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Solar Panels only generating about 60% [of peak production number]

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I wondered about the ease of the add, often. It would make some sense if, at least in part, PG&E's views change depending on local variables, such as how much power does the customer use in a day/month/year (@h2ofun clearly has a track record of high usage, as his powerwalls don't last very long), current infrastructure (transformers, HV supply lines), local demand, and how many folks already have solar. I am not saying that they are always logical, far from, as their track record demonstrates, but I am open to the possibility that there are some parts that might be.

(I think you (@holeydonut) just drew the short straw, and got someone really cranky. Sorry. But it makes for great stories around the campfire, "...then the inspector of all things electrical past appeared to me, dragging his chains and disconnect boxes, and drew me onward to see the melting batteries with no disconnects... Gasp!")

All the best,

BG
Actually, my current use for the last year, with PW's, is even smaller than my first 15kw of panels. I gave them my usage from over 2 years ago, before batteries or solar, which was off the scale because I was using 10 wall heaters.
 
Actually, my current use for the last year, with PW's, is even smaller than my first 15kw of panels. I gave them my usage from over 2 years ago, before batteries or solar, which was off the scale because I was using 10 wall heaters.
Exactly, so from PG&E's perspective, they have liberated some power capacity locally, which is probably worth no small amount of money to them.

I look at PG&E's costs sometimes, and it does seem like the amortization has to be out decades. When they replaced our transformers, the hourly labor costs for the crew was well north of $700/hr, plus the truck time, and equipment costs...and it took them six hours on site. You can easily see why solar can be such a headache for them, with large surges during sunny days. Getting someone with five batteries to push that surge late in the day must be awesome, not to mention not being a load for most or all of the day.

All the best,

BG
 
Exactly, so from PG&E's perspective, they have liberated some power capacity locally, which is probably worth no small amount of money to them.

I look at PG&E's costs sometimes, and it does seem like the amortization has to be out decades. When they replaced our transformers, the hourly labor costs for the crew was well north of $700/hr, plus the truck time, and equipment costs...and it took them six hours on site. You can easily see why solar can be such a headache for them, with large surges during sunny days. Getting someone with five batteries to push that surge late in the day must be awesome, not to mention not being a load for most or all of the day.

All the best,

BG


I completely agree with what you're saying, but I continue to be amazed at how easily the CPUC is buying into the notion that H2ofun is harming the grid, and in particular poor people without solar.

PG&E basically argues that h2ofun is not paying to use the infrastructure of transformers, power lines, and trenching, etc to get electricity to his home. So instead every kWh of power he exports to the grid harms poor people since now others have to pay for his grid access.

Of course the part that PG&E is leaving out is that the reason h2ofun is "harming PG&E ratepayers" is because PG&E couldn't take a guaranteed profit on investing in h2ofun's system. So PG&E loses the investment/amortization of his solar assets; plus PG&E misses out on his recurring payments for outrageously priced energy. But instead PG&E paints homeowners like h2ofun as wealthy fat cats that are sticking it to Californians. Total BS argument but the CPUC seems intent on believing that argument since they're rather corrupt and benefit from having PG&E remain a large "IOU" (monopoly) that requires the CPUC to provide oversight.
 
I completely agree with what you're saying, but I continue to be amazed at how easily the CPUC is buying into the notion that H2ofun is harming the grid, and in particular poor people without solar.

PG&E basically argues that h2ofun is not paying to use the infrastructure of transformers, power lines, and trenching, etc to get electricity to his home. So instead every kWh of power he exports to the grid harms poor people since now others have to pay for his grid access.

Of course the part that PG&E is leaving out is that the reason h2ofun is "harming PG&E ratepayers" is because PG&E couldn't take a guaranteed profit on investing in h2ofun's system. So PG&E loses the investment/amortization of his solar assets; plus PG&E misses out on his recurring payments for outrageously priced energy. But instead PG&E paints homeowners like h2ofun as wealthy fat cats that are sticking it to Californians. Total BS argument but the CPUC seems intent on believing that argument since they're rather corrupt and benefit from having PG&E remain a large "IOU" (monopoly) that requires the CPUC to provide oversight.
And for what is cost me to put all this solar on, so I could be a good green person and try to help the power not going out for those "poor" folks, .....

On one hand they put a bunch of rules in place to force people to go green, like all new houses have added cost for solar panels, but when folks like you and I spend our own money to try to support these goals, well, their profits at the end of the day, not matter how poorly the company is run, is all the matters, since the CPUC guarantees them a minimum amount.

typical government stuff, at the end of the day, us little people at the pawns.
 
And for what is cost me to put all this solar on, so I could be a good green person and try to help the power not going out for those "poor" folks, .....

On one hand they put a bunch of rules in place to force people to go green, like all new houses have added cost for solar panels, but when folks like you and I spend our own money to try to support these goals, well, their profits at the end of the day, not matter how poorly the company is run, is all the matters, since the CPUC guarantees them a minimum amount.

typical government stuff, at the end of the day, us little people at the pawns.


