PV during power outage

[change_user_name]

The system is a 16-panel, 6.8kW peak with no storage from sunpower. It feeds into ConED NYC grid.
I learned that during a power outage, the system will shut down for the safety of workers at lines on the street.

If the meter would be removed during an outage, the PV would be disconnected from the grid. Would the system be functional at least during the daytime and feed the house or does it need to sense 120/240 from the grid to operate or does it need a specific load not to get damaged?

[Mike 134]

The system is a 16-panel, 6.8kW peak with no storage from sunpower. It feeds into ConED NYC grid.
I learned that during a power outage, the system will shut down for the safety of workers at lines on the street.

If the meter would be removed during an outage, the PV would be disconnected from the grid. Would the system be functional at least during the daytime and feed the house or does it need to sense 120/240 from the grid Yes needs the 120/240 to operate. to operate or does it need a specific load not to get damaged?

See response in green. How often do you have power outages that would impact your comfort or business?

[change_user_name]

Mike 134.
Outages have not been an imminent problem. Our street has not encountered a power outage since 2005, but the neighboring streets did a few times.

I am wondering if any 120/240VAC source could fake a grid to the PV. I imagine stable voltage and frequency (pure sinus) may be a requirement, type of load seen (inductive e.g.)

[ajzwilli]

Is this a newer system from SunPower? I ask because they generally use enphase micros. The IQ8 series micros (released in the last year or so) have the technology to operate when the grid is down.

[change_user_name]

I do not know the specific hardware of the system. It was installed in January 2023.

[SunEagle]

Mike 134.
Outages have not been an imminent problem. Our street has not encountered a power outage since 2005, but the neighboring streets did a few times.

I am wondering if any 120/240VAC source could fake a grid to the PV. I imagine stable voltage and frequency (pure sinus) may be a requirement, type of load seen (inductive e.g.)

So until we know exactly what type of inverter or micro inverter you are using we really can't help you except to say, no a 120/240v source is not enough to fool most grid type inverters.

What did your installer say about your system working or not if the grid is down?

[Ampster]

....

I am wondering if any 120/240VAC source could fake a grid to the PV. I imagine stable voltage and frequency (pure sinus) may be a requirement, type of load seen (inductive e.g.)

No you need a grid forming inverter with the firmware and sufficient battery capacity to act as a buffer. The process to do that is called AC coupling and the grid forming inverter has to have the software to be able to control the GT inverter system you have now. It is essentially what a Tesla Powerwall and Enphase batteries do, as well as many tier one hybrid inverters. If your sunpower system has Enphase IQ8 micros it might be able to get additional Enphase equipment installed to give you power during the day for less expense than a Powerwall, Enphase batteries or a hybrid inverter with batteries.

[Mike 134]

Mike 134.
Outages have not been an imminent problem. Our street has not encountered a power outage since 2005, but the neighboring streets did a few times.

I am wondering if any 120/240VAC source could fake a grid to the PV. I imagine stable voltage and frequency (pure sinus) may be a requirement, type of load seen (inductive e.g.)

Reason I asked about the frequency of your outages I'm guessing you, like me were disappointed we could not generate power with our fancy new system during an outage. But after looking at it logically how seldom I'd lost power it became a non-issue.

[peakbagger]

Unless in an area with frequent power outages that happen to only happen on sunny days, having the ability to generate power without batteries in the loop is IMHO just a waste of money for most people when a 6000 watt gas generator is in the $600 range. Learn how to run it out of gas and drain the carb on the rare times you use it and it should last decades. My 6000 watt generator was about $500 when I bought it 2 months after Y2K (12/1/2000) and has never been used once to actually back up my power, it has been used a few times for other purposes but starts right up if I pour gas in it. If you insist on keeping it full of fuel and ready to go (I do not recommend it for most folks), find a source of ethanol free gas (small airports or puregas.org). You can also get propane fired units if you have a bulk source of propane.

