How do you know? In a typical solar system, you have to have a permit, which requires an inspector to come out and ensure everything is configured correctly and safely. These don’t require any permits, which is great for making them more affordable and accessible, but there’s also no one coming around to make sure that anyone is doing it safely.
Comment on Easy-to-use solar panels are coming, but utilities are trying to delay them
eleitl@lemmy.zip 3 weeks agoThe microinverters stop feeding in if grid goes down. So it’s safe.
artyom@piefed.social 3 weeks ago
eleitl@lemmy.zip 3 weeks ago
I know it because it’s in the spec necessary for licensing. It shuts off in under 20 ms so you can’t even get shocked by the prongs of the plug if pulled out.
artyom@piefed.social 3 weeks ago
What license? Who is coming to verify your license?
eleitl@lemmy.zip 3 weeks ago
It is a commercial product, connected to the grid via a standard schuko plug, sold in Germany. It has to be compliant with the local law to be sold legally.
It all shouldn’t be so difficult to understand.
ywuduyu@piefed.social 3 weeks ago
captain_aggravated@sh.itjust.works 3 weeks ago
In the United States that would be UL Certification.
shininghero@pawb.social 3 weeks ago
Easy check, grab a voltmeter and do it yourself.
Pull the plug, set voltmeter to AC, and read the voltage across the prongs. If you get anything over the usual float voltage you get from just holding the probes ungrounded, then you have a problem.artyom@piefed.social 3 weeks ago
By “you” I did not mean your personal solar system. I mean how does the utility know that other users that have systems connected are doing so safely?
ThePantser@sh.itjust.works 3 weeks ago
The PRODUCT is designed to stop feeding OUT the plug if it doesn’t detect VOLTAGE from the socket. AC is alternating current so it pulses on and off so the solar system is doing the same. It’s turning on and off quickly and seeing if it gets power back and if it detects no power incoming it shuts off the power from the solar. It’s quite simple and ingenious.
acosmichippo@lemmy.world 3 weeks ago
you can unilaterally connect your solar panels to the grid. you have to work with the utility to turn them up, and they require permits and passed inspections.
artyom@piefed.social 3 weeks ago
According to my research, there is no such permit required in Utah. And presumably new legislation is looking to have this exception as well.
acosmichippo@lemmy.world 3 weeks ago
not true, you still need to apply to the utility to export to the grid.
Resonosity@lemmy.dbzer0.com 2 weeks ago
Inverters in the US are all listed to UL1741-SB which dictates that they shall cease to energize their AC outputs if they sense an absence of grid voltage.
Now, one thing people are ignoring is that UL1741-SB allows for islanding protection, and the disablement of it. If an inverter has its settings changed such that islanding protection is OFF, then the inverter will keep sending power to the “grid” because it thinks it’s operating on a microgrid that was previously disconnected from the larger grid via a Microgrid Interconnection Device (MID).
The settings these inverters have are user-settable, which means they need to be checked by a qualified person, either a contractor, engineer, or inspector. These settings must also often be checked by the utility you’re interconnecting to before they allow you to energize, so usually all of these parties have eyes on the inverters’ settings and can stop work before energization until things are corrected.
Ultimately I agree with you. If we don’t want to have to need inspections for every solar installation, especially residential ones and especially where plug-and-play solar modules are used, then inverters need to have their settings pre-configured for the grid code in the factory that then cannot be changed by the user or operator in the field. That would be a way to shoe-in this kind of installation.
Hard setting grid codes into inverters prior to shipping to site might be overly conservative though, especially as utilities change their grid codes over time. You need to have a way to update those settings, which could be using a wireless portal hosted by the inverter OEM with credentials made only available to the OEM. Problem with this is that then you shift the burden of configuration to the manufacturer which already has a ton of other UL standards as well as rules and regulations to follow.
What do y’all think?
Dozzi92@lemmy.world 2 weeks ago
I agree with everything you said except shoe-in, because it’s shoo-in.
But you articulated (better than I was going to) the number one issue. Power companies need insurance and their insurance will be affected if ordinance permits basically unchecked generators being plugged into the grid. And before anyone says it, you are not allowed to just plug your generator into your house. Does it happen? Yeah, people have been dumb since day one.
But there are transfer switches that allow for this operation in a safe manner, and the easiest way to deal with this is to have them installed by default in new construction, and to provide incentive for upgrading your panel to include one.
artyom@piefed.social 2 weeks ago
Inverters in the US are all listed to UL1741-SB which dictates that they shall cease to energize their AC outputs if they sense an absence of grid voltage.
No, they are absolutely not. I don’t know where people are getting this idea. Many inverters aren’t even UL listed. There is absolutely no requirement for them to be. If that were the case, off-grid inverters wouldn’t even be allowed to exist. I own several that do not have this capability and are not UL listed.
they need to be checked by a qualified person
Not in the case of Utah’s new “balcony solar” laws. That’s the problem.
which could be using a wireless portal hosted by the inverter OEM with credentials made only available to the OEM
Oh goodie, I’ve always wanted DRM for my inverter.
What do y’all think?
