Inheriting a Off Grid Cabin Solar Setup. What would you change?

[Ckole]

Hello,

We are purchasing a property that has over 6000 watts of solar and a dedicated insulated shed for everything. It is an older system that includes a large 1000ah 24 volt Forklift battery. I am reading through all of the manuals. Everything works but it is an older setup. Shed has a exhaust fan but no heat or AC. If anyone has a similar setup I would love to hear your experiences with it.

My first consideration would be to swap out the monster lead acid battery for lithium. I believe 600 ah worth would be plenty for what we are using. 400 ah might even be fine and we would probably start with that. I can't decide if it makes sense to buy some 24 volt 200ah LifePo4 batteries or go with the rack mounted stuff. What are the pros and cons? Then replace other parts as needed when/if they fail.

Here are some photos:
3 solar controllers - each handles 10 - 230 watt panels than can be switched to charge lithium batteries
2 inverters but I believe only one is in use on the building. With the other as a backup
Building has a breaker box and has been wired for power with outlets and some basic lighting.

We plan on installing a 110 v solar mini-split but may have that use its own set of new panels.

This was professionally installed years ago. I have the company information if I ever need to reach out to them.

Any advice is appreciated! Thanks!

 

[OffGridInTheCity]

More clarification on you're thoughts about use-pattern/power-requirements/expansion/monitoring-requirements etc would help.

Assuming no big plans....
I love the Midnite Classics - I run 4 for my 15kw array, the oldest is over 7yrs and works just like the newer ones, all A-OK. They have produced over 100,000kwh of PV to date.

Don't have opinion on Xantrax etc....

Would look at replacing the battery! but then I'm a lithium enthusiast

If the system works then just use it? Old doesn't mean 'bad'!

Nice looking install with troughs and conduit etc - depending on what you plan, try preserve this level of install as you consider options.

 

[Bluedog225]

I’d just run it.

Make a plan before buying anything.

Consider 48 volt.

See if the fans need cleaning.

 

[Koyaanisqatsi]

Hello,

We are purchasing a property that has over 6000 watts of solar and a dedicated insulated shed for everything. It is an older system that includes a large 1000ah 24 volt Forklift battery. I am reading through all of the manuals. Everything works but it is an older setup. Shed has a exhaust fan but no heat or AC.

My first consideration would be to swap out the monster lead acid battery for lithium. I believe 600 ah worth would be plenty for what we are using. 400 ah might even be fine and we would probably start with that. I can't decide if it makes sense to buy some 24 volt 200ah LifePo4 batteries or go with the rack mounted stuff. What are the pros and cons? Then replace other parts as needed when/if they fail.

Yes, definitely go with LiFePo4. Check your equipment to see if any of it can be configured to work with 48V. I expect the Midnight Solar gear might be able to. But probably not the Xantrex/Trace stuff. Nothing wrong with 24V, esp since you already have it that way. Also nothing wrong with any of the equipment you have unless you are experiencing some kind of issue with it. I would say don't replace anything that is working other than the batteries.

Here are some photos:
3 solar controllers - each handles 10 - 230 watt panels than can be switched to charge lithium batteries
2 inverters but I believe only one is in use on the building. With the other as a backup

Those are each 120V inverters, probably one for each side of the typical 120/240V split-phase service in the US. If they are working, keep them. Since you have Midnight Solar charge controllers, it might be fun to replace the Trace/Xantrex units with a single Midnight Solar Rosie inverter. One Rosie would replace both of those Xantrex units, and hardly break a sweat doing it.

Building has a breaker box and has been wired for power with outlets and some basic lighting.

We plan on installing a 110 v solar mini-split but may have that use its own set of new panels.

Get one, but integrate it and its panels with the existing power system, if possible. IMO, it's waste to do those direct to panels, because you need the cooling at a different time of day than when the sun is up.

This was professionally installed years ago. I have the company information if I ever need to reach out to them.

Any advice is appreciated! Thanks!

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This is a really nice system form years past. I don't think you need to do much to it, if anything. Those old inverters are like battle tanks and can take a lot of abuse. Newer stuff is flashy and will gain you some slight performance and monitoring benefits, and maybe some size and weight benefits. But it might not be worth the cost for the gains to replace any of it.

Except the battery. Get that nasty old thing out of there!! (And good luck moving that brick of lead.)

You can get rack-mounted LiFePo4 batteries at 24V in increments of 200Ah from a few manufacturers now. Here is EG4 at Current Connected: https://www.currentconnected.com/pr...tery-voltage[]=24-volts-dc&filteraction=apply. Three of those in a small rack should fit in that same space pretty well.

 

[Q-Dog]

The best thing you can do is just live with that system for a while and see what it does well and what could be better. Make a plan AFTER you figure this out.

 

[dopeassjackson]

Make sure your current CC and inverter is compatible with lithium before changing to lithium.

Is there something wrong with the battery? That's prob 450+lbs of battery you will need to remove.

 

[Ckole]

More clarification on you're thoughts about use-pattern/power-requirements/expansion/monitoring-requirements etc would help.

