Micro-Inverters vs Off-Grid Inverter

[J1mbo]

I'm looking for a PV system that can also run off-grid and with a small generator attached. The Sun 8k hybrid seems to do everything I need. But the solar companies are telling me that micro-inverters are the way to go.

 

In the end, are the advantages of the micro inverters worth the extra cost?

 

The idea of a single inverter which can take PV/Grid/Generator inputs and charge attached batteries is pretty attractive, not least because with 8kW output it will also run my heat pump.

[dpmiller]

can a gennie- specifically the more efficient inverter ones- clamp the output of the solar inverters sufficiently to stop overvoltage trip outs?

[SteamyTea]

Does the module array have shading issues?

 

Also worth looking at the efficiency distribution, it is not often that system work anywhere near maximum output, most of the time they are below 25% of the name plate capacity.

Would be better to add an extra module or two if you can. 

[PeterW]

34 minutes ago, J1mbo said:

The idea of a single inverter which can take PV/Grid/Generator inputs and charge attached batteries

So that’s two components not one, unless you’re talking about a power wall that will charge batteries from 230v..?

 

8kW on a heat pump ..? Is that 8kW input ..?? Would have thought it was 8kW output with about 3kW max input so if you then add in a baseline load you want 5kW to cover most off grid eventualities…?

 

The Victron Easy Solar II does everything you want in one box, including managing batteries, UPS/grid, solar and other stuff but they are just about change of £3k when you add the connectors and ancilliaries to it. 
 

https://www.batterymegastore.co.uk/product/victron-energy-easysolar-ii-48-5000-70-50-mppt-250-100-gx-pmp482507010/

 

 

[J1mbo]

Thank you @PeterW - much appreciated. I don't mind having separate batteries. The ASHP is 5.4kW max draw (20A) and 12kW output. Those boxes look very interesting.

[PeterW]

So the nice thing about Victron stuff is it plays nicely with other components - you can essentially stack them to give more capacity etc. and they sense each other. They do a range of mppt charge controllers and then grid tie (or shore power) inverter controllers or battery chargers so you can literally plug and play as they use VE-Bus to communicate and you add the components you want. 

[sanch3z]

On 22/02/2022 at 10:06, PeterW said:

So that’s two components not one, unless you’re talking about a power wall that will charge batteries from 230v..?

 

8kW on a heat pump ..? Is that 8kW input ..?? Would have thought it was 8kW output with about 3kW max input so if you then add in a baseline load you want 5kW to cover most off grid eventualities…?

 

The Victron Easy Solar II does everything you want in one box, including managing batteries, UPS/grid, solar and other stuff but they are just about change of £3k when you add the connectors and ancilliaries to it. 
 

https://www.batterymegastore.co.uk/product/victron-energy-easysolar-ii-48-5000-70-50-mppt-250-100-gx-pmp482507010/

 

 

sorry to hijack. I'm starting out and looking at victron as they review well, and have been around a while. I can see advantages and disadvantages of one box does all:

 

Advantages
- Compatability

- Less companies to deal with

- Easier to fault find

 

Dissadvantages
- Can be more expensive than seperates
- If one thing breaks the whole thing breaks

- No ability to swap out failed element or upgrade

 

Now the warranty of 5 years is ok, but if it only lasts that long than that's £650+ a year. Does this represent good value? I know nothing about PV equipment and manufacturers so might need a reality check. Happy to have one