Noob questions....

[ethonbridges]

A couple of burning questions before I decide whether I want to get serious about solar...keep in mind I have only had stuff thrown at me thus far, don't know if it's true or not, that's why I'm here, to get the straight poop.

1. If you do not intend to sell electricity back to the utility, is net metering required at all?
2. Do inverters these days shutdown if the grid is down? If so, is there still a requirement that there be a power company accessible shutoff on the outside of the building?

[Salts]

Solar systems come in 2.5 flavors. 1) Grid Tie, 2) Off Grid 3) Hybrid (grid tie with battery backup).
If you're grid tie or hybrid, you need a net metering contract.. if you're off grid, you don't.

Grid tied inverters are required by law to shut down when the grid is down. This is so a lineman working to repair the line doesn't get electrocuted.

That said, its not quite as simple as that. There are off-grid battery inverters that can turn a Grid Tied solar system into an Off Grid system using a technique called AC Coupling. These types of inverters are normally quite expensive and are what is known as the "Hybrid" system.

Mine is a hybrid. I'm normally grid tied and sending power back to the power company, but when a storm rolls through and we lose power, my system turns into an off-grid system and still provides full power to the house. Hybrids and Off Grid systems require batteries, grid tied systems do not. Hybrids and Off Grid systems keep going when the grid is down, pure grid tied systems turn off.. with one exception. Some Grid Tied inverters, like the Sunny Boy series, have what is called "Secure Power Supply" or SPS. If the grid is down and the sun is shining, they can provide a limited amount of power to an emergency circuit like a sump pump or so you can charge your cell phone or run a fridge. They are normally only 120 volts.

Grid tied solar systems are cheap, efficient, and usually require no maintenance. Off grid systems are usually far more expensive due to the batteries, and the fact that large battery inverters designed to run entire homes are expensive.

There is still a requirement that a power shut off is located on the outside of your home for any solar system. I believe it is part of the electrical codes so fire fighters don't get killed.

[J.P.M.]

1.) If you mean no interaction with the grid rather than simply no net excess generation, theoretically no, but unless you have an off grid lifestyle and know what goes with it, being a residential grid tied NEM customer of a POCO is usually a more practical situation.

Know what you're getting into if you plan to pull the plug on the POCO. Most have no clue what's required.

If you mean you don't want to have net excess generation over a period of time, say a month or a year, size the system accordingly and manage your loads for each billing period and go with a grid tied system.

2.) Yes.

As one suggestion of a way to help with your burning questions, get ahold of a copy of "Solar Power Your Home for Dummies", a free PDF download, or ~ $25 or so for an updated hardcopy version @ bookstores/Amazon/etc.

[bob-n]

Salts and J.P.M. are correct, as always.

I've heard that you can feed power back into the grid without netmetering and without power company approval, but you won't get paid for the electricity. You might actually get charged extra for the energy you supply, because old-fashioned power meters don't know whether the power is coming or going. I've never seen it confirmed in writing that backfeeding without approval is allowed. Your power company may prohibit it, but in practice, they'd never know.

Each power company has different restrictions. Before you get too far along, go to your power company's website to learn their restrictions. You might also check with your local city or town building department. They may have additional requirements.

The concept you describe where the inverters shutdown when the grid goes down is called "Rapid Shutdown". Some inverters required an extra device or devices to implement rapid shutdown. But with time, it is getting built in to more and more inverters, because it is required by code.

All of these requirements are in the name of safety. It's baffling why so many different interpretations of "safe" exist. But that's another subject.

[Ampster]

...

1. If you do not intend to sell electricity back to the utility, is net metering required at all?
.....

I don't think the other posters addressed this but there are some grid tie inverters that can be programmed for zero export. In that case it is my belief that only a building permit is required. My belief is based on California rules with the Investor Owned Utilities and may not apply to municipal or other providers or in you jurisdiction. You need to verify what the rules are for your jurisdiction.
The only way that would make sense economically is if the net metering rules with your power provider are not beneficial and much of your consumption is during the same times that solar production is meaningful.

