christoff83
New member
Hi all,
As with many previous threads around this topic on this forum, and other forums, I’m wondering whether to install 5kw or 8kw inverter. Having read quite a few threads and articles, I want to try summarize my view on it.
For me, the top key takeaways from these discussions are:
So two questions for the audience:
Any other comments welcome.
Cheers
As with many previous threads around this topic on this forum, and other forums, I’m wondering whether to install 5kw or 8kw inverter. Having read quite a few threads and articles, I want to try summarize my view on it.
For me, the top key takeaways from these discussions are:
- Understanding the difference between inverting capacity and passthrough capacity. When an inverter is advertised as 5kw, typically that refers to its continuous “inverting capability” meaning – to me – that while eskom power is off, you cannot carry more than 5kw load; or even while power (eskom) is on, you cannot contribute more than 5kw from your solar array or battery.
- BUT, a 5kw inverter does not mean that you are overall limited to run your house at a maximum of 5 kw all the time. I see many manufacturers refer to a continuous AC pass-through power or current. Today I’ve seen a few as 50A which – again, to me – means 230v AC @ 50A means around 11.5kw load you can carry in your house WHERE a theoretical maximum of 5kw could come from your solar array or battery.
- Most high-quality inverters are informally known as “true hybrid inverters” which means in the above scenario, your house can run up to a total of 11.5 kw where the first 5kw will come from your inverting capacity (solar or battery) and the shortfall from 5 to 11.5 will be “blended” from eskom. This of course assumes eskom is on and that you also have 5kw available from your solar array or battery.
- Some people prefer to parallel two 5kw’s instead of going for a single 8kw because:
- Lower entry cost (you can start with one 5kw and add another later)
- Redundancy. If an inverter fails, chances are you’ll have another while repairing…
- More MPPT’s with added capacity and flexibility (depending on the brand).
So two questions for the audience:
- Would you agree / disagree with my key takeaways above?
- In light of the above, assuming it’s more or less correct, is there anyone who implemented a 5kw inverter who wished they had gone for 8 kw or anyone who had gone for a 8kw and realized that a 5kw would have been sufficient?
Any other comments welcome.
Cheers