Yeah, the scam is how this NEM thing allows PG&E to deflect attention away into some weird rich vs poor thing. So people will ignore how poorly PG&E is managed, how many people PG&E kills each year, and how inefficient PG&E is compared to every other energy utility operating in the USA.

Our policymakers and the CPUC seem to think solar net metering is much worse than PG&E continuing to make corrupt business decisions, terrible investment meant to get money to grifts, and "resource allocation" that would get leaders at normal "investor owned companies" fired/arrested.

Seems rather convenient that when the CPUC paid E3 to learn about solar net metering, E3 came up with a position that is 100% aligned with what PG&E wants. Somehow residential rooftop solar basically helps zero people from noon to 3pm except the homeowner with the panels.
 
I think the OP might not be clear on the concept that each Powerwall includes an inverter so it can output AC power, but the replies here are not talking about the inverters in the Powerwalls. They are talking about the solar inverter. If you have a Powerwall+, the solar inverter is the box on top. Otherwise, it's a separate box.


I didn't really follow that Powerwall+ thread very well... but is the new Powerwall+ DC coupled to the solar?

That is, do the solar and battery portion of the "+" exist on the same side of the inverter? To the extent the combination of DC is managed by some controller, and then the DC is exported through the single inverter as necessary to power the home or export back to the grid?

This is similar to how a Generac PWRCELL works where the solar and battery are DC coupled and all green energy has to go through the inverter to make it into the home or the grid.
 
I didn't really follow that Powerwall+ thread very well... but is the new Powerwall+ DC coupled to the solar?

That is, do the solar and battery portion of the "+" exist on the same side of the inverter? To the extent the combination of DC is managed by some controller, and then the DC is exported through the single inverter as necessary to power the home or export back to the grid?

This is similar to how a Generac PWRCELL works where the solar and battery are DC coupled and all green energy has to go through the inverter to make it into the home or the grid.
My understanding is that the new PowerWall + is still AC coupled. It looks to me like it is just a regular PowerWall with a horizontal solar inverter on top. My understanding is probably too simplistic though. I think the new solar inverter also has some of the logic of the gateway in it. This allows the new power meter collar switch thing to simplify installation. Where that can not be used, a gateway is installed, but it is remote controlled from the solar inverter.

Did I get that right?
 
My understanding is that the new PowerWall + is still AC coupled. It looks to me like it is just a regular PowerWall with a horizontal solar inverter on top. My understanding is probably too simplistic though. I think the new solar inverter also has some of the logic of the gateway in it. This allows the new power meter collar switch thing to simplify installation. Where that can not be used, a gateway is installed, but it is remote controlled from the solar inverter.

Did I get that right?
Your description matches my understanding. I wish the solar was DC coupled to the battery, but it seems not. Maybe in some further optimization implemented in the future.
 
I don't know that you mentioned how many inverters you have, but you could have one or two. What the other posters are referring to is that inverter size is always some fraction of system size. In my case its 16.32 kw system with two 7.6 inverters.

Those in the know would say that 15.2 inverter capacity on a 16.32 system is "more" inverter capacity than you need, but its fine by me (since I wouldn't have saved much by asking for a smaller inverter) and I plan on adding panels at some point now that I see the size of the system.

Next up, if you require 100 to 120 per day you should have gotten the largest size system in the first place. My 16.32 in so cal does not get over 100 per day all year. Sure, over 100 on the best days, but not all.

Next, next up. Your original question. Even on the days my system produces 120, it never reaches 16.32. The best hour is around 12. something. But you get to 120 by having 14 hours of daylight and maybe six hours of production over 10? Today I will get around 75 and only three hours of production were 10 or above.

Next, next, next up. Now that you don't worry about reaching the system size in terms of production, what do you, or should you, get? Its all about location of your house, roof angle, and shading, and how the panels are arranged.

Finally, your last question is sort of the least relevant. Those numbers are what the PWs can put out. Its certainly "relevant" but other than when A/C is starting up, your PWs are hopefully not outputting 15 continuously. I mean, at 15 they would only last like two hours and a bit allowing for a 20% reserve.

What actually happens is, that you will figure out what your house draws at night, average. For us its about 1.5 to 2.5 kwh. Then, do the math, ten hours of that is 15 to 25 kwh. If you have a 20 percent reserve, subtract 8 from your 40.5 and its 34. Remember, I used ten hours to make the math easy, during winter you are going to have 14 hours a day of full darkness and another hour in the morning and evening of not enough sun to power the house.

So, 14 hours at 2 kwh per hour uses up 28 of your 34 available PW.

I mean, 21kwh of surge power? I certainly hope not!

So its:

A. The size of the system has to be converted to your location and roof, then you can get estimated power production.
B. If you use 100 a day you need a big ass system. Probably need a 4th PW. Otherwise, (i) the system won't produce enough to cover house usage, and (ii) part of that means you need to fully charge the over and above house usage, so that (iii) the PWs can make it through the night, or at least the average night, or at least most of the average night.