Assuming no big plans....
I love the Midnite Classics - I run 4 for my 15kw array, the oldest is over 7yrs and works just like the newer ones, all A-OK. They have produced over 100,000kwh of PV to date.

Don't have opinion on Xantrax etc....

Would look at replacing the battery! but then I'm a lithium enthusiast

If the system works then just use it? Old doesn't mean 'bad'!

Nice looking install with troughs and conduit etc - depending on what you plan, try preserve this level of install as you consider options.

100% agree on old doesn't mean bad. I am just trying to gain knowledge on the setup and possible tweaks. IF we connect a minisplit to this setup it would be the largest power draw. Otherwise everything to date is pretty simple. Low power LED lights in a few places, 12 volt water pump, small draw from pellet stove, small fridge.

 

[Mattb4]

In last image it has hydro listed on the panel. Do you have a hydro power setup also for charging? Pretty nifty if so. Other than the battery (it looks like it was maintained) I would not alter things. If you find you need more capacity build alongside this setup by perhaps adding another array, an AIO, LifePO4 battery and output to a panel for your new heavy loads such as the proposed mini split.

 

[Ckole]

Except the battery. Get that nasty old thing out of there!! (And good luck moving that brick of lead.)

You can get rack-mounted LiFePo4 batteries at 24V in increments of 200Ah from a few manufacturers now. Here is EG4 at Current Connected: https://www.currentconnected.com/product-category/btry/?battery-voltage[]=24-volts-dc&filteraction=apply. Three of those in a small rack should fit in that same space pretty well.

Thank you for all of the great comments. The current owner said the company that installed the battery might be interested in buying it back. I will reach out to them once we close on the deal and actually own everything. I like the EG4 stuff. That is the same brand for the Mini Split. Our main heat source is a pellet stove but the Mini Split could serve as a backup.

 

[Ckole]

Make sure your current CC and inverter is compatible with lithium before changing to lithium.

Is there something wrong with the battery? That's prob 450+lbs of battery you will need to remove.

Other than age and maintenance I don't think so. My concern is lack of visits to the property might mean we would damage the battery. Not sure how often it needs water added. I believe it is at least 4 years old. Possibly as much as 6 years old.

 

[Ckole]

In last image it has hydro listed on the panel. Do you have a hydro power setup also for charging? Pretty nifty if so. Other than the battery (it looks like it was maintained) I would not alter things. If you find you need more capacity build alongside this setup by perhaps adding another array, an AIO, LifePO4 battery and output to a panel for your new heavy loads such as the proposed mini split.

No Hyrdo. There is connection for a generator but I don't own one. I don't want to own one and won't use it. The location of the property is generally pretty windy. Maybe one day add a wind generator. BUT unless we use the place for weeks at a time I don't think that will be necessary. More of a long weekend a few weeks a year place.

 

[OzSolar]

Other than age and maintenance I don't think so. My concern is lack of visits to the property might mean we would damage the battery. Not sure how often it needs water added. I believe it is at least 4 years old. Possibly as much as 6 years old.

That's a 10 year or better battery. Zero chance the original company is interesting in buying it back.

 

[Mattb4]

No Hyrdo. There is connection for a generator but I don't own one. I don't want to own one and won't use it. The location of the property is generally pretty windy. Maybe one day add a wind generator. BUT unless we use the place for weeks at a time I don't think that will be necessary. More of a long weekend a few weeks a year place.

In that case I would avoid changing any of it at all so long as it works.

 

[Q-Dog]

Thank you for all of the great comments. The current owner said the company that installed the battery might be interested in buying it back. I will reach out to them once we close on the deal and actually own everything. I like the EG4 stuff. That is the same brand for the Mini Split. Our main heat source is a pellet stove but the Mini Split could serve as a backup.

There isn't anything in there I would replace with EG4.

 

[Ckole]

That's a 10 year or better battery. Zero chance the original company is interesting in buying it back.

I think it was for the value of the lead. Not sure.

 

[Ckole]

Well, I reached out to the original installer. The inverters are no longer supported and can’t handle lithium batteries. So once the beast of a battery dies I will look at replacing things.

 

[Ckole]

There isn't anything in there I would replace with EG4.

I am open to recommendations on other brands. Simplicity would be key. Probably just have one inverter and new batteries to start. Hopefully the current setup lasts for at least 6 months and we can determine what our power needs will be.

Again appreciate all of the timely and great info so far.

 

[sunshine_eggo]

I’d just run it.

Make a plan before buying anything.

Consider 48 volt.

See if the fans need cleaning.

SAME!

The best thing you can do is just live with that system for a while and see what it does well and what could be better. Make a plan AFTER you figure this out.

SAME!

In that case I would avoid changing any of it at all so long as it works.

SAME!

There isn't anything in there I would replace with EG4.

SAME!

---

Chiming in...

If it ain't broke, don't fix it.

Quality hardware EVERYWHERE.

The only ? is the battery, and you have to maintain FLA pretty diligently, or you murder it. We can educate.

