Who's gone Solar

[blrmaker]

Nice mounts make a huge difference. Super cool you're just down the road from signature solar. I assume you went there to pick everything up?

Yea just 1 1/2 hrs away. Bought one of their complete kits last year. My goal was to be completely off grid with the shop once we move into the house. The batteries do not last a full night with us living in a camper next to the shop.

 

[byke]

What do you think the issue is? 30kwh should easily get you through the night. You're probably not averaging more than 1kwh usage in the trailer, so are the batteries not getting charged enough during the day?

 

[blrmaker]

What do you think the issue is? 30kwh should easily get you through the night. You're probably not averaging more than 1kwh usage in the trailer, so are the batteries not getting charged enough during the day?

Truth is, combined between the shop and the camper, we have 3 refrigerators, 2 hot water heaters, 3 air conditioners, 1 stand up freezer, and the normal loads. Last summer I actually even used my welding machine on the pv system. I think all combined (especially the ac's) suck the batteries down. Early this spring with no air conditioners running the batteries lasted all night.

 

[byke]

Ahh gotch, you got a lot going on. Do you know what your depth of discharge is set to?

 

[blrmaker]

Ahh gotch, you got a lot going on. Do you know what your depth of discharge is set to?

Not sure. The watch power app is not clear. LOL probably something I need to figure out.

 

[byke]

If you watch those Will Prowse videos, you know he loves to go 100% -> 0% and says that calendar aging will kill the batteries before cycling will, but I think 20% is probably a common default setting, so you may be leaving some capacity on the table. And if you're diving into the settings, also check your battery PV charge current. Those 48v batts have 100ah cells, so you can charge those things at up to 100a for each battery module, potentially 600a if it were possible. I think the max charge current from that inverter is 120a and I try to stay away from max settings, so I'd stick each of the inverters at 100a and try to get 200a total charge going. Looks like the default charge rate is 50a across the board, so if you haven't changed it, that'd be a really good one to bump up. And of course keep all that in mind with whatever size power cable you're using with your batteries.

 

[blrmaker]

If you watch those Will Prowse videos, you know he loves to go 100% -> 0% and says that calendar aging will kill the batteries before cycling will, but I think 20% is probably a common default setting, so you may be leaving some capacity on the table. And if you're diving into the settings, also check your battery PV charge current. Those 48v batts have 100ah cells, so you can charge those things at up to 100a for each battery module, potentially 600a if it were possible. I think the max charge current from that inverter is 120a and I try to stay away from max settings, so I'd stick each of the inverters at 100a and try to get 200a total charge going. Looks like the default charge rate is 50a across the board, so if you haven't changed it, that'd be a really good one to bump up. And of course keep all that in mind with whatever size power cable you're using with your batteries.

Batteries are something I know very little about. I try reading the DYIsolar forum to get educated but much of it is above my head. I will look at bumping the charge rate up. Thank you!

 

[byke]

That's okay, it's likely all safe at your default settings, but if you haven't changed anything, I think you can get a lot more performance out of it. Ill help however I can, but please post any tweeks/changes/updates you make along the way, your setup is rad!

 

[blrmaker]

Well since this is a solar thread, I will post up my plans for our new home. Here is a PDF of the layout.

 

[byke]

Including the shop, that's 47k watts!

 

[blrmaker]

Including the shop, that's 47k watts!

The house will have 2 EG4 18Kpv hybrid inverters and eventually 6 EG4 wall mount indoor batteries. I have the electrician doing all of the AC side of the system and I will install all of the DC side of the system. My utility already granted our "interconnect agreement" so any excess can be put back onto the grid for credits. The inverters will be set to SBUG priority since the generator is propane driven.

Our goal is to be as independent as possible.

 

[GAJ]

At 10 months our combined electric/gas bills down an average of $302.

In that time we've replaced the following with electric vs gas before and eliminated a few electricity hogs.

Half our winter heating, moved from Plasma TV to OLED, eliminate a 75 gallon fish tank with 24 hour pump and 150 watt heating element, (fish went to the fish store to be sold on), electric Heat Pump water heater, electric dryer, electric induction cooktop and actually added a stand up freezer in the garage.

18.1 percent ROI FTW with a 6.5 year payback based on last year's electricity rates, closer to 5 years now with significantly higher electricity rates.

Oddly we produced more electricity per day in May and now June that we did last August when the panels were new and much cleaner.

Must be sun angles are better this time of year than in summer?

 

[byke]

Think they say 30 degrees in summer and 45 degrees in winter.

 

[blrmaker]

At 10 months our combined electric/gas bills down an average of $302.

In that time we've replaced the following with electric vs gas before and eliminated a few electricity hogs.

Half our winter heating, moved from Plasma TV to OLED, eliminate a 75 gallon fish tank with 24 hour pump and 150 watt heating element, (fish went to the fish store to be sold on), electric Heat Pump water heater, electric dryer, electric induction cooktop and actually added a stand up freezer in the garage.

18.1 percent ROI FTW with a 6.5 year payback based on last year's electricity rates, closer to 5 years now with significantly higher electricity rates.

Oddly we produced more electricity per day in May and now June that we did last August when the panels were new and much cleaner.

Must be sun angles are better this time of year than in summer?

PV panels are more efficient in lower temperatures. That would be my guess. Congrats on the ROI

 

[GAJ]

PV panels are more efficient in lower temperatures. That would be my guess. Congrats on the ROI

Ah, ok.

We were hardly the "ideal" candidate for solar but once the Eucalyptus trees in the cemetery were felled we noodled it but didn't pull the trigger until this thread and the looming end of Nem2.

The ROI is surprising to be honest.

If we had done it now, using last year's PGE rates, we'd still have a 9.2 year payback and 12.7 percent ROI under Nem 3 and the need for an estimated $10k batter (better numbers with lower battery cost due to rebates though).

So solar under Nem 3 is still viable for you suburban home with decent sunlight assuming of course you have the $34k+ to invest in a 20 panel system as we did.

Less if you can DYI like you did of course.

 

[GAJ]

Just finished 12 months with solar; looks like our system is right sized.



Total July 2024 Balance$18.52


Estimated Solar Charges at True-Up$26

Payback based on those numbers, not adjusted for PGE rate increases since install is 6.7 years.

Factoring in that 17 percent increase (for a whole year) reduces payback to 4.7 years.

We are under NEM2 with a total investment of $23,620 in the system.

​

 

[Climber]

Oddly we produced more electricity per day in May and now June that we did last August when the panels were new and much cleaner.

Must be sun angles are better this time of year than in summer?

The summer equinox is in late june, August is 2 months off, angle definitely makes a difference.
I think you'll find that July is better than May and not quite as good as June.

 

[GAJ]

The summer equinox is in late june, August is 2 months off, angle definitely makes a difference.
I think you'll find that July is better than May and not quite as good as June.

Thus far July is like August and May in terms of kwhr/day generated.

June was about 5 percent higher.

I'm a dummy, we only have 11 months under our belt so might have zero true up by month end.

 

[Alan_Hepburn]

We've had our system for 8 years now - 4KW system on a 1000 sq ft house. Here's our usage over the past year:

 

[tgrrdr]

I think you'll find that July is better than May and not quite as good as June.

For my system I think the weather makes more difference than the hours the sun is up. In May 2023 my system generated 1.5 MWh and May 2024 was 1.8 MWh. June (2023 and 202424) was 1.7 and July 2023 was 1.8.

My best day last June (6/19) was 62.2 kWh and my worst day (6/6) was 35.0 kWh.