This is why, when you look at the boards, all the people who already have solar always tell every one to just get the biggest system you can fit on the roof.

Tons of info here! Thanks. For the past few weeks, I have it set on "Time Based Control", so what happens is I start the day with Powerwalls at 25%. On a good sunny day, the panels charge the batteries and contribute some to the house, so still pulling from the grid during the morning. Then around 2 or 3 pm, the batteries hit 100% and start to discharge, so between batteries and whatever I'm getting from solar I run the house (0 from grid). Batteries are usually back down to 25% by end of day, so I go back to grid for the evening.
 
Welcome to TMC.

This is a very common question (someone asks some variation of this question at least a couple times a month). The very short version of the answer is, just because you purchased a "11.6kW" system, that doesnt mean you will ever see a peak input of 11.6kW of solar production.

Unless you have:

1. Inverter capacity rating of 11.6 or higher
2. all panels pointing in the optimum southern direction
3. Perfect pitch on your roof for maximum solar production.

You will likely never see that number (and that number isnt important, actually). Solar production is tracked over weeks and months, Not hitting 11.6 for an 11.6 system doesnt really matter for overall production.

To check your production, go to a site like pvwatts and input all your variables.

In the vast majority of these questions, it is "completely, 100% normal and expected" to not ever hit the peak number for the solar you purchased. Most dont, actually.
Hi! Ok, so does this logic apply to a system with each panel having the Enphase inverter on them with a combiner? From all the specs I've read, I could easily add more panels and not hit a capacity limit.
 
Hi! Ok, so does this logic apply to a system with each panel having the Enphase inverter on them with a combiner? From all the specs I've read, I could easily add more panels and not hit a capacity limit.

I am not familiar with that setup (I dont have micro inverters personally). With that being said, in general, system size doesnt mean you will hit that peak production number. What you might or might not be able to add depends on your exact setup.
 
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Hi! Ok, so does this logic apply to a system with each panel having the Enphase inverter on them with a combiner? From all the specs I've read, I could easily add more panels and not hit a capacity limit.
Not clear what you are asking.
Enphase uses 12ga wire to connect panels to produce 240V. And, they limit by specifying how many panels per inverter type, IQ7, 7+, etc, you can have on a 20A circuit breaker, regardless of panel size. System is designed or should be to a an DC to Ac ratio that should be over 1:1 to about 1.5 to 1 but have seen 1.7.
So, if you have multiple breakers or can add and that combiner for 2 or more, also allowed by power company, you can add whatever the electrical code may allow with your main panel rating and the rest of the house.
 
From all the specs I've read, I could easily add more panels and not hit a capacity limit.
As others have said it depends on what capacity limit you are talking about. There most likely is a capacity limit in your PTO. There is also a limit to how much your bus bar can be backfed. Finally there is a limit to how many micros per branch circuit.
 
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hmm, I'm somewhat new to learning about how the inverter caps max daily capacity. I just had a 9.2KW System installed with no powerwall. I don't have any powerwalls, and have the following two questions:
1. Am I able to be in self consumption mode until PTO (no one mentioned it to me)
2. My contract says annual production of 13,200 KWH, is that number somewhat realistic, or is that also based on sun angle, inverter clipping? I'm hoping that is the actual predicted output given the products/size and design that was installed? I based my solar system based on how many KWH I consume annually.
Thanks
 
hmm, I'm somewhat new to learning about how the inverter caps max daily capacity. I just had a 9.2KW System installed with no powerwall. I don't have any powerwalls, and have the following two questions:
1. Am I able to be in self consumption mode until PTO (no one mentioned it to me)
2. My contract says annual production of 13,200 KWH, is that number somewhat realistic, or is that also based on sun angle, inverter clipping? I'm hoping that is the actual predicted output given the products/size and design that was installed? I based my solar system based on how many KWH I consume annually.
Thanks
Well, I am not sure what size your inverter is, nor some other details but if that was the estimated production it should be pretty good.
I have a 10-year-old solar system, batteries are relatively new, and with a 3.8kW system I have produced a little over 6 mWh year over year, 6.68 mWh first full year to 6.06 mWh in 2019.
Yours is about 2x my system with what I am assuming to be a 7.6 kW inverter.
Certainly, others will chime in and give better info.
 
Well, I am not sure what size your inverter is, nor some other details but if that was the estimated production it should be pretty good.
I have a 10-year-old solar system, batteries are relatively new, and with a 3.8kW system I have produced a little over 6 mWh year over year, 6.68 mWh first full year to 6.06 mWh in 2019.
Yours is about 2x my system with what I am assuming to be a 7.6 kW inverter.
Certainly, others will chime in and give better info.
Thanks, I have tried to look through my docs, but cant seem to find the inverter size anywhere :(. I am also presuming its a 7.6KW inverter. But, honestly, as long as they are basing the est annual production based on the 9.2kw system and the installed inverter, then Im OK.