most bang for buck -EV Charging from solar

[Ozark Tinkering]

oh i missed it was a lightning, i thought we were talking about Ys lol

Hopefully OP will see that too.

 

[Ozark Tinkering]

I always beat the ratings for miles per watt. I'm always in the right hand lane.

 

[karkit]

what the hell are you doing with it?
Ive done 3.5m/kw in my bolt for 30k miles and my driving is 95% freeway speeds.
and it has the CD of a tractor, teslas should be higher number more efficent at speed.

lol!!
I went 16.8 miles and topped it off with 3.9kwh. this was not driving it to work. This was 55mph short trip to the store. I run 77mph for 30 miles when I commute to work. I will have to check and see what that turns out to be.

 

[Ozark Tinkering]

lol!!
I went 16.8 miles and topped it off with 3.9kwh. this was not driving it to work. This was 55mph short trip to the store. I run 77mph for 30 miles when I commute to work. I will have to check and see what that turns out to be.

.

 

[karkit]

I'm powering my level 2 charger with the 10kW SunGold AIO that Will recently did the review on. It's been flawless since powering up on Sept 8th.

This is the one I am talking about!! PLease tell me about your system. I know I would need more panels too. I want to run my EG4 mini, 24k BTU, at night as well. What I do not wish to spend a ton of money and never recoup the expense. I am looking to retire in maybe 5 yrs.
Thanks

 

[Ozark Tinkering]

This is the one I am talking about!! PLease tell me about your system. I know I would need more panels too. I want to run my EG4 mini, 24k BTU, at night as well. What I do not wish to spend a ton of money and never recoup the expense. I am looking to retire in maybe 5 yrs.
Thanks

Sure. I'm powering during the day with an 11kW array consisting of 28 bifacial panels laying on a hillside facing south. Right now I'm powering half of my house and all of my shop, including a 12k mini split, 2 freezers and a frig/freezer with it. At night it's supplied by 3 Eco-Worthy 100ah server rack batteries (15kWh). My shop has 3kW of old florescent tube lighting. I can run all of my lights at the same time and start my compressor while doing it. The other half of my house is still grid connected because I also have a 5kW rooftop Enphase system grid-tied that is offsetting my usage there. After energizing the SunGold inverter on Sept. 8th, it did its thing for 17 days of the billing cycle. That brought my utility bill down to $26 for the month. I'm over paneled for my needs at this point.
Didn't I see you're in Al? You probably won't be using your mini split for heating nearly as much as you will for cooling. They're really efficient when cooling, especially at night.

 

[karkit]

Sure. I'm powering during the day with an 11kW array consisting of 28 bifacial panels laying on a hillside facing south. Right now I'm powering half of my house and all of my shop, including a 12k mini split, 2 freezers and a frig/freezer with it. At night it's supplied by 3 Eco-Worthy 100ah server rack batteries (15kWh). My shop has 3kW of old florescent tube lighting. I can run all of my lights at the same time and start my compressor while doing it. The other half of my house is still grid connected because I also have a 5kW rooftop Enphase system grid-tied that is offsetting my usage there. After energizing the SunGold inverter on Sept. 8th, it did its thing for 17 days of the billing cycle. That brought my utility bill down to $26 for the month. I'm over paneled for my needs at this point.
Didn't I see you're in Al? You probably won't be using your mini split for heating nearly as much as you will for cooling. They're really efficient when cooling, especially at night.

Thanks for sharing. Yes, I am in Alabama. We only have 5 panels running our 24k BTU mini. It is a ground mount. We have 10 more not installed. I think we may look into this inverter. It is less expensive than everything that I have been looking at.
We are in a big pasture, so we have plenty of room and no shade, lol. I want to charge the Model Y LR RWD as much as I can and run the 24k BTU unit at night, if possible. It is so efficient. We are empty-nesting, so we are not using much of our house, and the 5-ton unit is a power hog!!!!
Thanks again!

 

[Ozark Tinkering]

Thanks for sharing. Yes, I am in Alabama. We only have 5 panels running our 24k BTU mini. It is a ground mount. We have 10 more not installed. I think we may look into this inverter. It is less expensive than everything that I have been looking at.
We are in a big pasture, so we have plenty of room and no shade, lol. I want to charge the Model Y LR RWD as much as I can and run the 24k BTU unit at night, if possible. It is so efficient. We are empty-nesting, so we are not using much of our house, and the 5-ton unit is a power hog!!!!
Thanks again!

I bought it on Amazon and took the 2 year warranty option because I was a skeptic, and still kept it in the $2k range after tax. I probably wasted my $200 on the Amazon warranty, but that's okay.

 

[42OhmsPA]

I'm powering my level 2 charger with the 10kW SunGold AIO that Will recently did the review on. It's been flawless since powering up on Sept 8th.

I've been using the OEM version (in parallel) to run my entire house, a single unit handled 32A charging no problem. I do have ~14.5kW PV and ~55kWh LiFePO4 to support it.

