PG&E said we had the potential to send back "too much" power ?

[dho112]

I purchased my Tesla Solar energy system last year, and since then have been shouting from the rooftop about how much I love the system and appreciate the energy independence, convenience, and energy security.

There are now 4 houses in my court that have solar energy systems and three more who are actively asking me questions in preparations for also going solar.

The other day, one of those neighbors approached me saying PG&E informed him that because there was an upper limit to how much electricity could be sent to the grid given our current electrical infrastructure (I'm assuming the physical makeup of the equipment that feeds our particular court electricity) and if more solar was installed in our court, they would either artificial restrict how much power each house could send back to the grid, or simply prevent any more solar from being installed at all!

I'm not certain if this is just a ploy by PG&E to further discourage rooftop solar, or if there is validity in this warning, because I can tell you, that if they just arbitrarily restrict the energy I can send back, I'm going to be VERY upset.

Has anyone else ever encountered anything even remotely like this? Because it is literally the first time I've ever heard of it...

My neighbor mentioned they said something about transformer capacity. I'll try to get more details. Our electrical delivery equipment is not ancient either. It is undergrounded and the boxes at the end of the street are very new; I'd say 8-10 years old?

 

[jjrandorin]

I purchased my Tesla Solar energy system last year, and since then have been shouting from the rooftop about how much I love the system and appreciate the energy independence, convenience, and energy security.

There are now 4 houses in my court that have solar energy systems and three more who are actively asking me questions in preparations for also going solar.

The other day, one of those neighbors approached me saying PG&E informed him that because there was an upper limit to how much electricity could be sent to the grid given our current electrical infrastructure (I'm assuming the physical makeup of the equipment that feeds our particular court electricity) and if more solar was installed in our court, they would either artificial restrict how much power each house could send back to the grid, or simply prevent any more solar from being installed at all!

I'm not certain if this is just a ploy by PG&E to further discourage rooftop solar, or if there is validity in this warning, because I can tell you, that if they just arbitrarily restrict the energy I can send back, I'm going to be VERY upset.

Has anyone else ever encountered anything even remotely like this? Because it is literally the first time I've ever heard of it...

My neighbor mentioned they said something about transformer capacity. I'll try to get more details. Our electrical delivery equipment is not ancient either. It is undergrounded and the boxes at the end of the street are very new; I'd say 8-10 years old?

Yes, thats a thing. Thats one of the main reasons why utilities require inspections / PTO, to ensure there is no issue with equipment upstream.

I believe in Hawaii new installs are not allowed to send back to the utility at all, due to this, so no, this is not some PGE ploy to discourage solar, unless you consider a desire for them to not upgrade the transformer a ploy.

 

[charlesj]

Y...., unless you consider a desire for them to not upgrade the transformer a ploy.

That could be a reason, unexpected upgrade of equipment to handle the greater load that was not planned for when that section was designed.

 

[cali8484]

If it's the street transformer then it's not unusual for the home owner requesting interconnection to get asked to pay for the upgrade.

 

[Vines]

If it's the street transformer then it's not unusual for the home owner requesting interconnection to get asked to pay for the upgrade.

It is certainly a thing that the utility can limit the solar backfeed if it will risk equipment.

My understanding is this: in PG&E territory if a transformer upgrade is required on a shared transformer, I believe PGE pays for it 100% or 95% at least.

If the transformer is dedicated to your property, then the cost of the upgrade is yours to bear, and PGE might take on a nominal sum.

In CPAU territory it is much worse, but at least there they only ask that you pay the actual equipment cost, and CPAU will pickup most or all of the labor, I think. CPAU only allows less than 20 kW of combined PV+PW to be installed before the transformer likely needs an upgrade.
Palo Alto's climate goals threatened by inadequate power grid

 

[hiltxan]

How often does this happen? Is there anyway to confirm that the transformers can handle the new solar equipment?

I’m installing mine in two weeks. Tesla wants full payment after city inspection but before PTO. If the transformer cost needs to be paid by the homeowner then it drastically changes whether or not solar is financially worth it. I’m trying to get Tesla to submit the paperwork for PTO prior to install but haven’t had any luck there either.

