want to start my first DIY solar to power 2 mini splits and an EV charger

[Smasher3545]

Hi everyone!

I've been watching all the solar related videos I can but the maths and planning is still a little confusing. So thought I'd post this to get some help.
What I'm planning on doing is building a DIY solar system to power 2 mini splits and an EV charger.
I live in a mobile home and can't have solar on the roof, so I had a porch roof extension built specifically to install solar panels on, but no installer will do it even on this.
I live in Texas were we've lost power last 2 Februaries so I wanted to do this DIY so I don't freeze during power outages.
I have 2 mini splits and a circuit to plug in my ev charger for my 2020 Nissan Leaf currently in my house's breaker panel
I was thinking of moving them to a battery pack that is charged by solar. My thoughts were to get a shed in the back yard to put the batteries and circuitry in, solar panels on the front porch roof extension, run the wiring to the back yard and the ground wire to the mobile homes breaker panel ground.

here's the details of the items:

Single zone mini split:

• Pioneer Low-Ambient 12,000 BTU 1 Ton 20 SEER Ductless Mini Split Wall Mounted Inverter Air Conditioner with Heat Pump 110/120V
• Voltage of 110V - 120V, 60Hz, 1Ph
• 10 Amp circuit
• 12 AWG
• 1070 watts
• The unit uses soft start technology, and ramps up to rated power depending on indoor setting. My unit starts at 300 watts and ramps up slowly to about 750-790 depending on temperature. When the first apply power, it will ramp up to the maximum, then reduce to rated. (max 1000 watts).
• SEER = 20

3 Zone mini split:

• Pioneer Multi 27000 BTU 3 Ton 22 SEER Triple (3) Zone Wall Mount Air Conditioner Heat Pump Ductless Mini Split, 208/230 V
• Voltage: 208 - 230-Volt, 60 hertz, 1 phase (standard household 2 line power, l1-l2-g)
• 30 Amp circuit
• Depending on the demands, this unit draws between 670 to 3210 watts in operation
• 980 watts per head unit, so with a triple zone, it would be about 3kW at most, when running at max capacity.
• 10/2 AWG wire.
• SEER = 22

Car Charger:

• 50 Amp circuit breaker currently installed in house breaker panel
• 220v
• 2020 Nissan Leaf
• 6.6 kW onboard charger

So what size battery bank would I need and what size solar system would I need to keep the batteries charged? Any other advise?

thank you!

 

[MisterSandals]

what size solar system would I need to keep the batteries charged?

How many watt hours each day will your 3 items consume each day? Divide this number by 5 solar hours to get your array size.

If you run your split minis and charge your car while the sun is shining you won't need a lot of battery. How much of your daily watt hour usage will be consumed outside your 5 solar hours? This is how much battery your system will need.

 

[SamDeleted]

Car Charger:

• 50 Amp circuit breaker currently installed in house breaker panel
• 220v
• 2020 Nissan Leaf
• 6.6 kW onboard charger

Your nissan leaf can be charged at pretty much any rate you choose BELOW that 6.6kw

usual charge ours at 2kw , and only in daylight hours , letting the panels production cover charging the leaf so it doesn't ever dip into the batteries

We use an adjustable type 2 wall outlet charger , we call them 'granny' chargers in the UK . you'll have to see what's available in the states obviously

https://www.amazon.co.uk/FNRIDS-Charger-Portable-Electric-Adjustable-5M/dp/B0BSBXL9J1/ref=mp_s_a_1_4?keywords=ev+charger+type+2&qid=1685262689&sr=8-4

 

[Smasher3545]

of the 3 mini splits indoor units, 2 of them run 24/7, one runs during the day when I'm asleep [I work nights], and the last one runs almost 24/7 but I shut it off now and then. For my charger I ran a wire from the breaker panel to my car port and connected that end to an RV outlet 50-Amp RV Power Outlet that I plugged the level 2 charger that came with the Leaf.

 

[good4politics]

Hi everyone!

