Too many panels for PW2?
I have a deposit in for a single PW2, I did all the pics and answered all the questions... after a few months I got my estimate:
4 power walls for $26,869 (whole house backup)
or
2 power walls for $27,679 (they said they would have to rewire my house)
No one has been to my house to look at anything, this is only from the pics requested that I sent them and the only explanation they could give me was that I have too much solar. I have 9.7k on the roof, and only want a partial backup, 1 PW.
Has anyone else run into the "too much solar" problem for the powerwall? I figured once the battery was charged any excess production would be net metered like it is now. I need someone versed in this to help because the Tesla reps on the phone only read whats on their screen, Im looking for the limitation explanation.
4 power walls for $26,869 (whole house backup)
or
2 power walls for $27,679 (they said they would have to rewire my house)
No one has been to my house to look at anything, this is only from the pics requested that I sent them and the only explanation they could give me was that I have too much solar. I have 9.7k on the roof, and only want a partial backup, 1 PW.
Has anyone else run into the "too much solar" problem for the powerwall? I figured once the battery was charged any excess production would be net metered like it is now. I need someone versed in this to help because the Tesla reps on the phone only read whats on their screen, Im looking for the limitation explanation.
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If you go with a 1 PW2 installation, you would be limited to 13.5 kWh in backup storage which should be enough to keep your lights on and refrigerator running, etc. I certainly don't understand the logic that you would have to rewire you home for a 2 PW2 system. You definitely don't have too much solar IMHO. I would request Tesla-Energy send a Tesla rep out to your home for an in depth assessment. I am still waiting to get my estimate and an installation date for my PW2 system.
We live ~1mile from the Gulf of Mexico just north of Clearwater FL. Our house uses 1100-1700kwh per month with solar production of ~1100 per mo. We sell back (wholesale) every day the sun is out but buy it back (retail) at night. Looking to power the house at night and in the unlikely event of a hurricane, power the inverters so the solar will charge the PW and power essentials in the house while waiting for the power co to restore service. but our goal is to use the battery daily as opposed to a stand-by generator that only gets used in an emergency.
The PW has no apparent issue with hitting 100% full and relatively gracefully stopping charging.
So I can see no problem with your single PW solution. Of course, just one would not permit you to reserve much for backup.
I will certainly be buying another PW once the backup gateway becomes available here in the UK.
Thank You both for responding...
Any others with larger PV systems and a single PW?
The PV system survived the storms without a scratch (which is surprising since the roof blew off my neighbors house, and landed 2 acres away in my yard). Thankfully, when we installed the PV system, we opted for the "secure power supply", which allowed us to pull about 3kW of unconditioned energy off of our system during daylight hours. After living like that for 163 days, we were itching to get a storage solution.
We put a deposit down on a PowerWall 2 about a month ago, and the installation (one PW2 + backup gateway) was completed this past Wednesday.
Our PV system is 48 panels, split into 2 arrays of 24, with each array going into its own inverter (SunnyBoy).
The way they decided to hook it us was to send the AC from 1 inverter (6kW) to the PW, and the leave the other inverter grid-tied. My Backup Gateway only sees the 6kW from the 1 inverter. The other inverter comes into the Gateway on the "grid" terminals ... so those terminals contain a mix of solar and grid energy.
On the first day, the PW charged from 16% (that was the charge out of the box) to 100% within the day, so obviously the 6kW coming from the 1 inverter is enough to feed the PW, my house, and even export back to the grid.
My issue is that, in the case of a grid outage, the second inverter (the one NOT connected to the PW) will shut down, and be of no use to me. My concern is not a short outage (those are part of normal life here in PR). It's with another long-term outage ... I want use of the whole 12kW on my roof during the day. I'm fine cutting my consumption back at night ... but when the sun is shining ...
This set-up was not explained to me beforehand. I was told by the sales rep that I _would_ have full use of the 12kW during the day during an outage ... we're still fighting about that.
Anyway ... the reason I was given for only taking the 6kW from the 1 inverter is because the PW cannot handle the full 12kW. They say ideally the PW wants 6kW to about 9kW .... not sure. I don't fully understand all this stuff yet. But certainly, I'm being told that my PV system is "too much" for the PW.
We are located in Tampa Bay as well - Tierra Verde area near St. Pete Beach. Our 14kW solar PV generator was installed over two years ago before the PW2 hit the market. At that time a battery system didn't seem like a priority given our relatively low energy cost and the high grid reliability in this area.
When PW2 hit the market it seemed like a game changer for several reasons, so I'm now doing more research on possible use cases in preparation for installing a few PW2s on this home. Definitely planning to install them on future homes. I'm actually heading down to International Mall today to see the showroom M3 (I'm a reservation holder) and will look for Caleb Suwak - thanks for the referral.
A few quick questions please:
- Are your combined generator/PW2 systems setup to run your entire house load in the event of a grid failure?
- When the grid fails does the combined system work like a "whole-house UPS", automatically switching over to power the house from the inverters and PW2s while grid is down?
- If so, how long does the switch-over really take? I've read posts from early users saying it can be instantaneous, so fast that a PC would not reboot after the switch. Has that been your experience?
- Any chance of getting a look at your systems sometime?
Thanks in advance. I can be reached: patrick at aeropartners dot com or eight one three, three nine zero, seven one zero nine.
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- Are your combined generator/PW2 systems setup to run your entire house load in the event of a grid failure?
Yes
- When the grid fails does the combined system work like a "whole-house UPS", automatically switching over to power the house from the inverters and PW2s while grid is down?
Yes, this has happened twice.
- If so, how long does the switch-over really take? I've read posts from early users saying it can be instantaneous, so fast that a PC would not reboot after the switch. Has that been your experience?
It happened so fast that I was not aware the the grid was down.
- Any chance of getting a look at your systems sometime?
I am in Dade City, Fl. I have a 10.5 kwh system with 2 Powerwalls.
Thanks in advance. I can be reached: patrick at aeropartners dot com or eight one three, three nine zero, seven one zero nine.
Just curious - which energy company do you use? Any idea if or how much they will pay you for all your extra generation and when?
We have also done extensive energy reduction retrofits to our 1987 home which have dramatically reduced our energy demand. We also swapped out our gas furnace and gas water heater for electric heat pump and heat pump water heater, so we are 100 percent electric. Our electric use during the summer is very small (generally less than 9 kWh/day), and as an example only averaged 2.6 kWh/day last month as a reference point, and our solar production averaged 60 kWh/day for May 2018. Last year we were 182 percent (solar production/energy demand), which covered our home and EV charging requirements, while exporting all the excess solar back to grid. I have attached link to that certification, which provides a summary of what we have done here. With the PW2 installation we exported yesterday 75 percent of our solar yesterday back to grid, so we are way good this time of year. We do not produce enough solar during November, December, and January to cover our energy loads, but do the remaining 9 months of the year. We have been Net Positive for past six years and our home was certified as a Net Zero Energy Building (NZEB) by the International Living Future Institute in 2016.
https://living-future.org/lbc/case-studies/sustainable-dreams/