[change_user_name]

Thanks for all the suggestions. I see that the users in this forum have good knowledge.
As long as I do not know what hardware was installed I will not know if it could feed the house during the daytime without a powered grid.
Even if newer microinverters were used, feeding the grid during an outage constitutes a safety problem for workers.
I am not concerned enough to consider emergency power via a battery, generator, or millstone
I learned, in the Bronx, battery backup for PV systems is not allowed due to fire hazards and the proximity of houses. I wonder if that is only related to Lithium batteries. Lead acid batteries should be safer even if they are not the optimal choice (lower efficiency, far fewer charge cycles than Lithium Ion)

Just a brain dump: Regardless, this law could be circumvented by parking an EV in the garage to feedback using the 75++ kwH battery into the house. I am just pointing out that legislature makes less sense if you allow EV being parked near the house or in the garage unless you believe that cells in a battery backup are less safe than EV cells.

[solardreamer]

Just a brain dump: Regardless, this law could be circumvented by parking an EV in the garage to feedback using the 75++ kwH battery into the house. I am just pointing out that legislature makes less sense if you allow EV being parked near the house or in the garage unless you believe that cells in a battery backup are less safe than EV cells.

EV's are quite different from home batteries in that they are mobile and could be parked outside away from homes. Home batteries are hundred's of pounds of equipment permanently attached to building structure that first responders have no practical way of removing in a fire even when caught early.

[ajzwilli]

Even if newer microinverters were used, feeding the grid during an outage constitutes a safety problem for workers.

I learned, in the Bronx, battery backup for PV systems is not allowed due to fire hazards and the proximity of houses. I wonder if that is only related to Lithium batteries. Lead acid batteries should be safer even if they are not the optimal choice (lower efficiency, far fewer charge cycles than Lithium Ion)

No, newer microinverters with grid forming technology when installed properly (i.e. IQ8 series with the IQ Controller Smart Switch) would safely disconnect from the grid when it is running off grid.

What law are you talking about banning battery backups. You are not referring to the 5 recently passed lithium ion battery laws regarding e-bikes are you? 1 of those five laws (752) prevents the usage / sale of 2nd hand lithium ion batteries, but new lithium ion batteries are still allowed.

[PNPmacnab]

I'd say an AC source would be enough to fool it. The problem is the PV system will try to dump power into whatever that is and destroy it.

[SunEagle]

I'd say an AC source would be enough to fool it. The problem is the PV system will try to dump power into whatever that is and destroy it.

Grid tied inverters look for voltage, frequency, phase angle, and a few other parameters the grid provide along with an infinite measurement of impedance that IMO just about all temporary AC generators do not have. This makes it very hard to impersonate the grid and get an inverter to work, which is by design.

I am sorry that a lot of solar installers either forget or fail to mention that the solar inverter will stop working fully if the grid is down unless you have a highbred inverter with battery system or a limited output with a manual connection like the SMA Power Secure type.

[change_user_name]

The system installer provided us with the info that a battery backup is not allowed in our neighborhood. I did not consider batteries for various reasons. I asked anyway.
I see various restrictions from NYC and FDNY related to indoor vs. outdoor installation requiring minimum distance from structures. I am not referring to e-Bike fires in apartment buildings.
In our street houses do not have enough distance to the next house/fence/structure.

As to EV versus stationary battery:
If the vehicle is parked inside a structure (attached garage or the garage is part of the house), I see no difference in installing stationary batteries. I can not imagine that FDNY is moving a vehicle on fire.

I do not know the electrical details of the PV system that feed the grid. I agree that only these need to match: Voltage, frequency, and phase.
I consider the grid low impedance and clamping voltage system - with constant frequency and constant voltage.
The PV system can only feed current into the grid if its voltage is slightly higher at the same phase and frequency.
In theory, the PV system could function if a simple pure sine wave on the phases is sensed. It may not destroy that AC power source simulating a power grid but regulate its output power (better voltage) because the "grid" voltage would go up. Since the grid is supposed to be a constant voltage source, a control unit must prevent overvoltage.

I have no intention to test this.