PG&E EPSS and generator options

[wwu123]

TIL via an e-mail from PG&E that there is such an area called Enhanced Powerline Safety Settings (EPSS), and that I live in one. These are adjacent to PSPS high fire risk areas, which I'm not in but close to within a half-mile. By the rough EPSS map for Santa Clara County, I'm just inside the edge of the EPSS area. These areas will shut off the power more quickly during fire season if say a branch drops on a powerline (common occurrence in our neighborhood).

Anyways, the larger point of the e-mail is that I qualify for a $300 generator rebate since I'm in a PSPS or EPSS area. What's even more interesting though, is leaning about EPSS, it seems there is also a different offer of a free Backup Power Transfer Meter (BPTM) and installation for PSPS/EPSS customers, if you own a qualified generator. It is a raised ring that goes into the meter socket behind the actual meter - similar to the Tesla Backup Switch (for Powerwalls, but not approved by all AHJ's). The BPTM has a 240V 14-30 connector, so you can plug in a generator directly behind the meter to power your entire home panel - so no fuss of having to install your own generator lockout/transfer switch, or moving circuits to a backup panel.

Anyone here have experience with this? Obviously not the folks with Powerwalls, but how about the solar-only folks here? Seems like a good deal to enable a whole-home backup option with no fuss. There's at least one sub-$500 dual-fuel genny on the list I see already, maybe worth buying just to get the BPTM installed for free, and then instead buying an EcoFlow or other battery generator to provide backup power instead....

 

[BGbreeder]

Yes, I looked into this, and the issue for me was that for the way things are wired here (whole house backup), the meter backup generator switch feeds power into the gateway and powerwalls before feeding the house that would appear on the face of it not to be a Tesla supported use of generator power.

So, I'm looking at a transfer switch to isolate the gateway and Powerwall from any generator power.

I have come to realize that for long storms, or extended wildfires, or say earthquakes, we still need backup power from a generator.

All the best,

BG

 

[h2ofun]

Yes, I looked into this, and the issue for me was that for the way things are wired here (whole house backup), the meter backup generator switch feeds power into the gateway and powerwalls before feeding the house that would appear on the face of it not to be a Tesla supported use of generator power.

So, I'm looking at a transfer switch to isolate the gateway and Powerwall from any generator power.

I have come to realize that for long storms, or extended wildfires, or say earthquakes, we still need backup power from a generator.

All the best,

BG

Yep, which is why I also have a 22kw propane generator for last resort. With folks having power out the last few years for like 2 weeks, and lots of clouds for no solar basically, ...

 

[jjrandorin]

(Moderator note)

Bump for the OP (thanks for moving the generator part of the discussion in the other thread over here, here is a bump to re surface this thread)

 

[wwu123]

OK, so I found the 2022 thread on the BPTM here:

PGE Transfer Switch

TL;DR on that discussion, it is NOT an OEM of the GenerLink product, it is PG&E's own custom design, same hookup behind the meter socket, but none of the app, or Automatic Start/Stop of the generator.

Also, you qualify for free install if you are in a High Fire Threat 2 or 3 area, but you DON"T have to be Medical Baseline. Perhaps new since 2022, you also qualify if you are in an EPSS area - h2ofun, that seems to include ALL of Placer and Nevada counties according to the EPSS maps.

So picking up from the Enphase thread tangent, what I've been educated on is basically the general risk of combining whole-house generator backup with solar PV - it's not at all specific to the BPTM. In researching further, the risk is a backup generator waveform causing solar PV inverters to sync and energize power back to generator - if insufficient house loads, the PV inverter will basically try to spin the generator backwards, causing potential havoc. Having batteries can mitigate this, since they can absorb excess power from PV and/or generator.

The PG&E BPTM, as far as I can tell, can automatically switch between utility and generator power, but does NOT autostart a generator. Theoretically, if one follows the stated manual procedures, then one can always disconnect the PV before the generator is on. However, there is still a human risk of leaving both connected at the same time. It seems similar to why one shouldn't just backfeed a generator to a panel through a breaker connection - theoretically it can work, but relies on the human to always throw the right switches - thus a physical interlock is better, as it physically prevents the generator breaker and the main panel breaker from being both connected at the same time.

