Planning the (permitted) system upgrade for my house

[HighTechLab]

Last week, I closed on a new house in Las Vegas, NV...This is after living in RV's for years and renting a house for a year while getting financials in order. This has been years in the works and we finally got to this point right before interest rates skyrocketed.

Details of home & existing equipment:
The home is 2700sqft single story. It is fed by a 225A service and has panels installed on the roof already are 20x 255 watt panels that were installed around 2012/2013 that have microinverters for each panel. This weekend we had perfect sun on clean panels, and measuring the feed to the panels we were only receiving 10A@240v, so around 2400w out of a system that should be producing closer to 5000w. My suspicion is the panels are degraded and a few of the Microinverters have let out the magic smoke, as is a common issue with Microinverters of this vintage.

Electrical Notes:
The service panel is a meter/main combo on the exterior of the home. In other words, there is a utility meter and 225A main breaker only, that then feeds onward to the main panel with 1/0 copper wire (seemed undersized per NEC for 225A). If you are wondering what's going on in this photo, the 4 wires entering in the back corner are the feed from the existing PV, and the wires in the front go to the pool equipment. The wires feed through the wall from here into the panel that is on the opposite side of the wall.




Planned System
Since this home so conveniently has separated the main breaker from the main panel, I would love to insert a Sol-Ark 15K in between the two. I would just need to run some conduit to the panel and run the wire to & from the Sol-Ark. About as easy as it gets.

From there, we could replace the existing panels on the roof, or add more panels on the huge roof surface that is currently sitting bare.




Current Usage:
So far we have only lived here a few days and already see where things are going. We are averaging around 180 kWh per day with peaks so far of 230 kWh. The two of us living here each have an EV to charge that we've been charging at the other house throughout the process of moving, so these numbers don't fully represent the whole picture yet. The house is using gas appliances, for reference. Also worth noting in the photo below, none of the PV ever makes it back to the grid!



As mentioned, we will get this system permitted and inspected, so this thread will be great to follow along through the process.

Oh and we would be adding batteries as well, however many SOK 48v's we can fit in a 2 meter tall rack.

 

[Solar Guy Richard]

Glad you got in before interest rates went nuts! Me and my wife bought in 2020 at 2.5% interest and are looking at selling and purchasing a different home at 5.5%. Will definitely be putting a huge down payment and trying to buy down the rate as much as possible!

 

[moonlight23]

We are averaging around 180 kWh per day with peaks so far of 230 kWh... The house is using gas appliances, for reference...

Other than A/C and partial EV charging, you guys must be mining crypto.

PS - congrats on the new home :] just got a house myself, fighting other buyers and interest rates was rough

 

[Hedges]

Some PV panels degrade a little, some badly. I found that measuring Vmp & Imp (actually I measured V(load) and I(load) into a couple paralleled space heaters) identified bad panels not detected by Voc and Isc.

What efficiency panels? My older ones are 12%, newer are 20%. You get 50% more power from area of existing mounts by upgrading panels (and 30% tax credit for your new system.)

You have 5kW, want about 50kW. But your East/South/West roof faces are closer to 20% occupied, not just 10%. maybe need an awning to the South.

I suggest not inserting SolArk before existing panel (at least not without a transfer switch.) Instead, make a "Y" branch off to SolArk then to protected loads panel. Add manually switched interlocked "Generator" breaker to main panel to feed it from SolArk. Your system probably isn't large enough to power everything from PV and battery, so this lets you power important loads and turn off ridiculous ones.

Another "critical" loads panel separate from "important" backed loads would be good. Can you use the "generator" port of SolArk with its relay disconnect to shed less critical loads automatically, keep critical loads running?

 

[rogerdw]

Current Usage:
We are averaging around 180 kWh per day with peaks so far of 230 kWh.

FAR OUT!!!

Are those numbers right?

Our latest bill shows our average daily use over the last 3 months at 21.57kWh ... and a total for the 3 months at $874.39.

So if we were burning that much energy, our quarterly bill would be up around $8,000 ... and $32,000 for the year.

I'm starting to believe people when they say that South Australia has some of the highest electricity rates in the world.

 

[HighTechLab]

Other than A/C and partial EV charging, you guys must be mining crypto.

Nope, just air conditioning in the desert and the pool so far.

This rate was before charging EVs, my partner and I drive around 120 miles per day so it won't add too much demand...

The first big upgrade on the house (this system aside) is some new AC's. The units installed now still run on R22!

