Is the EG4 18Kpv the best choice for my new installation? Your thoughts please!

[Gold Country Russ]

If you have NEM-3 authorization, nothing special there, that's what everything is going forward. You could make the system bigger or smaller, or add batteries. Maybe need to apply for a new authorization to make major changes. What inverter is named on the authorization?

If you have NEM-2 authorization and mistyped NEM-3, then Congratulations! It offers a special deal that has gone the way of the dodo. But now what you install must fit within a number of limits regarding PV array size, inverter rating, and no battery (at first) if battery wasn't part of the reservation. In that case, battery can be added later.

The stuff about UL listed ESS I've been hearing - likely no way FLA forklift battery is part of a listed ESS. Getting permit office and utility signoff of a batteryless system could be the way to go. Then hook up a battery when no one is watching. Maybe inverter + lead-acid is still possible with compliance to code, but we've been hearing something otherwise.

95% positive I will buy that 3,000lb 48V battery, it is new (made 2023), it will provide about 560 useable KWH, it has a useable life of 7-10 years, and it will cost me about the same as two EG4 batteries. I don't really care what PG&E thinks. I wanted to use 32 panels (12.8KW), but they limited me to 24 (9.6KW). I actually bought a full pallet of 35 400W bifacial panels and with my heavy-duty water-cooled propane generator and its dedicated 300-gallon tank, I really won't have any need to be grid-tied anymore. Last July (A/C on 24hrs day) we averaged 41KWH per day but even with only 24 panels (@400W) the ground mounted, true south facing, and seasonally adjustable bifacials will perform better than most rooftop installations because we have ideal sun, they will run cooler, and will give a bonus 15% or 11KWH. That should easily meet our needs and recharge the battery to 100% every day even with the A/C. The split-phase generator will run everything if the inverter is down and if necessary, the generator can charge the battery thru the EG4 18Kpv inverter which can charge 48V @200 amps. The more I think about it the less I need PG&E and their grid-tie rules. That said, I will stay grid-tied because it would make our house more valuable when or if we sell it.

 

[Hedges]

Shallow cycles, people say they get 20 years from a forklift battery.
There are automatic watering caps, so you just push a plunger to top off all cells.
Your usage pattern needs to allow full charge and absorption time. Inverter can be set for optimum charge current to keep FLA happy.

"Voltage Range 40–60 VDC" If EG4 18kpv only delivers 60V maximum, I don't think that is sufficient for equalization. Maybe you will need a separate charger powered by generator for that. If battery has individual cell terminals accessible, maybe they can be individually charged to same voltage - not sure if that is better than equalizing which over-chargers some cells, or if equalization charge is needed to knock sulfation off. There are balancers for FLA. I haven't dealt with any other than automotive batteries.

I see EG4 18kpv on the California CEC approved list (also Schneider XW Pro). 18kPV can be commissioned without batteries, maybe easier to get permits and approvals.

Is your reservation with PG&E NEM-3? or NEM-2?

If you add more PV panels, they'll never know so long as export through meter never exceeds what's allowed. With two orientations, peak could be same but more hours of output. That is also good to fully charge battery, and keep it charged later in the day. You'll probably have all loads downstream of the inverter, but if upstream, CT at meter should let inverter limit export.

Generator costs $1.00/kWh, PG&E maybe $0.25 to $0.50 and is more convenient.
If you do use generator, see if you can do "combined heat and power", maybe heat exchanger in cooling system supplying heat to house. Could also make heat exchanger for exhaust.

 

[Zapper77]

heat exchanger in cooling system supplying heat to house. Could also make heat exchanger for exhaust.

The old AirCooled VWs.

 

[Hedges]

Here is what I would use for FLA, generator, in the mountains:

SMA Sunny Island Off-Grid Inverter (SI6048-US-10) | eBay

Find many great new & used options and get the best deals for SMA Sunny Island Off-Grid Inverter (SI6048-US-10) at the best online prices at eBay! Free shipping for many products!

www.ebay.com

2x Sunny Island for $1500 each. Add one more more Sunny Boy; the current -41 model (soon to be replaced with a hybrid?) should qualify for connection to PG&E as grid-tie. If backfeeding the grid through Sunny Island, maximum of 13.4kW GT PV inverter downstream of 2x SI.