But here's where I get a bit lost. cali8484 suggests solar inverter needs to be reconfigured from a circuit breaker connection (AFAIK the most common way to install solar) to a line-side tap. This appears to be a widely accepted way to install whole-house generator backup with PV solar - but this generally assumes the generator is wired in with a manual or automatic transfer switch downstream of the line-side tap. I.e.

utility feed -> meter socket -> solar inverter line-side tap -> generator transfer switch -> main panel -> house loads

So the solar is same side of the transfer switch as the utility feed - so the transfer switch will keep the solar inverter and generator on opposite sides of the transfer switch (specifically keeping the inverter on the utility side, so if the grid is down, the solar is always down).

But this doesn't seem to pass logic with the BPTM, because a line-side tap is downstream of the BPTM, i.e.

utility feed -> meter socket/BPTM (cannot be separated, therefore generator connects here) -> solar inverter line-side tap -> main panel -> house loads

So it only seems to work if you manually hit the disconnect on the solar inverter BEFORE starting up the generator - which is no different or better than having to manually open the circuit breaker on the solar inverter in most breaker-connected PV installs. So you're still reliant on the human following the correct procedures. There are two slightly incongruous manuals/guides for the BPTM, but the amalgam of both is essentially:

1. Turn off the main panel breaker.
2. Turn off ALL the house load breakers.
3. Disconnect the solar PV from the main panel (they always use the word disconnect or show a disconnect box, so are they specifically disqualifying breaker-connected solar inverters?)
4. Connect the generator to the BPTM, and start the generator.
5. Wait about 15 seconds for the BPTM to switch over from utility to generator.
5. Turn on ONLY the house load breakers you want to power;
6. Turn on the main panel breaker.

When the grid comes back on, the BPTM automatically disconnects the generator for 6 seconds, then reconnects the grid to the main panel. The manual is incomplete after that, but per the Chilton automotive repair manuals of yore, "assembly is the reverse of disassembly", I suppose. So basically turn off the generator, and then reconnect the solar PV.

So why would a line-side tap be any better here, if Step 3 above is both needed just the same as turning off a solar inverter breaker connection, and both are prone to human error?

 

[BGbreeder]

OK, so I found the 2022 thread on the BPTM here:

PGE Transfer Switch

TL;DR on that discussion, it is NOT an OEM of the GenerLink product, it is PG&E's own custom design, same hookup behind the meter socket, but none of the app, or Automatic Start/Stop of the generator.

Also, you qualify for free install if you are in a High Fire Threat 2 or 3 area, but you DON"T have to be Medical Baseline. Perhaps new since 2022, you also qualify if you are in an EPSS area - h2ofun, that seems to include ALL of Placer and Nevada counties according to the EPSS maps.

So picking up from the Enphase thread tangent, what I've been educated on is basically the general risk of combining whole-house generator backup with solar PV - it's not at all specific to the BPTM. In researching further, the risk is a backup generator waveform causing solar PV inverters to sync and energize power back to generator - if insufficient house loads, the PV inverter will basically try to spin the generator backwards, causing potential havoc. Having batteries can mitigate this, since they can absorb excess power from PV and/or generator.

The PG&E BPTM, as far as I can tell, can automatically switch between utility and generator power, but does NOT autostart a generator. Theoretically, if one follows the stated manual procedures, then one can always disconnect the PV before the generator is on. However, there is still a human risk of leaving both connected at the same time. It seems similar to why one shouldn't just backfeed a generator to a panel through a breaker connection - theoretically it can work, but relies on the human to always throw the right switches - thus a physical interlock is better, as it physically prevents the generator breaker and the main panel breaker from being both connected at the same time.

But here's where I get a bit lost. cali8484 suggests solar inverter needs to be reconfigured from a circuit breaker connection (AFAIK the most common way to install solar) to a line-side tap. This appears to be a widely accepted way to install whole-house generator backup with PV solar - but this generally assumes the generator is wired in with a manual or automatic transfer switch downstream of the line-side tap. I.e.

utility feed -> meter socket -> solar inverter line-side tap -> generator transfer switch -> main panel -> house loads

So the solar is same side of the transfer switch as the utility feed - so the transfer switch will keep the solar inverter and generator on opposite sides of the transfer switch (specifically keeping the inverter on the utility side, so if the grid is down, the solar is always down).

