New system advise

[maclover1]

Hi,
I am in SW Florida and looking into a new solar system, that would hopefully allow me to get free from the current provider FPL.
Our monthly usage is between 1300 kwh/mo in cooler months and 1800 kwh/mo in the summer (roughly around 55 kwh/day).
After hurricane Ian, we were without power for over 2 weeks, living off of small 2k generator, which prompted us to think about solar.
I was hoping to start with a smaller build and than scale up as necessary. Based on Will's Youtube channel (which brought me here), I really like the EG4 18kpv inverter. which I thought would be a great start for about 13kw system. Also thought of adding 2 EG4 PowerPro batteries and 28 Canadian Solar 400w panels.
I spoke to a couple of local solar company reps, who are telling me that 1. batteries do not make sense as power company has net metering, 2. micro-inverters are so much better (without being able to explain why...) over a single inverter. Both came back with a system design which would cost upwards of $50k and be mounted on three sides of our roof (we have a small house). Granted this is with permits, electrician and permits, however something tells me I should not believe the "solar bros".
That being said SignatureSolar is currently running their BlackFriday sale so all comes up to about $17k with shipping. Is this a good price?

So here are my questions;
- What in reality would a 13kw system do for us on a day to day basis and what about the nighttime usage would the batteries allow us to not have to pull from the grid?
- Would the EG4 18k allow us to be connected to the grid, but at the same time allow for the system to be used during power outage
- Are there any other components that we should consider to be added to the system (additional brakers/ switches, etc.)
- Any thoughts on the EG4 system or the solar panels? Perhaps there would be a different build you would recommend?
- Anyone here from FL that has experience with battery set up? Is it worth it, or should we consider buying a bigger, dirtier, louder and more fuel hungry generator for power outages?

 

[sunshine_eggo]

something tells me I should not believe the "solar bros".

Correct.

So here are my questions;
- What in reality would a 13kw system do for us on a day to day basis and what about the nighttime usage would the batteries allow us to not have to pull from the grid?

55kWh/day.

You can almost certainly count on 5 solar hours / day:

55kWh/5 = 11kW

28 * 400W panels = 11.2kW

So, you are set to meet your average daily consumption with the selected PV

- Would the EG4 18k allow us to be connected to the grid, but at the same time allow for the system to be used during power outage

Yes. It can also be used as a backup, i.e., not actually interacting with grid - simply drawing from it of you run out of PV or battery power.... Think of it as "off grid with grid backup."

- Are there any other components that we should consider to be added to the system (additional brakers/ switches, etc.)

Always. Consult the manuals.

You definitely need more than 10kWh of batteries. Generally speaking, you want battery capacity equal to your daily consumption, so you can survive 24 hours without charging. Recommend 11 batteries based on 55kWh consumption.

EDIT: didn't realize the PowerPro were about 14kWh. You'll need 4, not 11.

- Any thoughts on the EG4 system or the solar panels? Perhaps there would be a different build you would recommend?

Fine.

- Anyone here from FL that has experience with battery set up? Is it worth it, or should we consider buying a bigger, dirtier, louder and more fuel hungry generator for power outages?

Not from FL.

If you want power when grid-down, you can't rely on just grid-tie. Period.

A bigger generator will absolutely, positively be substantially cheaper and buy lots of fuel; however, it will never "pay for itself" with utility savings over time. You will also need a bigger generator to charge your batteries through the EG4 in case of both power outage AND insufficient sun.

 

[Partimewages]

Y said you have a small house. Maybe do an energy study/calculation to see where you might save some energy.

 

[millsan1]

Can't comment on your particular situation, but here are my observations since I just wen through this.

I was quoted anywhere from $70-100K, without batteries.

I ended up doing it DIY, and hiring an electrician to do the heavy stuff.

I also ended up with enough batteries to hold my house for more than a day.

Total, around $45K, minus 35% tax rebate = around $30K.

The system I installed is bigger, more robust, does grid backfeed, and has batteries that act as a quiet generator.

Without batteries, solar panels do not provide to the house in the case of a power outage.

 

[maclover1]

Correct.



55kWh/day.

You can almost certainly count on 5 solar hours / day:

55kWh/5 = 11kW

28 * 400W panels = 11.2kW

So, you are set to meet your average daily consumption with the selected PV



Yes. It can also be used as a backup, i.e., not actually interacting with grid - simply drawing from it of you run out of PV or battery power.... Think of it as "off grid with grid backup."



Always. Consult the manuals.

You definitely need more than 10kWh of batteries. Generally speaking, you want battery capacity equal to your daily consumption, so you can survive 24 hours without charging. Recommend 11 batteries based on 55kWh consumption.

EDIT: didn't realize the PowerPro were about 14kWh. You'll need 4, not 11.