 

[Vines]

How often does this happen? Is there anyway to confirm that the transformers can handle the new solar equipment?

I’m installing mine in two weeks. Tesla wants full payment after city inspection but before PTO. If the transformer cost needs to be paid by the homeowner then it drastically changes whether or not solar is financially worth it. I’m trying to get Tesla to submit the paperwork for PTO prior to install but haven’t had any luck there either.

I would say it is pretty rare in my experience. maybe 1 in 50 or 1 in 100 jobs would be subject to a transformer upgrade. Still, I doubt you have a dedicated transformer in San Fransisco. Likely it is shared across a few houses and then if my information is right means PGE will pay for the upgrade.

There is no way to know this until you file for PTO, this is why we do that step as soon as a contract is signed. At least then we know before the installation date whether an upgrade will be required.

 

[h2ofun]

How often does this happen? Is there anyway to confirm that the transformers can handle the new solar equipment?

I’m installing mine in two weeks. Tesla wants full payment after city inspection but before PTO. If the transformer cost needs to be paid by the homeowner then it drastically changes whether or not solar is financially worth it. I’m trying to get Tesla to submit the paperwork for PTO prior to install but haven’t had any luck there either.

From what I have seen, companies do not send in for PTO until county has inspected and you have paid 95% of the contract.

 

[Vines]

From what I have seen, companies do not send in for PTO until county has inspected and you have paid 95% of the contract.

Many companies do not want to torpedo their own jobs. Many less affluent customers will back out if there is an upgrade required. Asking for PTO afterwards is a strategy for them to make sure that is your problem after you pay them for the work.

 

[h2ofun]

Many companies do not want to torpedo their own jobs. Many less affluent customers will back out if there is an upgrade required. Asking for PTO afterwards is a strategy for them to make sure that is your problem after you pay them for the work.

It seems to make no sense to ask for PTO, until all the other inspections have happened and everything passes code and is ready to go?
Now, I do know when I did my last set of solar panels, I had zero idea if PGE would approve. I was told that if they did not, the installer would have to take everything off at their cost? I have heard of a few cases this happened. You have any experience like this?

 

[Vines]

It seems to make no sense to ask for PTO, until all the other inspections have happened and everything passes code and is ready to go?
Now, I do know when I did my last set of solar panels, I had zero idea if PGE would approve. I was told that if they did not, the installer would have to take everything off at their cost? I have heard of a few cases this happened. You have any experience like this?

If it doesn't pass code, the installer should have known that ahead of time, no excuse and they better fix it. That sounds like just how they sell you on the idea of asking for PTO after installation.

I have no idea how another company would deal with this, I think it's silly to find out after the installation is done. Probably they do come to remove your entire system, or some portion of it if you still owe them money for it.

 

[mjwojtukiewicz]

I purchased my Tesla Solar energy system last year, and since then have been shouting from the rooftop about how much I love the system and appreciate the energy independence, convenience, and energy security.

There are now 4 houses in my court that have solar energy systems and three more who are actively asking me questions in preparations for also going solar.

The other day, one of those neighbors approached me saying PG&E informed him that because there was an upper limit to how much electricity could be sent to the grid given our current electrical infrastructure (I'm assuming the physical makeup of the equipment that feeds our particular court electricity) and if more solar was installed in our court, they would either artificial restrict how much power each house could send back to the grid, or simply prevent any more solar from being installed at all!

I'm not certain if this is just a ploy by PG&E to further discourage rooftop solar, or if there is validity in this warning, because I can tell you, that if they just arbitrarily restrict the energy I can send back, I'm going to be VERY upset.

Has anyone else ever encountered anything even remotely like this? Because it is literally the first time I've ever heard of it...

My neighbor mentioned they said something about transformer capacity. I'll try to get more details. Our electrical delivery equipment is not ancient either. It is undergrounded and the boxes at the end of the street are very new; I'd say 8-10 years old?