I've been watching all the solar related videos I can but the maths and planning is still a little confusing. So thought I'd post this to get some help.
What I'm planning on doing is building a DIY solar system to power 2 mini splits and an EV charger.
I live in a mobile home and can't have solar on the roof, so I had a porch roof extension built specifically to install solar panels on, but no installer will do it even on this.
I live in Texas were we've lost power last 2 Februaries so I wanted to do this DIY so I don't freeze during power outages.
I have 2 mini splits and a circuit to plug in my ev charger for my 2020 Nissan Leaf currently in my house's breaker panel
I was thinking of moving them to a battery pack that is charged by solar. My thoughts were to get a shed in the back yard to put the batteries and circuitry in, solar panels on the front porch roof extension, run the wiring to the back yard and the ground wire to the mobile homes breaker panel ground.

here's the details of the items:

Single zone mini split:

• Pioneer Low-Ambient 12,000 BTU 1 Ton 20 SEER Ductless Mini Split Wall Mounted Inverter Air Conditioner with Heat Pump 110/120V
• Voltage of 110V - 120V, 60Hz, 1Ph
• 10 Amp circuit
• 12 AWG
• 1070 watts
• The unit uses soft start technology, and ramps up to rated power depending on indoor setting. My unit starts at 300 watts and ramps up slowly to about 750-790 depending on temperature. When the first apply power, it will ramp up to the maximum, then reduce to rated. (max 1000 watts).
• SEER = 20

3 Zone mini split:

• Pioneer Multi 27000 BTU 3 Ton 22 SEER Triple (3) Zone Wall Mount Air Conditioner Heat Pump Ductless Mini Split, 208/230 V
• Voltage: 208 - 230-Volt, 60 hertz, 1 phase (standard household 2 line power, l1-l2-g)
• 30 Amp circuit
• Depending on the demands, this unit draws between 670 to 3210 watts in operation
• 980 watts per head unit, so with a triple zone, it would be about 3kW at most, when running at max capacity.
• 10/2 AWG wire.
• SEER = 22

Car Charger:

• 50 Amp circuit breaker currently installed in house breaker panel
• 220v
• 2020 Nissan Leaf
• 6.6 kW onboard charger

So what size battery bank would I need and what size solar system would I need to keep the batteries charged? Any other advise?

thank you!

It's all just math. You will need a LOT of battery. Stick with a pure 48v system. Figure out where you are going to store all these batteries. You'll need at least a 4 foot wide heavy steel work shelving unit that can handle the weight of all the batteries. Alternatively, you can use PC server racks with batteries designed to fit in them. It makes a much cleaner/smaller install. The panels are the easy part. Batteries, heavy guage wire, room for the batteries and inverter(s) is the hard part.

I am using 4 9000 BTU units on a 2400 sqft house in Arizona. Each unit is 21.5 SEER, max 700w. All are 120v. Advantages: No need for 240v wiring or inverters. No one failure takes down other units. The house is tolerable with only 2 units. 4 will allow most of them in "ECO mode" which only works at 75 degrees or above but each unit only consumes 300w. I cannot talk about heating as it's a non-issue in Phoenix. I have not used them over winter yet but looking forward to it.

In my case, each unit will run off it's own dedicated Victron Phoenix 48/1200 GFCI inverter. Currently using a Chinese WZRelb 3000w PSW inverter and it won't run 2 units without overheating due to cheap insufficient fans. I think it would do very well indoors or with more cooling.

Your solar "shack" (the area where you put the batteries/wires should be air conditioned. LifePo4 batteries get angry an swell up like a blowfish if overheated.

In summary, I recommend single head units unless you can't have that many around your dwelling. There seems to be no performance penalty over multi-head units. They are also a lot cheaper to replace if you blow one up. Your car charger will be the issue as it needs 220v.

Maybe you should have made that roof extension directly out of solar panels. A good 400+ watt panel is around 80 inches long and 40 inches wide. 3 side by side are 10 feet wide and 6 feet, 8 inches deep. 30 foot mobile home = 9x400 = 3600w without being obvious or an eyesore. Not sure you have the solar panel space for the type of wattage you are planning. The 9000 BTU blows 62 degree air at max settings in 111 degree weather. Whisper quiet too. I need to put a kill-a-watt meter on it to see if the specs are true. My Medea U-shape window unit is 12000 BTU, essentially an inverter mini-split stuffed into a window unit. It tops out at 1300w in hot weather on the Kill-a-watt. Not as cool either.