The battery is worth the same now as at end of life, so run it till it dies and then simply sell for $0.20/lb and replace with 24V LFP. Replace NOTHING else unless the system isn't meeting your needs.

Those inverters (previously Trace brand) are still the best in the world.

 

[50ShadesOfDirt]

You would still want to run thru the calculations, to see what the current house loads are, plus what you new items you want to add to the house loads. I'd think things have changed load-wise since the system was first installed ...

Because the battery is FLA, and because you are finding that other components (your inverters) don't play well with LiFePO4 batteries (the good stuff), it seems that you'd be better off selling the old stuff (inverters, mppt's, and FLA) to folks who could use those components in their older systems. You'd want to go with newer (48v) everything, and you'll get to keep the solar panels (6kw) worth, after factoring them into the new design. Any money you get will go to the new system.

Before you sell off the (working) old stuff, you'll get the new stuff in, installed, and have an electrician cutover date ... after which, all the old stuff is now ready to yank out and sell off.

So, call up CurrentConnected, discuss all of this with them, and buy your 48v system (new AIO inverters, new LiFePO4 batteries, and anything else needed) from them. These will be sized from your new set of calcs, and hopefully, the solar panels won't need to change much (wiring). You'll (your loads will) be much happier on all new technology, and you can build further on this solution (add a fuel-generator backup, for example). Plus, there is a possibility of a tax credit for the new stuff.

With the old stuff sold off, you'll apply that to the cost of the new system, on top of the tax credit.

Hope this helps ...

 

[Brucey]

I am open to recommendations on other brands. Simplicity would be key. Probably just have one inverter and new batteries to start. Hopefully the current setup lasts for at least 6 months and we can determine what our power needs will be.

Again appreciate all of the timely and great info so far.

As Koyaanisqatsi suggested a Midnite Rosie would be a nice replacement:

MidNite Solar MNROSIE7048M Mobile Inverter/Charger 7000W

Shop now for MidNite Solar MNROSIE7048M Rosie Mobile Inverter/Charger 7000W 48VDC.

www.stellavolta.com

You'll need an mngp2 control panel to program it.

 

[Brucey]

The lead acid doesn't really care about freezing temps but an lfp battery shouldn't be charged at freezing temps or below.

 

[Brucey]

You would still want to run thru the calculations, to see what the current house loads are, plus what you new items you want to add to the house loads. I'd think things have changed load-wise since the system was first installed ...

Because the battery is FLA, and because you are finding that other components (your inverters) don't play well with LiFePO4 batteries (the good stuff), it seems that you'd be better off selling the old stuff (inverters, mppt's, and FLA) to folks who could use those components in their older systems. You'd want to go with newer (48v) everything, and you'll get to keep the solar panels (6kw) worth, after factoring them into the new design. Any money you get will go to the new system.

Before you sell off the (working) old stuff, you'll get the new stuff in, installed, and have an electrician cutover date ... after which, all the old stuff is now ready to yank out and sell off.

So, call up CurrentConnected, discuss all of this with them, and buy your 48v system (new AIO inverters, new LiFePO4 batteries, and anything else needed) from them. These will be sized from your new set of calcs, and hopefully, the solar panels won't need to change much (wiring). You'll (your loads will) be much happier on all new technology, and you can build further on this solution (add a fuel-generator backup, for example). Plus, there is a possibility of a tax credit for the new stuff.

With the old stuff sold off, you'll apply that to the cost of the new system, on top of the tax credit.

Hope this helps ...

The Midnite Classic controllers can handle LFP, no reason to throw them out, already set with spds per string and combiner boxes etc.

 

[Koyaanisqatsi]

You have a top quality installation there, even though it might be old. I think the summary of all this is keep it going as is, until you identify issues with a component or system capacity capacity. Then plan out the changes. But everything in that system is solid until further notice.

 

[Brucey]

Thank you for all of the great comments. The current owner said the company that installed the battery might be interested in buying it back. I will reach out to them once we close on the deal and actually own everything. I like the EG4 stuff. That is the same brand for the Mini Split. Our main heat source is a pellet stove but the Mini Split could serve as a backup.

Eg4 is designed specifically to achieve low price points. Long term durability is not a design factor. You are quite likely to be disappointed versus the rock solid tier 1 equipment you currently have .

 

[sunshine_eggo]

Well, I reached out to the original installer. The inverters are no longer supported and can’t handle lithium batteries. So once the beast of a battery dies I will look at replacing things.

Bullshit. They can be made to work with lithium fine.

In 99.9% of cases, if it works with lead acid, it works with LFP. Period. LFP operating voltage range is nearly identical to FLA. There are some additional considerations, like you'll need to buy LFP batteries that have their own low temp charge protection, and disconnect all the temp sensors to your chargers (you don't need temp compensation on LFP), but that's about it.

Back in the day, Volvo had a crazy reputation for reliability. Let's say that's still true... they're crazy reliable.

No one in their right mind would replace a Volvo with a Yugo. Please don't replace your Volvo with a Yugo.