A Question about Lots and Lots of Solar Panels

[SolarHead]

something I have wondered about but have not asked or researched

when I was designing my system, I got help on the forum from some super smart and very generous people and they had to know what inverter I had, and its limits for PV voltage, and amps. So, we figured out how many panels I could do on each MPPT and stay within the inverters limits

my dumb question is;
why wouldn't they make an inverter or device that you could connect say crazy amount, any amount of solar panels to it, without any worry that you might over-power and blow something up ? I mean, hook up 850 solar panels and then the device or the inverter will only accept what it can based on its limits and the excess power is not even generated, the panels are not "asked" to make the power so no fear of importing too much to your equipment. It would just be a huge waste of money and time, but it would not hurt any of your equipment. I was like why the heck are we having to calculate how many panels I can connect? That's a pain and recipe for disaster if you ask me. I mean, over-panel, and then the inverter can take what it can take. I keep thinking okay on cloudy days, what if I had like 150 panels and I maxed out my inverter, and on sunny days, I maxed it out then too (of course). Both times, no worries of over powering or burning anything up.

 

[HRTKD]

Money. To create something that can either damp down the voltage or handle any voltage costs more money.

 

[timselectric]

You can over panel on amperage.
Just don't do it on VOC.

 

[Bobert]

something I have wondered about but have not asked or researched

when I was designing my system, I got help on the forum from some super smart and very generous people and they had to know what inverter I had, and its limits for PV voltage, and amps. So, we figured out how many panels I could do on each MPPT and stay within the inverters limits

my dumb question is;
why wouldn't they make an inverter or device that you could connect say crazy amount, any amount of solar panels to it, without any worry that you might over-power and blow something up ? I mean, hook up 850 solar panels and then the device or the inverter will only accept what it can based on its limits and the excess power is not even generated, the panels are not "asked" to make the power so no fear of importing too much to your equipment. It would just be a huge waste of money and time, but it would not hurt any of your equipment. I was like why the heck are we having to calculate how many panels I can connect? That's a pain and recipe for disaster if you ask me. I mean, over-panel, and then the inverter can take what it can take. I keep thinking okay on cloudy days, what if I had like 150 panels and I maxed out my inverter, and on sunny days, I maxed it out then too (of course). Both times, no worries of over powering or burning anything up.

Probably to expensive.

 

[wattmatters]

High voltage DC is a bugger.

Even commercial inverters of 50 kW capacity are 1000 V limit, similar to many grid tied residential inverters.

Some solar farm inverters have 1500 V limits.

 

[MajicDiver]

You can over panel on amperage.
Just don't do it on VOC.

I have been thinking that the only thing that matters is the VOC limit. But I haven’t seen an explanation of why most if not all inverters specify a Isc limit also? Can you explain why they specify the limit?

 

[timselectric]

That's the limit that the SCC can safely pass through its circuitry, without overheating.

 

[JRH]

I sorta think if you had 500 panels somehow arranged in your yard you would have a swarm of Dept of Inspections people with clipboards crawling all over the place writing you up with countless violations for everything possible, including your dog being too fat…They would skip lunch get that chance … it’s a genetic thing..

 

[Bvillebob]

They make lots of solar charge controllers like that, just not the cheapest ones. It's basic electrical design to monitor the output current and component temperatures and to limit the output of the charge controller to a safe level. My controllers are rated at 94 amps, they're hooked up to arrays capable to supplying twice that. I have them set to a max output current of 80 amps this time of year when it's so hot so that's all they put out even when the panels are capable of delivering more than twice that current. I do this so that on winter days when it's overcast all day I get twice as much power over the course of the day than if I only had the "correct" amount of panels for my controllers.

They're not cheap, they're not available on Alibaba, but they are well engineered.

 

[SolarHead]

All interesting comments, well, the dog being too fat inspection violation was pushing it but overall interesting. I was thinking why not dummy-proof it where the inverter only takes in what it needs, regardless of how much PV you have available, and without any possibility of overloading or burning/blowing something up.

 

[SolarHead]

Only one inspector would walk onto my property, without my permission.

I don't know if they need permission in some cases.

 

[Bluedog225]

Only one inspector would walk onto my property, without my permission. After they caught one of my bullets, the rest wouldn't risk it.

You should not say this, even as a joke.

 

[Bluedog225]

This is an interesting question.

Why not a DC voltage regulator between the panels and the controller? Maintain voltage by sending excess current to ground. Fail safe.

I wonder how much this would cost? Maybe cheap insurance for a pricey controller.

 

[Bobert]

I don't know if they need permission in some cases.

In the USA technically no inspection can be done on private property without permission or court order. In some states this a bit more practical like in Texas where in many areas deadly force is permitted to defend that right. In reality you must give permission or you will not get your permit or you will not be allowed to finish without danger of litigation. So the right to not be searched is essentially made null and void by our present Zoning/permitting practices.

 

[Bluedog225]

In the USA technically no inspection can be done on private property without permission or court order. In some states this a bit more practical like in Texas where in many areas deadly force is permitted to defend that right.

You are wrong. This is not the law in any jurisdiction in the United States.

This has never been the law going back to English common law.

It is irresponsible to say this.

 

[timselectric]

All interesting comments, well, the dog being too fat inspection violation was pushing it but overall interesting. I was thinking why not dummy-proof it where the inverter only takes in what it needs, regardless of how much PV you have available, and without any possibility of overloading or burning/blowing something up.

SCC's do draw what they need from the solar panels.
Solar panels just make what they can produce available. The only issue is with voltage. That's set by how the solar panels are wired. And needs to be based on what the SCC can handle.

 

[timselectric]

You are wrong. This is not the law in any jurisdiction in the United States.

This has never been the law going back to English common law.

It is irresponsible to say this.

The only people allowed to come on your private property, without permission. Are law enforcement and emergency responders. Everything else is trespassing.

 

[timselectric]

You should not say this, even as a joke.

Was not a joke.

 

[Bluedog225]

Was not a joke.

Then it’s a foolish thing to say and inconsistent with state law (all states and U.S. jurisdictions) and federal law. It is the very definition of “un-American.”

You are proposing the murder of a govt. official carrying out their legitimate duties. E.g. a game warden may have the legal right to enter your property under certain conditions. Or a firefighter. Or someone who has had an accident and is looking for help.

And people will read what you have written and believe it to be true. It is not.

And fundamentally, from your post history, it looks like you are smarter than most. And you, of all people, should not foster and contribute to this belief system.

Peace.

 

[timselectric]

Then it’s a foolish thing to say and inconsistent with state law (all states and U.S. jurisdictions) and federal law. It is the very definition of “un-American.”

You are proposing the murder of a govt. official carrying out their legitimate duties. E.g. a game warden may have the legal right to enter your property under certain conditions. Or a firefighter. Or someone who has had an accident and is looking for help.

And people will read what you have written and believe it to be true. It is not.

And fundamentally, from your post history, it looks like you are smarter than most. And you, of all people, should not foster and contribute to this belief system.

Peace.

In my area it's common practice to not allow surprise inspections on job sites. The inspector is told to leave, and return with a warrant. This process takes 3 days. And gives the contractors time to conduct their own thorough inspection and correct any violations.
If they refuse to leave, they can be arrested for trespassing. This is the law.