 

[DIYrich]

How many feet of wire are you looking at to the shed? More than a few feet may be expensive.

Do you need time shifting of power to charge the car? Batteries to store energy to transfer to the car is expensive. It also adds a few panels just for the car. I like the Aptera if they ever start producing it. Let the car charge itself.

 

[good4politics]

Performed a kill-a-watt test on newly installed 9000 BTU Pioneer 21.5 SEER units. Cooling a 13x20 room down to 62 degrees in 110 degree weather pulled over 1400 watts. Twice the specification max claim of 666 watts. However, setting the units to "ECO" at 75 degrees reduced power consumption to less than 450w cooling the same 260 sqft room.

 

[Smasher3545]

got busy with life [and 3 surgeries] and forgot to check back in on the forum ?‍ok sounds like charging the car through solar/batteries would be too expensive and money is a little tighter now, so maybe I should start with just powering the mini-splits. And with money being a little tighter I may need to buy things a bit at a time, so maybe start with just enough to power the single zone mini split in the bedroom as that should be the least expensive way to start. And that way during the next power outage [every February in Texas for last 2 years] I'll at least be able to sleep without freezing. That should also cut my electric bill down, help me save money for the next phase of the project.

per @good4politics the shack needs to be air conditioned so that is another expense to take into consideration. A window unit type thing that's also powered by the solar panels / batteries?

@DIYrich There's about 55 feet between the 2 units with my back porch in between. Perhaps I could put the batteries on the back porch and build an enclosure with the air conditioner unit attached to keep the batteries cool?

Also, I was thinking about the grounding for the solar panels. I've seen videos where people have ran the grounding wire into the ground but since I live in a mobile home park I'm not sure the park owner would be happy with my doing that and there nice hard rock that's not very far below the top soil so not sure I'd be able to do it anyway. So what I was thinking of doing was run the grounding wire under the house and up the conduit that the existing electric wires run through to the breaker panel and then connect the grounding wire to the ground inside the breaker panel. Would this be ok to do?

 

[Smasher3545]

I just had a thought [ouch! lol] maybe it'll be a less expensive way to get started with my solar project, maybe not... Is it possible to charge my EV directly with solar? Here's my current setup:
the 2020 Nissan Leaf I initially mentioned. It has a 40 kw battery
I use the level 2 charger that came with the vehicle
that plugs into a Connecticut Electric 50-Amp RV Power Outlet mounted in the carport
I ran cable from the outlet under the house to a 50 amp breaker in the breaker panel

I work from home and so don't drive a lot so charging a bit each day or every few days should be ok.

I'm wondering if there's a way to have solar panels that go to maybe inverters to get the 240v and then connect those to the Connecticut Electric 50-Amp RV Power Outlet? and maybe add a switch to keep the existing wiring to the breaker panel and manually switch between the 2 so that on very cloudy days I can charge from house electric if needed

 

[Smasher3545]

aaaannnnddd I found this...

which seems close to what I want. Are batteries necessary or can it be done without batteries?

 

[Smasher3545]

pardon the multiple posts, lots of thoughts popping into my brain ? I'm thinking more about money being tight currently while still wanting to get into solar. Seems any kind of battery system is going to be expensive due to need for a shed with a/c etc.
So... now I'm thinking I should start small and build over time. i.e. go with just solar panels to reduce my electric bill, but build it out slowly as money allows. If it's ok to run the ground wire for the panels to the ground in the breaker box like I previously asked, maybe I should start by building out the mounting for the panels [my porch roof extension has a 4 degree tilt and faces around 211 degrees S.
From what I've read ~26 is optimal year round angle for my location.
I haven't seen non-ground mount racking systems that are at angles other than ballast systems [like the Unirac RM10] which would limit me to 1 row of panels due to footprint of roof, weight limits of ballast systems, area needed for the ballast systems, etc. [unless it would be ok to have the north side of the ballast system on top of the house roof] So I'm thinking of getting wood locally and building 2 rows of frames to mount rails on. Then buy solar panels as money allows, along with those Hoymiles micro-inverters that can handle multiple panels with a single micro-inverter.
That way I can build out my system as money allows while slowly reducing my monthly electric bill.