Suggestions for off-grid system

[bladetoyshop]

Good evening folks. I've been following Will on YouTube for a while now, and am finally getting ready to build an off-grid solar system. My basic plan is as follows:

2 MPP Solar LV6048 all in one units connected in parallel for 12KW output
400AH battery bank at least
20 solar panels

I need an affordable option for the battery bank; I would prefer to build my own from individual cells and BMS but would like to know which ones are the best option.

Thanks.

 

[bladetoyshop]

Well, I've done a bit of research now and have decided on the following strategy:

Starting configuration:
1 MPP Solar LV6048 configured as split phase (240 VAC)
16 3.2V 280Ah Lithium Iron Phosphate Cells @51.2 VDC (also called 48 volts)
24 270W 35.5v Solar Cells
1 Batrium Watchmon Core with Cellmate K9 BMS
1 8-2 PV Combiner Box

This starting configuration will give me 6.48kW of Solar input to the LV6048 which will be running the house and garage here. It will also have an 8kW gasoline generator as backup.

I will be adding an identical system next year, in parallel with the existing system. This upgrade should allow me to run a 5HP 240VAC two-stage air compressor completely off the grid; I know the starting configuration will run my smaller 240VAC compressor, as well as a smaller 120VAC one I have.

One planned addition is a home-brew wind turbine backed by a MidNite Solar Classic 200 (or 250; I haven't decided which quite yet) Charge controller and a MidNite Solar DC Clipper. These will help reduce the effects of cloudy days by allowing the battery bank to be charged at any time there is sufficient wind to provide power to the Classic.

 

[bladetoyshop]

Revised my installation plans; I've decided to go with the Growatt SPF 5000 ES and a SolarEdge Midpoint Transformer instead of the MPP Solar LV6048. I'm also going with 24 250 Watt Solar Panels instead of the 270 Watt ones I originally considered. Should have the basics of the system online by Thanksgiving if the parts all come in on time.

 

[houseofancients]

why the switch to the growatt if you dont mind me asking ?

 

[bladetoyshop]

why the switch to the growatt if you dont mind me asking ?

Two main reasons; lower cost and native support in Home Assistant.

 

[houseofancients]

there are a number of hass.io addons that add support to hass.io.
the support can be locally provided by watts247.com

cant agrue lower cost

 

[bladetoyshop]

Yes, I know there are unofficial add-ons for Home Assistant that support the MPP Solar all in one units, but there is an Official Integration for the Growatt brand units I decided to go with.

 

[houseofancients]

Yes, I know there are unofficial add-ons for Home Assistant that support the MPP Solar all in one units, but there is an Official Integration for the Growatt brand units I decided to go with.

you are aware these official plugins arent connecting directly to the inverter, bit to the growatt monitoring website ?
it requires their wifi dongle ( that only connects to their website), and that this website is hosted in china ?

 

[bladetoyshop]

you are aware these official plugins arent connecting directly to the inverter, bit to the growatt monitoring website ?
it requires their wifi dongle ( that only connects to their website), and that this website is hosted in china ?

Yes, I'm aware that the official plugins are cloud based. I also know that there are at least two different servers; one for Asia and one for the US, and there may well also be one for the EU. I'm looking more at ease of integration than having local control, at least for the time being. I have the new Home Assistant Amber hardware on order, but it won't be out until late next year.

 

[bladetoyshop]

Well, I guess it's time for a status update. I fired up the system on February 2nd of 2022. Other than a minor issue with the BMS I ended up getting, the system has been working very well. I will be upgrading it to 10-15 kW of solar power for my house and garage.