Plug in solar- legal in US?

[T3slaOwner]

I am not saying that an appliance requires a permit. I am saying that a solarpanel on a roof may require a permit and further compliance with Rapid shut Down requirements. It depends on the jurisdiction. If you put the panel on a patio cover it may not require a permit or RSD.

That's what I'm trying to understand. You are saying that it's not an electrical code thing because the solar panel plugs in an outlet. But somehow it becomes a building code issue because it is mounted to the house? Is that true for an attic fan installed that plugs into an outlet? It is bolted to the roof but plugged in like any other fan in your house, so you end up needing a permit?

 

[T3slaOwner]

One good reason that mounting solar panels on a roof requires a permit is that you have to verify structural loading. Mounting a non-trivial number of solar panels on a roof adds a significant load to be supported by the roof structure.

If you goal is to stick it to the utility, there are many solutions available that don't require utility approval because they are designed to never feed back into the grid. However, if you connect into your home electrical system, it requires a building permit in most jurisdictions. The most common of these systems is basically to set up a off-grid system with a hybrid inverter and a battery bank with the solar directly charging the batteries. Your house is powered from this system and the grid is only used to charge the batteries when they are low. It is commonly called a grid assisted system. Since the grid is only connected to a battery charger, it is impossible for the battery energy (and therefore solar energy) to flow back into the grid.

If I had clear view of the sky from my roof I would consider a small solar installation like that. I'm on TOU service which they won't allow me to combine with the net metering. I guess they are worried I'll get too good a deal pumping electricity to them at nearly $0.40 a kWh in the late afternoons. That reminds me, this is October so the hour change from summer hours of 3 to 7pm to winter hours of 6 to 9am and 5 to 8pm. Need to change settings in some timers.

EVs may help with the carbon issue, but using less electricity and especially less peak electricity nearly always produces less carbon.

 

[T3slaOwner]

The product does include a "Solar Regulator." It senses whether the power is out and if the unit is plugged in at all. While the website does not specifically answer the question about overloading a circuit, it does seem that the Solar Regulator is not dumb. Perhaps it can sense when there is more than 15 amps on the 6-15 circuit and and reduce/eliminate output.

I'm pretty sure that unless something is installed in the circuit breaker panel, or in this branch line entering the panel, there is no practical way to sense the current in the wire.

On the other hand, the only way to have an overload in the wire is if the solar panel were plugged into an outlet that is between all the other loads and the circuit panel. Any loads that are between the outlet with the solar panel and the circuit panel will get their current from the circuit panel and not contribute to the sum current by the solar panel. Put the solar panel outlet at the end of the line and you will never have an overload because of the line sharing.

 

[mswlogo]

Is something like this legal in the US?

Legion Solar 4 - Permission Free Energy and Storage

they make the statement that it is OK because they measure & throttle generation to eliminate any power going back on the grid. Therefore, they claim it isn’t grid tied.

they also provide some guideline for circuit to plug into. But, of course, disclaim any responsibility. Not reviewed for code, etc.

My assumption is not legal, but if it is illegal, what statute makes it illegal?

Keep in mind that system is only 300W. Which is typically on the lower end of what one Panel puts out today on a typical solar system.

That's a charge rate of about 1 mile per hour.

 

[Ampster]

That's what I'm trying to understand. You are saying that it's not an electrical code thing because the solar panel plugs in an outlet. But somehow it becomes a building code issue because it is mounted to the house? Is that true for an attic fan installed that plugs into an outlet? It is bolted to the roof but plugged in like any other fan in your house, so you end up needing a permit?

I am trying to give you a 10,000 foot view of the context and reasoning behind the National Electrical Code. You will have to check with your local building officials to see which version of the NEC they have adopted and if they have added any additional provisions. Just runing an extension cord through a wall or through a vent may be prohited. That would not apply to a building fan it it plugged into a receptacle in the attic, If you added a receptacle it may require a pemit and it may be required to be a GFCI receptacle. It depends and it varies across the country. Solar panels on a roof can present risks to firemen when putting out a fire. That is why the latest NEC code has a provision about Rapid Shut Down devices. The other important issue is whether this device is Underwriter Labs approved and how that might affect insurance recovery if it was shown to be a cause or a contributor to a fire in a dwelling. I don't think you will get a satisfactory answer on an online forum for the specifics.

 

[Ampster]

Put the solar panel outlet at the end of the line and you will never have an overload because of the line sharing.

That is how the physics works but there may be a rule about current generating devices needing to have their own circuit breaker that is labeled as a photovoltaic device. There are references to that in the NEC, It is not as simple as the sales brochure would like us to believe.

 

[T3slaOwner]

I am trying to give you a 10,000 foot view of the context and reasoning behind the National Electrical Code. You will have to check with your local building officials to see which version of the NEC they have adopted and if they have added any additional provisions. Just runing an extension cord through a wall or through a vent may be prohited. That would not apply to a building fan it it plugged into a receptacle in the attic, If you added a receptacle it may require a pemit and it may be required to be a GFCI receptacle. It depends and it varies across the country. Solar panels on a roof can present risks to firemen when putting out a fire. That is why the latest NEC code has a provision about Rapid Shut Down devices. The other important issue is whether this device is Underwriter Labs approved and how that might affect insurance recovery if it was shown to be a cause or a contributor to a fire in a dwelling. I don't think you will get a satisfactory answer on an online forum for the specifics.

Ok, I get it. I'm familiar enough with the code to know extension cords are not allowed for permanent installations. Otherwise they are fine used singly.

I don't know, but I would expect the "rapid shut down" to either be internal to the solar system or a separate switch easily accessible.

Otherwise I will take your advice for what you are indicating it is worth.