[bcroe]

A couple of burning questions before I decide whether I want to get serious about solar..

1. If you do not intend to sell electricity back to the utility, is net metering required at all?

Before going into serious solar, I did study what could be achieved by solar
without a 2 way net metering setup. My conclusion was that it would be a
HUGE WASTE of the energy potential of the panels. The availability of
energy just never matched up with the loads. Now on net metering for 7
years, no energy potential generation wasted. Bruce Roe

[Ampster]

.............

I've heard that you can feed power back into the grid without netmetering and without power company approval, but you won't get paid for the electricity. You might actually get charged extra for the energy you supply, because old-fashioned power meters don't know whether the power is coming or going. I've never seen it confirmed in writing that backfeeding without approval is allowed. Your power company may prohibit it, but in practice, they'd never know.........

There was a recent thread on this forum where the poster lived in Big Bear and his utility did not have net metering but he installed a system that was supposed to be non export/ However the installer configured it wrong and it exported and his local utility did charge him for the power that he exported.

As far as the utility never knowing, I know of two examples in which friends had solar installed and someone left the circuit breaker on for a while before the PTO was received. That is not legal but in one case the installation had been inspected and approved by the local building authority. Nevertheless my friends and I observed the meters counting the export and presumably that information was uploaded by that smart to the power companies but nothing was ever reported to the homeowner. One of those examples was SCE and the other was PGE. I don't condone any of that and am pointing it out because at least for those utilities I know that they have the tools to find out if you are exporting power. I do know that neither of my friends bills were affected by the power that they gave to the utility.

[bob-n]

Ampster: You said "That is not legal" about powering the grid before PTO was received. Can you please help me find documentation on what regulation is violated or where it is written that this is not permitted? I'm not disagreeing with you, but haven't yet seen it in writing and I'm talking with people who say it is perfectly acceptable. Thank you.

[Ampster]

Oddly it is in the Labor Code for some reason in California: (a simple Google search)
"No electrical power source, permanent or temporary, shall be connected to a premises wiring system, or parts of such a system, unless positive means are used to prevent the transmission of electricity beyond the premises wiring system, or beyond any intentionally segregated parts of such system. "

https://www.dir.ca.gov/title8/2320_9.html

Notice it says "beyond the premises wiring system". What that means to me is somewhere between a service panel and the meter. I have often maintained that in California, the Investor Owned Utilites have not authority behind the meter. That is an important distinction for the purposes of installing any equipment that can generate or convert energy. My hybrid inverter, for example is not subject to their jurisdiction as long as it does not export. I do need a building permit for that or any electrical circuits that I add.
I hope that helps to clarify.

To be clear, a GT inverter that is set for non export would, in my opinion, not violate the law. Note, I am not a lawyer and not expressing a legal opinion. No one should rely on any opinion on the Internet without verifying the information.

[SunEagle]

Oddly it is in the Labor Code for some reason in California: (a simple Google search)
"No electrical power source, permanent or temporary, shall be connected to a premises wiring system, or parts of such a system, unless positive means are used to prevent the transmission of electricity beyond the premises wiring system, or beyond any intentionally segregated parts of such system. "

https://www.dir.ca.gov/title8/2320_9.html

Notice it says "beyond the premises wiring system". What that means to me is somewhere between a service panel and the meter. I have often maintained that in California, the Investor Owned Utilites have not authority behind the meter. That is an important distinction for the purposes of installing any equipment that can generate or convert energy. My hybrid inverter, for example is not subject to their jurisdiction as long as it does not export. I do need a building permit for that or any electrical circuits that I add.
I hope that helps to clarify.

To be clear, a GT inverter that is set for non export would, in my opinion, not violate the law. Note, I am not a lawyer and not expressing a legal opinion. No one should rely on any opinion on the Internet without verifying the information.

I agree that it still comes down to what the local electrical code and POCO feels is acceptable for a grid tie system.

They own the grid so what they say goes no matter how crazy it may sound to the home owner.