Fine.



Not from FL.

If you want power when grid-down, you can't rely on just grid-tie. Period.

A bigger generator will absolutely, positively be substantially cheaper and buy lots of fuel; however, it will never "pay for itself" with utility savings over time. You will also need a bigger generator to charge your batteries through the EG4 in case of both power outage AND insufficient sun.

Thanks Sunshine! This is what I've been looking for for weeks. So, in regards to the batteries, at this moment we cannot afford more- would the 2 we were thinking about allow us to run the house thru the night as it would mostly be used for the AC/furnace, some LED lights (which are not used all night), server and router and on occasion the water system (well pump and RO pump which only run for maybe 1 hour, if that)?

 

[maclover1]

Y said you have a small house. Maybe do an energy study/calculation to see where you might save some energy.

Yeah, I know it is a lot. We have a well pump, water system pumps (2), pool pump, pool heater and 2 boys who love to leave the lights on every room they go to...lol

 

[maclover1]

Can't comment on your particular situation, but here are my observations since I just wen through this.

I was quoted anywhere from $70-100K, without batteries.

I ended up doing it DIY, and hiring an electrician to do the heavy stuff.

I also ended up with enough batteries to hold my house for more than a day.

Total, around $45K, minus 35% tax rebate = around $30K.

The system I installed is bigger, more robust, does grid backfeed, and has batteries that act as a quiet generator.

Without batteries, solar panels do not provide to the house in the case of a power outage.

That's great, congrats! So, the system cannot be used during outage, even if you had the batteries installed?

 

[sunshine_eggo]

Thanks Sunshine! This is what I've been looking for for weeks. So, in regards to the batteries, at this moment we cannot afford more- would the 2 we were thinking about allow us to run the house thru the night as it would mostly be used for the AC/furnace, some LED lights (which are not used all night), server and router and on occasion the water system (well pump and RO pump which only run for maybe 1 hour, if that)?

It just depends on how much power you consume overnight and/or in excess of what PV can supply in the moment.

You can potentially take conservative steps to shift usage to PV hours.

28kWh might do it.

 

[Partimewages]

All those motors are going to present some problems if they start and run together. Get as much name plate data as possible and figure out how many hours a day they each run.

 

[Hedges]

Without batteries, solar panels do not provide to the house in the case of a power outage.

Except for some that offer batteryless backup. Could be enough to keep your refrigerator working and other essentials.

SMA Sunny Boy provides 120V 15A.
Others like SolArk I think deliver their full power at 120/240V, but of course only with enough sun. This could take care of modest size well pump.

With 4x automotive starting batteries, the surge of larger motors could be handled. In that case, be sure to set a high low-voltage cutout (and delay, allowing starting surge) so you don't kill the batteries by draining them each night. (We've heard from someone who successfully used the batteries to start a larger motor. Whether suitable discharge protection can be set, I don't know. Just my theory it should be possible.)

If you use lithium batteries, they need to be sized for the surge current, so undersizing them is limited. You'll probably end up installing a decent size bank.

Here is a bundle you may like, a large UL listed ESS from EG4. The fact it is outdoor rated makes it particularly attractive:

EG4® PowerPro UL9540 ESS - EG4 Electronics

EG4 Electronics

eg4electronics.com

 

[millsan1]

That's great, congrats! So, the system cannot be used during outage, even if you had the batteries installed?

With batteries you are good, assuming a Hybrid or on grid inverter.

Re: your questions about running on batteries, let's assume your 51 KWH use is completely even throughout the day. That is a bit over 2 KWH per hour. 2 Power Pro batteries = 28 KWH. You should leave some reserve, so call that 10% or close to 3 KWH. That makes about 25 usable. That would give you about 11.5 hours of running on batteries.

 

[Bobguy]

I'm in the Caribbean and had a 6kw system and 13.5kw Tesla power wall at last house. We didn't use a lot of power and 13.5 kw battery was not usually enough to get through the night with a single mini-split on. But my electric bill was always near nothing because it was just for a couple hours in the morning. I'm not selling back to the grid.

However, I just purchased a new system. Going for 9kW and 27kW of battery storage. That will get me through the night on at least the bedroom AC and maybe the kids room. Ideally would like to add another 13.5 battery in the future and maybe a few more kW. Also went with a Sol-Ark 15kW inverter this time so that in the event of a big storm with days of clouds can also charge the batteries on the generator. For our size family two adults and one kid I think this seems to work.

I just purchased the batteries (SOK rack) and inverter from Currentelectric for $16,600 taxes and delivery (Miami). The QCell solar panels got from Santan for like $3000 taxes and delivery to (Miami). There were some deals for thanksgiving. After tax under $15,000 to say goodbye to my crappy electric company. Can't wait.