People say SI is very good at maintaining FLA. I'm using it with AGM.

 

[Coz]

A few days of overnight kWh is all you need to size a battery bank. I would divide your number by 88% to factor efficiency in

Well, I checked the reading last night at 5pm and had 64272 and this morning at 9am it was 64300. So I multiplied that by 3 and divided that number by 88%. So the kwh usage 64300 - 64272 = 28 x 3 = 84 divided by 88% = 95.45.
So I am not sure where to go next with these figures to be able to calculate how many batteries I need. I plan on using EG4 batteries.
jeff

 

[Zapper77]

Well, I checked the reading last night at 5pm and had 64272 and this morning at 9am it was 64300. So I multiplied that by 3 and divided that number by 88%. So the kwh usage 64300 - 64272 = 28 x 3 = 84 divided by 88% = 95.45.
So I am not sure where to go next with these figures to be able to calculate how many batteries I need. I plan on using EG4 batteries.
jeff

Looks correct. 30 kWh over night seems high for the load that you described above. Was it abnormally hot, excess water heating or just a large house?

 

[Zapper77]

Well, I checked the reading last night at 5pm and had 64272 and this morning at 9am it was 64300. So I multiplied that by 3 and divided that number by 88%. So the kwh usage 64300 - 64272 = 28 x 3 = 84 divided by 88% = 95.45.
So I am not sure where to go next with these figures to be able to calculate how many batteries I need. I plan on using EG4 batteries.
jeff

90 kWh would be 18 EG4 batteries (pushing $30,000). You may want to double check your peak demand requirements.

 

[SignatureSolarJames]

I would not multiply by 3

If you are trying to zero out your bill alll you need is one day reserve. Spend a few hundered on a budget generator to top off the bank for a few hours if you were in a bad period looking for backup. I run on aa 1.5 day bank and only use a genset fully off grid around 40 hours a year.

 

[Coz]

I would not multiply by 3

If you are trying to zero out your bill alll you need is one day reserve. Spend a few hundered on a budget generator to top off the bank for a few hours if you were in a bad period looking for backup. I run on aa 1.5 day bank and only use a genset fully off grid around 40 hours a year.

Just trying to figure out how many eg4 batteries I need to work with the 18k to make it through the night running my well pump, hotwater heater and heat pump.

 

[Coz]

Looks correct. 30 kWh over night seems high for the load that you described above. Was it abnormally hot, excess water heating or just a large house?

well, the 30 kwh of course includes my whole house on the grid. During the day or whenever I run it, all my 110 loads would be run with my other inverter, not the 18k. So it is hard to tell by my meter what just those 240v loads would be.

 

[SignatureSolarJames]

well, the 30 kwh of course includes my whole house on the grid. During the day or whenever I run it, all my 110 loads would be run with my other inverter, not the 18k. So it is hard to tell by my meter what just those 240v loads would be.

A reading at 5pm to 9am gets you the battery kWh per day

 

[Coz]

A reading at 5pm to 9am gets you the battery kWh per day

Sounds good, Well, the 30 kwh would be accurate with the whole house on the grid and includes 110v and 240v loads. But being I am only going to use the 18k for the 240v loads, I would have to somehow separate that from the 30kwh to figure out what that draw would be.
What I am hoping is that (3) eg4 batteries would be good enough to start with for an emergency for part or all of the night just running the well pump, hotwater heater and heat pump. Next year, I would add more batteries.
And to start with this year, I would be having (4) 410w solar panels for a total of 1640 watts going into the 18k and adding 4 - 8 more panels next year.

 

[SignatureSolarJames]

Sounds good, Well, the 30 kwh would be accurate with the whole house on the grid and includes 110v and 240v loads. But being I am only going to use the 18k for the 240v loads, I would have to somehow separate that from the 30kwh to figure out what that draw would be.
What I am hoping is that (3) eg4 batteries would be good enough to start with for an emergency for part or all of the night just running the well pump, hotwater heater and heat pump. Next year, I would add more batteries.
And to start with this year, I would be having (4) 410w solar panels for a total of 1640 watts going into the 18k and adding 4 - 8 more panels next year.

good mentality, I like to think of this like building a PC, either start with way too much ram/HDD or add as you need. our packs and inverters stack for this to be easy enough