I think it should just require a permit, like every other solar installation. Unless we can provide data to show that it’s not a problem in existing areas where this is common, and we research and follow their regulations.
Resonosity@lemmy.dbzer0.com 2 weeks ago
Many inverters aren’t even UL listed.
Yes but many inspectors and insurance companies won’t want you to install electrical equipment on “real property” or buildings if it isn’t UL as that falls into the scope of AHJs and insurance providers. If there’s something that has the potential to start a fire, you need to have safety certifications so operating the system not only reduces the risk of fire, but also selling the house in the future to a new owner doesn’t come with excess burden on behalf of the next insurer.
If your solar system is off-grid AND off-building, I see no reason that you need to have a UL listed system.
This is of course dependent on local AHJs and utilities, but UL 1741 covers both standalone (off-grid) and grid-interactive (on-grid) inverters. If you’re choosing an inverter manufacturer that makes non-UL listed off-grid inverters, I would probably be suspect of their products’ quality as it’s easier to gain UL listing regardless of how the inverter is used: off-grid or grid-interactive.
That’s the problem.
That is a problem. Off-grid inverters that aren’t certified to UL 1741-SB aren’t required to have anti-islanding protection that cuts the inverters off if there’s an absence of grid voltage. If a “balcony solar” inverter were to NOT cease to energize upon loss of grid and stay islanded, then voltage is introduced to the building’s/community’s shared local distribution system. If work were to be done on that portion of the distribution system or grid where lineman and wireman expect conductors to be de-energized, then you might have injuries as a result. Now, you may be able to say that lineman and wireman should always test for presence of voltage prior to doing work, and as a solar engineer I would absolutely expect folks to do this, but that’s not always the case. People cut corners. And in the event that certain crews cut corners, don’t check for voltage and investigate where the voltage source is, and start touching wires and introducing paths to ground, people can get seriously injured or die.
You may think that because solar panels are current-limited that this fact protects workers in the event of becoming exposed to live voltage, but any combination of voltage and current can kill.
I’ve always wanted DRM for my inverter.
In the context of safety, this is a good thing. Skirting DRM on movies or TVs won’t mean you injure yourself or others or worse. Skirting inverter settings can cause inverters to operate in ways that are unintended, and could hurt people. These things are not the same, and it’s concerning that you can’t see the difference.
Also, having locks on settings means that other bad actors are deterred from changing those settings maliciously, whether intentional or not.
There is not substitute for a qualified person operating and maintaining an electrical system, regardless of voltage.
I think it should just require a permit
Agreed
Buelldozer@lemmy.today 2 weeks ago
Assuming its not cheap piece of crap that isn’t UL listed and that’s where the problem is.
4am@lemmy.zip 3 weeks ago
What happens when someone makes an unsafe backfeed into a downed grid and then other nearby inverters detect the current and bring themselves back online? Is there a way to detect if the load is being delivered from the utility vs from incorrectly configured solar or generator installations?
Some others are arguing back and forth about this elsewhere in the thread and I see the reasoning: unpermitted systems could accidentally energize isolated portions of the grid during downtime, which might trick properly installed systems to also come back online, and you have a runaway effect where there is enough current present to allow addition safety systems to be fooled.
There isn’t any data transmission over the wires; there either is current, or there isn’t. Arguing over permitting is moot - either safety systems can handle this scenario already, or they can’t.
All paperwork does is slow the relief of dependence on the utility, which hurts their profits.
atomicbocks@sh.itjust.works 3 weeks ago
The same thing that currently happens when somebody does that with a gas generator? Linepersons get zapped… people get sued… etc…
There isn’t any data transmission over the wires…
That’s very wrong. Not only can you extend Ethernet in your own home using your power outlets, the power companies have been reading meters this way for decades.
artyom@piefed.social 2 weeks ago
Linepersons get zapped… people get sued… etc…
Kinda seems like something you might want to avoid…
atomicbocks@sh.itjust.works 2 weeks ago
Obviously. I was just pointing out that it isn’t an issue unique to solar.
spitfire@lemmy.world 2 weeks ago
Or if the voltage is too high. Or at least they should be
eleitl@lemmy.zip 2 weeks ago
Too high, too low, or out of frequency range.
spitfire@lemmy.world 2 weeks ago
Yeah, I’m practice I’ve only had the first one happen to me
CMahaff@lemmy.world 3 weeks ago
Hmmm, I wonder how this would affect things in the future where this is widely used.
I.E. if you had both widespread solar usage and some kind of large blackout, would it be hard to get all your solar back online because it’s all in the “waiting for the grid” state? And the grid can’t come back at capacity because all the solar it’s expecting is out?
I assume people smarter than me have this figured out, but just a random thought if anyone knows more.
Rivalarrival@lemmy.today 2 weeks ago
Not just solar - most grid-scale generators have this problem. “Black start” is the search term you want to look for, and Practical Engineering has a good video on the subject.
Basically, only a relative few grid generators are actually capable of black starts. The rest need the grid to be already functioning before they can tie in and start producing.
eleitl@lemmy.zip 2 weeks ago
Yes, starting up a downed grid is a difficult problem. Recovering from a large scale failure could take weeks. Longer, with blown transformers.