Solar Panel Batteries & Additional Panel Installation

ndmaynard

New member
Hello All-

We were given an option to buy or lease solar panels on a new home build, and went with the Buy option to avoid issues if we decide to sell the home later.  I am new to solar energy so would appreciate any input on the below questions as well as any general recommendations/guidance to keep in mind.

Does anyone have recommendations for solar batteries?
Has anyone elected to install additional solar panels above and beyond what came with their home build?  Is it easy to integrate other panels or would we have to continue to buy from the builder's solar company?

We plan to wait for a year to assess our energy consumption patterns compared to the solar generation, but I am interested to explore options to add additional panels if pricing keeps going down and/or solar tax incentives get extended.

Thanks
 
Smart move, I tell all of my buyers to purchase their solar systems on their new homes.  I'd be curious to learn did additional solar panels can be added to an existing system.
 
I don't have personal experience, but from my research and understanding, adding additional solar panels later is not just throwing up extra solar panels. Have to take into consideration how much inverter is rated for. If you add more solar panels, you might need a bigger inverter. But then, my bet is the new company isn't going to want to replace your existing inverter due to warranty liability. If your solar system goes down, who is responsible for the warranty call, 1st installer or 2nd installer? I believe there's a house in my neighborhood that got solar panels installed at 2 different times. I'm pretty sure they have 2 inverter boxes on the side of their house. If you don't care about extra boxes on the side of your house, then I'd say you can have 2 separate systems installed, but they likely won't be tied together.

If you get the same company who did the first install to add panels later, that might be a separate story...
 
Dr. CA Real Estate said:
Always buy the system.

For storage I mostly have experience with the Tesla power wall system which has never given me trouble on any homes.

Nice - how many Power Walls did you install?  I was looking at this last night and Tesla recommends 2-3.  I've seen speculation that Powerwall 3 will be announced this year so maybe I'll wait.
 
Most panels nowdays install microinverters...meaning each panel has it's own micro inverters and pipes are just collecting all the current an hooks up to grid.

I'd imagine it should be fairly straightforward to install additional panels down the road and just connect them to the main pipe.
 
IIRC, I asked about this a couple years ago, back then the solar installer said you can add on the newer panels/inverters, but since they're all connected, the max you can generate is the lowest amount (most likely at the older panels rate).  Not sure if that has changed, panels today are more efficient than when I bought mine.  Maybe one day it's double the efficiency where I can replace the existing ones that cover the same footprint on the roof...
 
AW said:
IIRC, I asked about this a couple years ago, back then the solar installer said you can add on the newer panels/inverters, but since they're all connected, the max you can generate is the lowest amount (most likely at the older panels rate).  Not sure if that has changed, panels today are more efficient than when I bought mine.  Maybe one day it's double the efficiency where I can replace the existing ones that cover the same footprint on the roof...

Echo'ing what Cornflakes stated, if it's microinverters at each panel, you can add pretty easily, but if they use a string, then yes, your output % is your least efficient panel and they have a maximum amount, so you may need a 2nd string inverter.
 
ndmaynard said:
Dr. CA Real Estate said:
Always buy the system.

For storage I mostly have experience with the Tesla power wall system which has never given me trouble on any homes.

Nice - how many Power Walls did you install?  I was looking at this last night and Tesla recommends 2-3.  I've seen speculation that Powerwall 3 will be announced this year so maybe I'll wait.

Always happy to help a Domer (assuming that by your screen name). We installed 3 PWs to accommodate whole house backup with AC. I'm 100% self powered with solar offset getting paid at very high PG&E rates, cancelling out any gas charges.  26% fed tax credit last year reduced to 22% this year (non-refundable). Having total electricity security became a priority for me, and we got the whole system for the price of a base Model 3.
 
OCtoSV said:
ndmaynard said:
Dr. CA Real Estate said:
Always buy the system.

For storage I mostly have experience with the Tesla power wall system which has never given me trouble on any homes.

Nice - how many Power Walls did you install?  I was looking at this last night and Tesla recommends 2-3.  I've seen speculation that Powerwall 3 will be announced this year so maybe I'll wait.

Always happy to help a Domer (assuming that by your screen name). We installed 3 PWs to accommodate whole house backup with AC. I'm 100% self powered with solar offset getting paid at very high PG&E rates, cancelling out any gas charges.  26% fed tax credit last year reduced to 22% this year (non-refundable). Having total electricity security became a priority for me, and we got the whole system for the price of a base Model 3.


Thanks - Would you recommend getting 3 PW?  Have you done a cost/benefit assessment of the credits you are earning from PG&E vs. the cost? 

