's no battery, there's no reason for a hybrid inverter. The cheapest way to do it is panels -> inverter -> grid. No cutoff switch, so the inverters stop functioning if the power goes out.

Then it's just a race to pay back the panels, which are most of the cost, so undersizing the inverter is wasing energy and leaving money on the table.

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spockz 37 days ago
On my case I have 4500Wp of panels. The inverter is sized at 4200W. The next step up 4800 or 5200 was twice as expensive adding about €600. Not sure if I ever would have made that back. I hit the maximum only a few weeks in spring.
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margalabargala 37 days ago
Let's say your panels could produce 95% of nominal, 3 hours a day, 3 months of the year when the sun is in the right spot. That's 4275W, or 75 over.

0.075 * 3 * 90 is 20kWh you're leaving on the table per year. So yeah the payback time for the more expensive one would be never.

I'm seeing price differences from 4200W to 5000W inverters be more like 10-70€ though:

https://www.alma-solarshop.com/10-solar-inverters?q=Inverter...

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spockz 36 days ago
This was in 2019 though, prices were further apart back then. But maybe I just looked at the wrong shop as well.
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zhivota 38 days ago
Also just as a follow on my assumption is it's much easier and cheaper to scale the DC side since it's often at the 400-500v range (for example 10 panels in series with open circuit voltage of 49v and operating voltage around 43v) vs the AC side in the 230v range, since resulting amperage is half. So that may account for the ratio.
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