But this doesn't seem to pass logic with the BPTM, because a line-side tap is downstream of the BPTM, i.e.

utility feed -> meter socket/BPTM (cannot be separated, therefore generator connects here) -> solar inverter line-side tap -> main panel -> house loads

So it only seems to work if you manually hit the disconnect on the solar inverter BEFORE starting up the generator - which is no different or better than having to manually open the circuit breaker on the solar inverter in most breaker-connected PV installs. So you're still reliant on the human following the correct procedures. There are two slightly incongruous manuals/guides for the BPTM, but the amalgam of both is essentially:

1. Turn off the main panel breaker.
2. Turn off ALL the house load breakers.
3. Disconnect the solar PV from the main panel (they always use the word disconnect or show a disconnect box, so are they specifically disqualifying breaker-connected solar inverters?)
4. Connect the generator to the BPTM, and start the generator.
5. Wait about 15 seconds for the BPTM to switch over from utility to generator.
5. Turn on ONLY the house load breakers you want to power;
6. Turn on the main panel breaker.

When the grid comes back on, the BPTM automatically disconnects the generator for 6 seconds, then reconnects the grid to the main panel. The manual is incomplete after that, but per the Chilton automotive repair manuals of yore, "assembly is the reverse of disassembly", I suppose. So basically turn off the generator, and then reconnect the solar PV.

So why would a line-side tap be any better here, if Step 3 above is both needed just the same as turning off a solar inverter breaker connection, and both are prone to human error?

Mostly, it is a wiring issue. If the home wiring has the solar/gateway/powerwalls on "T", where you can easily shut them off, great. However, because the BPTM injects generator power at what is normally the grid entry point, most people will need to go around and throw the appropriate (solar/gateway/Powerwall) breakers. (Side note: if the wiring in the gateway doesn't land the solar / powerwalls there, you will lose the ability to have solar recharge your powerwalls while the generator powers the house.) Transfer switch may be able to isolate the solar/gateway/powerwalls for you, but it depends on your particular wiring.

And now back to our regularly scheduled program...

All the best,

BG

 

[shs1]

I am in PG&E territory and several years ago managed to integrate an existing 18 kW generator into a solar/Powerwall 2 installation. I started this thread on the process which frankly Tesla made difficult at the time.

PowerWall 2 Interface with a Generator

We have a grid-tied all electric home plus an MS, and hopefully soon a 3, powered by 11.4 kW of solar PV, and during power failures, a Kohler 18 kW propane generator. In the next few days we be getting a PW2, and likely soon thereafter, a 2nd one. The question is how the PW2 gateway...

teslamotorsclub.com

I currently have 3 Powerwalls and during the summer I can go virtually forever during a power failure running on the solar (11 kW) and my now 3 Powerwalls. But in the winter with snow and more limited sun, I need the generator as our all electric house need electricity for heat (geothermal heat pump) and very glad I have it. This last winter we were without grid power for most of 2 weeks and had more than 10 feet of snow which made my solar output nil.

In my setup (see pic) I can either allow the generator to automatically come on if the Powerwalls fail, or almost always I manage my generator use and manually select the generator during time of high anticipated use and use the Powerwall to run when the demand is less.

 

[wwu123]

Thanks to both of you for your replies!

I was for a bit wondering if maybe a typical generator interlock kit might be usable if you put the solar breaker on it, but quickly realized that wouldn't work, because those are trying to lock out the main breaker - the main breaker has to be on for the BPTM to work.

But like shs1's design, one could install a transfer switch, with the solar and generator on opposite sides. I think it should be easy enough to move the solar from its circuit breaker in the main panel to a transfer switch.

I think for the infrequent 1-2X/year I really need the generator though, I think I can get by remembering to manual flipping the solar breaker - since I have to hook up the 14-30 cable to the BPTM at the panel anyways, so would make sure to run through the checklist including the thorough guidelines flip off the main breaker until the BPTM has switch over to the generator.

Just waiting now to see if PG&E can reply to confirm that I'm actually in the EPSS area, my street is right under the thick line that designates the border of the EPSS zone, so I'm not 100% sure I'm actually eligible despite their "pre-qualified" e-mail...