 

[Ozark Tinkering]

Yes, I am in Alabama. We only have 5 panels running our 24k BTU mini. It is a ground mount. We have 10 more not installed.

If you already have 5-400 watt panels connected, you are most certainly not using them to their potential, without having batteries. There's no way a 24kbtu mini-split will require the 10 kWhs a day for cooling, that a 2,000 watt array is capable of producing on a sunny day. You could be stuffing the extra into a battery for later use on a cloudy day. Keep in mind though that the SunGold inverter like all other inverters, has needs of its own to the tune of 100 watts per hour. It takes power to make power.

 

[Ozark Tinkering]

I've been using the OEM version (in parallel) to run my entire house, a single unit handled 32A charging no problem. I do have ~14.5kW PV and ~55kWh LiFePO4 to support it.

The only reason I'm not running the whole house with mine right now, is because I originally fed my shop from a sub panel at the far side of the house from my utility service, and if I open the rest of the house to off-grid power through manual switching, I'll lose my Enphase system when I do. I still plan 3 more batteries for this year, wifey wants a lot more next year. It's a great hobby when yer wife likes it too! I got that goin for me. Phase 2 will be to install a new outdoor branch circuit panel alongside my main panel with an auto transfer switch. I plan to leave my LED yard light on the utility side (that'll tell me if the utility power went out at night ), along with my rooftop Enphase system. Then I'll make my SunGold the primary supply. I won't have those changes complete until after winter, but my plan is to build huge credits all year long through my net metering agreement, to cover me in those cold winter months when my electric bill soars to as high as $180. I'm ending that once and for all.

 

[42OhmsPA]

If I were starting over knowing what I know now I would have started with a small grid tied system to take advantage of the 1:1 net metering in PA...

 

[Ozark Tinkering]

If I were starting over knowing what I know now I would have started with a small grid tied system to take advantage of the 1:1 net metering in PA...

I'm in Arkansas and last year they rewrote the rules for net metering, so it's no longer 1 for 1 for new accounts. I'm grandfathered in until 2040 on a 20 year agreement. By then if I'm still around I doubt I'll care about much, except when the oatmeal is served because ice cream comes next. My son is building a house in Missouri and I understand they still have 1 to 1 net metering for new accounts. I think anyone who can, should.

 

[karkit]

I'm in Arkansas and last year they rewrote the rules for net metering, so it's no longer 1 for 1 for new accounts. I'm grandfathered in until 2040 on a 20 year agreement. By then if I'm still around I doubt I'll care about much, except when the oatmeal is served because ice cream comes next. My son is building a house in Missouri and I understand they still have 1 to 1 net metering for new accounts. I think anyone who can, should.

We do not have net metering available!
Thank you for sharing. What batteries do you have?

 

[Ozark Tinkering]

We do not have net metering available!
Thank you for sharing. What batteries do you have?

I started with 3 Eco-Worthy 51.2 Volt 100 AH server rack batteries and will add 3 more before the tax credit runs out on Dec. 31st.

 

[karkit]

I'll bite. Please be patient and keep an open mind. Most new folks need to provide more information.


1. I don't own a Tesla so I don't know how fast a level 2 charger goes for a Tesla. Using an optimistic 48A at 240v = 11.5kw for a 50A circuit.

2. Your PV array is 6kw (15x400) so using an very ideal 5 hours of full sun, total daily PV would be 30kw.

3. A useful average efficiency is 72% from lifepo4 batttery from your battery bank to what gets to your Tesla battery. In more techy talk, DC to AC and AC back to DC. Theoretically, if you had a fully charged 50 kwh battery bank, then 36 kwh could make it to your Tesla battery. Charging time would be about 3 hours assume a 11.5 kw max charge rate for a level 2 charger running on a 60a breaker.

Here is some more the math.

Your inverter will operate at 85% efficiency to convert the DC battery to AC power.
Your charging circuit in your Tesla will operate at 85% to convert that AC power from the 50a outlet to DC for the Tesla battery.
85% x 85% = 72%

Feel free to tweak the numbers. Some may say it is 88% and 90%. Efficiency varies with hardware, temperature, battery state of charge, etc, etc. I use 85% as a conservative number and its easier to remember.


4. Prices for batteries range from $75/kwh (DIY) to $200/kwh (pre-built) or more. For a couple of pre-built battteries that make up about 50kwh, then it will cost you $10,000

5. PIck your favorite inverter ecosystem. It really doesn't matter. $6,000 is a good middle of the road budget for the actdual unit(s) only..

6. Hopefully, it is becoming more clear that your limitations are your solar array size (incoming energy) and your battery bank size (how much you can store).


7. Simple math. Spend $40 - 50,000 for a solar system to charge your EV OR just spend $200 a month to charge from the grid and stop at any time if plans / preferences change.

The quick 2 second decision would likely be spend $200 to charge the EV for a couple of months and decide on a long term plan.

There are many benefits and use cases to spending say $50k on a solar system with battery storage. If you work for your money (e.g. are not rich), then try to find more uses..


Hope that helps.

Thanks for the information depth answer! Very helpful.