Guy who came around last year said if the power company (in my case PSEG Long Island) determined there was too much solar in a certain area they could deny the permit

 

[1100MCM]

Not a ploy from PG&E. Before the advent of EV chargers and solar it was common to put 10 houses with 200 A service on a single 50 kVA transformer. On a cool spring day, the solar fed back to the grid can overload the neighborhood transformer so they try to limit the amount of solar on a particular transformer. Now on new subdivisions they’re putting half of the amount of houses on a transformer to make room for EV chargers at night and solar backfeeding to the grid on low demand days (i.e. cool spring afternoons). On existing subdivisions they limit the amount of solar or negotiate some kind of arrangement to replace the transformer. Batteries help little in this situation since they’ll fully charge and have to feed the excess to the grid. I’m unsure if Powerwall can restrict solar backfeed by turning it off when batteries are full.

 

[jjrandorin]

I’m unsure if Powerwall can restrict solar backfeed by turning it off when batteries are full.

I am pretty sure it can, for places that do not allow backfeeding the grid (I am thinking installs in hawaii or something where they are not allowing new net metering from what I remember reading). I also think in newer installs, how they do the "pre pto" setup where solar is curtailed based on house load / batteries, this confirms its possible.

I dont think its a "normal" configuration for most places however, and in situations where there are no batteries, that obviously wouldnt be possible.

 

[CrazyRabbit]

That is why you want to be the first person to install solar on you transformer. You snooze you lose!

 

[h2ofun]

That is why you want to be the first person to install solar on you transformer. You snooze you lose!

I am the only person with solar on my transformer I believe. And at 30kw, I am just waiting to hear if anyone else wants to install, that there is no capacity left.

 

[pl804]

It is certainly a thing that the utility can limit the solar backfeed if it will risk equipment.

My understanding is this: in PG&E territory if a transformer upgrade is required on a shared transformer, I believe PGE pays for it 100% or 95% at least.

If the transformer is dedicated to your property, then the cost of the upgrade is yours to bear, and PGE might take on a nominal sum.

In CPAU territory it is much worse, but at least there they only ask that you pay the actual equipment cost, and CPAU will pickup most or all of the labor, I think. CPAU only allows less than 20 kW of combined PV+PW to be installed before the transformer likely needs an upgrade.
Palo Alto's climate goals threatened by inadequate power grid

How much does a transformer upgrade run in Palo Alto? Tesla told me I’d have to pay for one if we got more than 1 PW, but didn’t say how much it would cost.

 

[Vines]

How much does a transformer upgrade run in Palo Alto? Tesla told me I’d have to pay for one if we got more than 1 PW, but didn’t say how much it would cost.

Not something I can quantify sorry. I believe its "less" than it would cost in PGE territory but I cannot quantify that further from my limited experience with CPA upgrades.

 

[charlesj]

How much does a transformer upgrade run in Palo Alto? Tesla told me I’d have to pay for one if we got more than 1 PW, but didn’t say how much it would cost.

I would call the power company directly where you are how much $$ and if the existing transformer serves other homes as well why cannot power company pay for it or split it among all the served.
Not sure what the federal law is on this and may be of interest to find out if power company can restrict you like this.

 

[bruce4000]

I was talking to a friend of mine who works for a Utility planning for future grid upgrades. So yes there can be problems with too much solar feeding back at the neighborhood level but also as more solar comes on line at the wider grid level.
Most people just think about can enough power be supplied but he says a bigger problem will be in many regions during Spring and Fall when demand is low (little heating and cooling). This is because at every second of every hour of everyday of the year, the Utility has to control the Voltage and Frequency of the grid to tight limits. Normally it does this by balancing Utility generation to match the demand. But if there is low demand and Consumer solar is generating a significant amount that the Utility has no means to control, then the Voltage and frequency will go out of limits.
So he says that as battery prices come down, rooftop solar needs to also install batteries to match the houses generation and use to limit how much going to Grid.
Also Utilities will need to start adding grid scale storage like Tesla Megapcks.