Preferences when selecting PV inverters

Jonason

What are your preferences when selecting PV inverters? Is it based on price, efficiency, or simply recommendations from installers?

micks_address

Well there's a couple of considerations

1) is it ac only or DC or hybrid?

2) what batteries are compatible with it?

3) what's the products eco system like for software, other components like car charger, solar diversion

4) what power is it? Max for basic esb connection now is 5,kw?

5) what throughput can it charge and discharge batteries at?

7) what temp does it d rate at. Is it suitable for the location you are installing.

8) what load can it cover and for how long. Battery plus solar etc can it cover higher watt appliances for what length

9) what EPs/backup power supply capabilities has it..

That's all I got for now

curioustony

10) how easy is it to get access to historical data, can you see data per string

11) can you schedule charge from grid and discharge to grid. Can you do this using automation such as home assistant

12) does the inverter require a grid connection to start (long power outage with changeover switch scenario)

DC999

I'd suggest it's much less complex. Get a few quotes and then post them on the quotes thread with the details of the inverter make and model. I got 'analysis paralysis' when looking at quotes and it stopped me progressing. Once I got over that I could pick an installer based on quotes. I'm live now over a year.

If you don't need a battery (which I'd suggest you don't need now that FIT is paying 20c+ per kWh you sell back to the grid), then you just need a standard inverter. Not a hybrid one (which is the battery ready type).

Efficiency wise, there is no difference. Or it's so low as to not matter. If you got 1 extra panels it would add wayyyyy more efficiency to the system than a rolls royce inverter (which you don't need).

Jonason

https://www.boards.ie/discussion/comment/121136808#Comment_121136808

Thanks mate,you are quite professional

1)Now hybrid inverters are quite popular?

2)what's your preference for batteries?High/Low voltage,the bigger capacity the better?

3)Software is indeed important

4)You mean 5kw is a nesessity to export to the grid?

5)I believe 0.5C is the most usual case in the market now

I think for all the brands in the market now,they maintain almost a same level when it comes to the hardware,how do you think?

Jonason

https://www.boards.ie/discussion/comment/121136845#Comment_121136845

10)Is the access to historical data that important?You mean configuration right?More convenient to debug?

11)Which brand cna do that automatically?

12)You mean blackstart function?

Jonason

https://www.boards.ie/discussion/comment/121138360#Comment_121138360

Thanks mate.

You mean on-grid is more cost effective than self-consumption?

curioustony

https://www.boards.ie/discussion/comment/121162042#Comment_121162042

A lot of this comes down to setting your goals. Are you trying to limit your impact on the environment; are you trying to go off grid; are you trying to minimise your electricity bill; are you prepared to adapt you lifestyle; is ROI your main driver; are you preparing for an EV or hear pump;...

I went with solar PV based on a back of the developer calculation and a recommendation from a friend. I had no hard facts about how or when I used electricity. No Smart meter, no CT clamps just a very expensive 24hr 2 monthly bill. I saved about 50% in year one. Then I had data. Then I had Smart meter. Then I had options. Now my savings are closer to 80%. I have not adapted my lifestyle at all. (Maybe more importantly I have not asked herself to adapt :-)). I am happy. With government handouts, I have not paid (net) for electricity in over 18 months.

For me getting historical data for both usage and generation has been essential to optimising the system.

When I do eventually go for an EV, I know where to put additional panels. This is based on historical per string data that is sadly for me not easily accessible, and getting harder in Oct. :-(. This is a relative statement not to be tasked as difficult, just a PITA.

So not configuration, just data. The best thing ESBN

https://www.esbnetworks.ie/

have done in a very long time is make Smart meter data available without a Smart plan. Very valuable if you don't yet have an solar PV.

Most, but not all Inverters will have the ability to charge/discharge to grid. Be sure to check it out if it's important to you. A more important aspect is how? Do you need to climb unit an attic space and push buttons? Do you need to use an app? Is there an interface for automation? There is a very healthy thread/community here on automation:

https://www.boards.ie/discussion/2058224611/solar-pv-monitoring-automation-thread

My inverter warranty is void if I participate in a VPP, but I can quite happily load (at a cheap night rate) export solar during the day, and if there is anything left in the battery dump back to the grid before loading again. The last bit requires automation so I don't do that yet... My time is spent on my free android app. It covers a lot of this without telling you what to do.

https://play.google.com/store/apps/details?id=com.tfcode.comparetout

The last one depends again on your goals and setup. If you are going off grid you need the inverter to start when the sun comes up (no grid). If you want power backup in case of storm outage that lasts a couple of days then you need to chat with your installer as there are a lot of regulations in this area. It can be done but may not be ideal in terms of inverter and panel location.