 

[sunshine_eggo]

I have 2300sqft in Phoenix, and we rarely bust 120kWh/day. I HATE being hot (I'm fat). 7 year old Goodman 14 SEER unit.

New A/C should make a huge difference. Have you measured the actual consumption while running with a clamp ammeter?

 

[Goboatingnow]

Wow 200 units a day , here at about 35 euro cents €70 a day , €2100 a month , wow. , my electricity bill , and I run a EV charged from the grid at night. My bills run about €80 a month

 

[Nobodybusiness]

I have 2300sqft in Phoenix, and we rarely bust 120kWh/day. I HATE being hot (I'm fat). 7 year old Goodman 14 SEER unit.

New A/C should make a huge difference. Have you measured the actual consumption while running with a clamp ammeter?

I can tell you from experience the higher seer units are worth it over the long run.

Went from a 2002 TRANE 2 ton 10 seer to a MR cool 2 ton 20 seer and the reduction is noticeable.

 

[HighTechLab]

I can tell you from experience the higher seer units are worth it over the long run.

Went from a 2002 TRANE 2 ton 10 seer to a MR cool 2 ton 20 seer and the reduction is noticeable.

We plan to also upgrade our AC units. I'm going to be checking the charge today, I think the main unit is low on charge. Would really rather not buy R22 refrigerant at over $300 for a 5lb tank

 

[HighTechLab]

I have 2300sqft in Phoenix, and we rarely bust 120kWh/day. I HATE being hot (I'm fat). 7 year old Goodman 14 SEER unit.

New A/C should make a huge difference. Have you measured the actual consumption while running with a clamp ammeter?

the main AC is about 14 amps and the small one is about 9 amps (both at 240v)

I also found the existing solar was only generating about 10A in peak sun. Climbed on the roof and found the panels are 255w panels, so we should be getting closer to 20-25A out of them. My thought is that the panels are likely degraded and some of the microinverters are popped.

 

[sunshine_eggo]

the main AC is about 14 amps and the small one is about 9 amps (both at 240v)

I also found the existing solar was only generating about 10A in peak sun. Climbed on the roof and found the panels are 255w panels, so we should be getting closer to 20-25A out of them. My thought is that the panels are likely degraded and some of the microinverters are popped.

What-the-hell-else are you powering???? Even if those two units are running 24/7, they only amount to 144kWh.

 

[jberger]

Congratulations on the new home, look forward to learning as you install your new gear on the new place.

 

[Wet1]

That amount of consumption seems insane, I think my first order of business would be to drastically reduce that!

 

[Quattrohead]

Emporia for the win

 

[Wet1]

Emporia for the win

Check the specs first to make sure it can handle that many amps w/o letting the magic smoke out!

 

[HighTechLab]

yesterday was brutal. The AC's started at about 8am at which point they never stopped until after I was already asleep.
When our indoor temperature was about 6 degrees above thermostat setting, I went to check the outdoor units...The thermocouple on my Fluke was reading 122F ambient on the back patio!!!

I think the one AC unit is overcharged because it has about 30 degrees of subcooling, but I didn't really want to touch it because that unit was kicking butt and doing a good job. The other unit had 13 degrees subcooling (proper charge) but was falling behind and frosting up (with good airflow). I think the TXV on the evaporator may be toast.

These AC units are beat down. We may have to delay the solar install for getting these replaced with higher SEER (and probably tonnage) units. First, we are working on getting some blinds for the windows, because they are all missing and I feel like the sun coming in is pouring a LOT of heat into the house.

The Lennox Signature XC25 units look nice...26 SEER on a central HVAC unit is incredible.

 

[HighTechLab]

 

[Wet1]

That's insane for just AC and a pool pump! Getting the sunlight out of the house is an excellent and inexpensive start. You might want to also check to see if the pool pump is running longer than it needs to be. Baby steps!

 

[Hedges]

Pool pump probably consumes more power per gallon at higher flow rates, due to more back pressure. Consider variable speed.


Years ago I installed a 3-phase motor on my pump and connected a VFD.
Variable-speed pool pumps are now available with the VFD built in, and have features like detecting obstructed input (somebody stuck to inlet) trigging shutoff.

My VFD has simple diode/capacitor front end. That draws higher RMS current for the same power; previously had 15A 230V breaker for 2 HP pump, now 20A but trips on a hot day if running max speed. One with PF corrected front end would be preferred. (Everything has a degree of complexity to consider.)