 

[wwu123]

PG&E finally responded to my e-mail after about a week:

Good News - They confirmed I am on an EPSS circuit, and eligible for the $300 generator rebate.
Bad News - The BPTM program is currently closed to new applications due to "overwhelming demand" (even though it appears to be only a year old program). They said to check back later in 2023...

 

[greendublin]

PG&E finally responded to my e-mail after about a week:

Good News - They confirmed I am on an EPSS circuit, and eligible for the $300 generator rebate.
Bad News - The BPTM program is currently closed to new applications due to "overwhelming demand" (even though it appears to be only a year old program). They said to check back later in 2023...

Interesting. My application must have got in just before this arbitrary cutoff. I applied in late February and was informed that I am on the deployment list, but no estimated timeline. Hope they install it soon as some of the neighborhoods around me in East Bay have already experienced power outage over the past few weeks.

 

[wwu123]

Interesting. My application must have got in just before this arbitrary cutoff. I applied in late February and was informed that I am on the deployment list, but no estimated timeline. Hope they install it soon as some of the neighborhoods around me in East Bay have already experienced power outage over the past few weeks.

The person who confirmed I was in EPSS and eligible also e-mailed a request/waiver program form, suggested there was a long backlog. But at least I think they added me to the back of the line. They seem to have opened it back up publicly, as there is now a request link at the bottom of the PG&E webpage again (albeit it just addresses an e-mail to the program alias, but it is the same e-mail that the generator program folks pointed me to....

Hard to tell how quickly they're processing the queue, but I'm hoping it'll be by winter storm season...

 

[cwerdna]

'This is hell’: Repeat outages mar PG&E’s wildfire safety shift from tree trimming to circuit breakers ​

“There has to be a better solution.”

https://www.mercurynews.com/2023/08...shift-from-tree-trimming-to-circuit-breakers/

See https://archive.is/wDHGN if you get hit by a paywall.

Yes, my area is part of "Enhanced Powerline Safety Settings or EPSS" or at least we get hit by them. There is no wildfire danger anywhere near me w/any of the above ground power lines, however, I suspect some lines further away that do feed us are.

As I've posted elsewhere, in 2022, I had at least 13 power outages at home not including brief glitches. And, I had at least 11 in 2021, not including brief glitches.

 

[wwu123]

The person who confirmed I was in EPSS and eligible also e-mailed a request/waiver program form, suggested there was a long backlog. But at least I think they added me to the back of the line. They seem to have opened it back up publicly, as there is now a request link at the bottom of the PG&E webpage again (albeit it just addresses an e-mail to the program alias, but it is the same e-mail that the generator program folks pointed me to....

Hard to tell how quickly they're processing the queue, but I'm hoping it'll be by winter storm season...

So following up the thread that PG&E showed up suddenly today Saturday to install the BPTM, no advanced notice, but given it took only about 10 minutes with power off, it was fine. He spent more time explaining the proper procedures and answering some of my questions than it took to install it.

Total backlog time from when I signed up in April was five months, not too bad as long as it was before the winter storm season. We've not had any EPSS-related shutdowns in my area that I'm aware (I feel for you guys in the East Bay), just a few of the normal brief summer outage blips. I noticed they shut down the sign-up page as of last month, for the rest of 2023 - it appeared to be reopened for at least a few weeks around July/August, so anyone in queue they should get to eventually.

Anyways, as he explained, there is absolute no way to test the BPTM, it can only switch to generator when grid is down. Since this is on the line side of the meter, can't simulate outage by flipping any breakers or shutoffs on the home side. I trust it will work though.

My bigger decision now is choosing the right 240V generator ( I was going to order as soon as I got notice they were coming, fortunately they didn't care to see my generator). The big uncertainty I have is whether it matters if it's a floating neutral vs bonded neutral - I see both types on PG&E's compatibility list without any caveats. My understanding is when using a whole-house transfer switch, since the home panel is already bonded neutral-to-ground, one should not have a bonded neutral at the general (should be floating neutral generator). The BPTM seems similar even though it's on the upstream side of the main panel - PG&E doesn't warn about bonded-neutral generators though.