The price quote is about $14K (after tax incentives) for 2 PW, and $19K (after incentive) for 3 PW.

Also did you install additional panels above and beyond the standard install?
 
The 26% fed tax credit actually got extended through the end of 2022 earlier this year.

OCtoSV said:
ndmaynard said:
Dr. CA Real Estate said:
Always buy the system.

For storage I mostly have experience with the Tesla power wall system which has never given me trouble on any homes.

Nice - how many Power Walls did you install?  I was looking at this last night and Tesla recommends 2-3.  I've seen speculation that Powerwall 3 will be announced this year so maybe I'll wait.

Always happy to help a Domer (assuming that by your screen name). We installed 3 PWs to accommodate whole house backup with AC. I'm 100% self powered with solar offset getting paid at very high PG&E rates, cancelling out any gas charges.  26% fed tax credit last year reduced to 22% this year (non-refundable). Having total electricity security became a priority for me, and we got the whole system for the price of a base Model 3.
 
hurijo said:
The 26% fed tax credit actually got extended through the end of 2022 earlier this year.

Thank you for this information!

Time to really look into it, for us what happened in Texas in addition of the previous summer power cuts is making us consider it more seriously.
 
ndmaynard said:
OCtoSV said:
ndmaynard said:
Dr. CA Real Estate said:
Always buy the system.

For storage I mostly have experience with the Tesla power wall system which has never given me trouble on any homes.

Nice - how many Power Walls did you install?  I was looking at this last night and Tesla recommends 2-3.  I've seen speculation that Powerwall 3 will be announced this year so maybe I'll wait.

Always happy to help a Domer (assuming that by your screen name). We installed 3 PWs to accommodate whole house backup with AC. I'm 100% self powered with solar offset getting paid at very high PG&E rates, cancelling out any gas charges.  26% fed tax credit last year reduced to 22% this year (non-refundable). Having total electricity security became a priority for me, and we got the whole system for the price of a base Model 3.


Thanks - Would you recommend getting 3 PW?  Have you done a cost/benefit assessment of the credits you are earning from PG&E vs. the cost? 

The price quote is about $14K (after tax incentives) for 2 PW, and $19K (after incentive) for 3 PW.

Also did you install additional panels above and beyond the standard install?
I didn't do the analysis - just realized it was my only option to ensure backup power given I can't get a nat gas Generac type whole house backup generator permitted where I live. I firmly believe we will see greater frequency of intermittent blackouts across CA in the future and I also felt it would be the highest ROI investment I could make in my property - 100% energy self sufficiency with multiple days of backup.
 
If you're looking for arbitrage with a Powerwall, it never makes sense and the ROI isn't there. If you're looking for security of having backup power then yes there is value there.

Trust me I've done the analysis every which way with generous assumptions. The breakeven never made sense.
 
I was driving by on I-8 and saw a huge solar farm by Calexico. It is impressive. Turns out, they put 3 MM panels and the project cost around $300+ MM, which brings $122/panel installed.

Contrast that with the panels I put on my roof a year ago at ~$850 per panel.

The stark difference in wholesale vs retail price, like anything else we buy.
 
Cares said:
If you're looking for arbitrage with a Powerwall, it never makes sense and the ROI isn't there. If you're looking for security of having backup power then yes there is value there.

Trust me I've done the analysis every which way with generous assumptions. The breakeven never made sense.

I thought Powerwall was expensive. But after Tesla couldn't install on our roof, I got a quote from a competitor Sunpower, who wanted $16k for a battery!! Twice a Powerwall. I couldn't believe it.
 
Out of curiosity, what was the model of that battery?

I?ve looked for Powerwall alternatives but I have yet to find one with similar capacity.
 
So,

what is the appeal of powerwall for solar owners? In stead of feeding excess energy during daytime to grid, feed the battery and use the juice in evening hours before pulling power from the grid?

With NEM, does it really save enough $ to justify the cost of powerwall?
 
Cornflakes said:
So,

what is the appeal of powerwall for solar owners? In stead of feeding excess energy during daytime to grid, feed the battery and use the juice in evening hours before pulling power from the grid?

With NEM, does it really save enough $ to justify the cost of powerwall?

I didn't crunch any numbers, but I think Cares had previously mentioned it doesn't justify the costs, maybe when batteries have higher capacities and pricing comes down there will be a better breakeven point.  If someone is doing it for blackouts it makes sense, there is no breakeven, it's their use case, but if it's just to store and use from 4pm-9pm or something like that, not worth it yet, may be better to put that $ towards even more panels and ensure you'll always be net positive at the end of your cycle if you're not already.
 
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