I asked the PG&E tech, he said he has a generator interlock switch on his home's panel, but he only answered about grounding the generator, saying it was unnecessary since the home panel was already grounded. He seemed to suggest if the generator wasn't separately grounded, then it was fine as neutral would only go to ground at the panel - but he didn't really address or seem aware of any issues of having neutral tied to ground at two different locations (creating a loop). My home panel is filled with GFCI and AFCI breakers, so not sure if they will function properly with bonded-neutral generator.

Anyways, if I order a bonded-neutral generator, I've read you can open it up and disconnect the bonded-neutral connection - I hope that would be always true...

 

[cali8484]

Better get a floating neutral generator. It's easier to bond using a bonding plug if needed then unbond a bonded neutral generator. Too bad you can't test or manually switch BPTM.

 

[RKCRLR]

My generator came set up for bonded neutral but had instructions on how to make it floating neutral. I converted it to floating neutral for use as a backup generator and use a bonding plug when I want to use it as a portable generator.

 

[wwu123]

My generator came set up for bonded neutral but had instructions on how to make it floating neutral. I converted it to floating neutral for use as a backup generator and use a bonding plug when I want to use it as a portable generator.

So quick Q to everyone on this - I see in the wiring diagram for the model I want to buy, that it is "bonded neutral". The white neutral wire is diagrammed as tied to "ground" (I assume meaning the metal frame), the diagram also shows from there also tied to the grounding nut, where ground wire must also be tied to the frame. So I should be able to detach the white neutral wire where they'll it connected to frame to float it, and then do what you do I assume.

But wondering about the GFCI in the 120V outlets on this generator - will they work OK in both scenarios (backup vs portable)? If the genny came with neutral tied to ground on the back side of the outlet, and I'm connecting them with a bonding plug on the front side of the GFCI, those should look the same to the GFCI? If I happen to leave out the grounding plug after doing the mod, will the GFCI freak out if it finds no proper connection between neutral and ground? I believe GFCI's look for a mismatch in current between the hot and neutral - when neutral is tied to ground, is it typical for some return current to be going via the plug's ground pin, which again is bonded to the neutral via the frame, which would trip the GFCI?

Reason this is somewhat important, is the side of the house where I need to store the generator is steeply sloped with a narrow dirt path (that will further be slippery and muddy during the winter months typically). I'll need to wheel the generator about 50 feet down this narrow path (8 ft elevation drop), avoiding it slipping sideways (down a 50 foot hill), to get close enough to the BPTM/meter (comes with a special 20' 14-30 cable). Therefore I'm looking for the lightest, smallest 240V I can find - and there is one that is significantly lighter and narrower (15 lbs and 6" respectively) than the rest, from a decent enough brand. It's <5000W, but my only big 240V loads are the oven and the EV charger, neither of which will be used during a power outage - plus the BPTM is only 30A, so can't feed more than 7200W anyways.

 

[BGbreeder]

GFCI devices electronically compare the hot current to the neutral current, and if the difference is more than a set amount, they interrupt the circuit. In a sense they "don't care" where the extra hot current goes, just that it isn't returning on "their" neutral.

Everything to Know About GFCI Receptacles

Master electrician Heath Eastman teaches host Kevin O’Connor everything he needs to know about ground fault circuit interrupters.

www.thisoldhouse.com

The actual trip current difference, depends on the class of GFCI, (A, B, C, D, & E). Class A devices trip at a current leakage of 5mA or more. Most of the other classes trip at 20mA, but you are unlikely to trip across any variety other than Class A, B, or C (less than 300V operation).

GFCI Class A, B, C, D, E Meaning (With Its Trip Level)

It is not that difficult to understand why the NEC encourages consumers to use GFCIs. According to the Home Electrical Fires, electrical issues cause over 50,000 fires annually, killing hundreds of people and injuring thousands.

portablepowerguides.com

My personal concern about portable generator grounding and bonding is about failure modes. Since generators tend to get moved around, and their cords get moved around, there is more of a potential for things that were ok to become unsafe. There have been extensive discussions on what is "correct" and why. My $0.02 is to always assume that there are fatal levels of power on a generator frame, and plan your actions accordingly. On the subject of free advice, my other generator tip are never, ever, refill a running generator, and don't run one in the rain or inside a closed space.

YMMV!

All the best,

Peter

 

[wwu123]

My personal concern about portable generator grounding and bonding is about failure modes. Since generators tend to get moved around, and their cords get moved around, there is more of a potential for things that were ok to become unsafe. There have been extensive discussions on what is "correct" and why. My $0.02 is to always assume that there are fatal levels of power on a generator frame, and plan your actions accordingly. On the subject of free advice, my other generator tip are never, ever, refill a running generator, and don't run one in the rain or inside a closed space.

YMMV!

All the best,

Peter

Thanks, seems like sage advice, esp since the most likely scenarios for me are winter storms where the ground will be wet, I'll be wet, the generator frame unfortunately will be wet, so try to avoid touching the generator with bare hands and becoming the easier path to ground.

I guess in some sense the GFCI would be a good canary to warn that some current is leaking via the (likely wet) frame, and trip at smaller currents to warn me. OTOH, I realized if I'm only using it in the intended 240V house backup scenario, the 120V GFCI on this unit won't ever be powered at all, nor would I need it (since all my home 120V outlets would be available).

My other option would be to get a 50' 14-30 extension cord, so I could both store and run the generator from under a tall deck. In that case I could get a heavier/larger generator, it would be just a one-time move to get it permanently in place. Though I would be running 240V through 70' of (wet) cable lying on the (wet) dirt - (theoretically up to 7200W, but really most of the time 500-2000W). Do you feel that would be safer/preferable?

 

[cali8484]

It's better to get an extension cord or even better would be a permanently installed one. The extension should be over sized to avoid too much voltage drop. It doesn't seem practical to wheel a generator out with the long distance and steep environment you have. Think when it's dark and raining.

 

[BGbreeder]

Thanks, seems like sage advice, esp since the most likely scenarios for me are winter storms where the ground will be wet, I'll be wet, the generator frame unfortunately will be wet, so try to avoid touching the generator with bare hands and becoming the easier path to ground.

I guess in some sense the GFCI would be a good canary to warn that some current is leaking via the (likely wet) frame, and trip at smaller currents to warn me. OTOH, I realized if I'm only using it in the intended 240V house backup scenario, the 120V GFCI on this unit won't ever be powered at all, nor would I need it (since all my home 120V outlets would be available).

My other option would be to get a 50' 14-30 extension cord, so I could both store and run the generator from under a tall deck. In that case I could get a heavier/larger generator, it would be just a one-time move to get it permanently in place. Though I would be running 240V through 70' of (wet) cable lying on the (wet) dirt - (theoretically up to 7200W, but really most of the time 500-2000W). Do you feel that would be safer/preferable?

I applaud your efforts to increase your resiliency.

Just to be clear, GFCI devices will only protect things plugged into the GFCI outlet. The high power generator outlet is not usually protected, at least in most of the consumer generators that I have seen, and the high power outlet is probably what your backup meter plugs into.

I would recommend that you either find a dry location to run your generator from, or at least a three sided pop tent (Well staked down...). Water and portable generators are not generally good or safe bedfellows...

I would check the wire gauge on your cords; as @cali8484 suggests, oversized is better as it reduces power losses and voltage drops.

I would not worry about a generator cable lying around in wet conditions, as most generator cables are at least rated SOOW, or better. (SOOW = Service, Oil, Oil, Water, meaning it is rated for being a cord that is dragged around (Service), the inner and outer insulations are rated as Oil resistant, and the whole assembly is rated for use in weather and Wet conditions) I would be careful about the plugs being dry and staying dry, as most consumer plugs / outlets do not have much water resistance. If you do put the generator someplace fixed, there might the possibility of running fixed wiring for at least some of the distance, if that helps. I would store the cable someplace dry, out of the sun, and away from rodents.

Don't forget to run your generator before you need it, let it warm up before bringing it online and change the oil at least annually; some generators suggest fairly short oil change intervals due to the engines running warm, at high throttle, and with small oil sumps. I would also think about how you are going to store your fuel, how you are going to manage the stability (age, oxidation, and turnover/replacement), and critically how much you might need to cover your idea of an extended outage. Given that we are in earthquake country, I tend to plan for much longer, on the idea that even a small earthquake has the potential to disrupt many things like power, movement (to get more fuel), and indeed resupply of gas stations that may not be operative without power...

All the best,

BG