question about parking your solar topped camper under fluorescent lights at night

[AbleGuy]

I'm still trying to figure this one out…

We read in the owners info for our camper van which has two hard panel solar panels on the roof that we should not park it at night with the solar power connected while under fluorescent lights, such as street lights or parking lot lights, etc… Because that light emitted from those sources would confuse the MPPT controller and have it cycling on and off all night, and then that would wear it out prematurely!

That kind of caution seems hard to understand when you think about how many campers have solar panels on their roofs and are park under lights at night in campgrounds or RV parks or on streets, etc.

Is this issue really a thing, and have any of you guys read of or been warned about this ?

 

[craig333]

Never heard that one before.

 

[FrenchieXJ]

Maybe contact some of the manufactures of solar panels and solar equipment. I had never heard of that one either.

 

[ThundahBeagle]

worst to worst, could you fashion a sort of kayak cover to slip over the solar when parked overnight

 

[rruff]

They'd have to be extremely bright lights to even register. There should be a switch to turn off the input/charge circuit as well... and if there isn't one, you could install one.

 

[tencentlife]

You should have a hand-operable parallel breaker in the post-combiner PV array positive line and the positive controller to battery wire, such that the charge controller is between the breakers and throwing it operates both simultaneously. This isolates the array, controller, and battery from each other with one action. This is standard PV wiring safety practice. Open that breaker at night if you're parked under artificial light sources of any kind, and you don't need to wonder whether excessive cycling will cause long-term damage to the controller. It would be a hard thing to prove anyway without specific long-term testing, so the manufacturer is probably advising out of an abundance of caution (because they do that), but in any case, if you do that you've eliminated the possibility of problems.

 

[AbleGuy]

Hey, thanks all for your comments.

I finally gave in and asked AI...here's the response:

Importance of Disconnecting Solar Systems at Night​

Potential Issues with Bright Lights​

When parking a camper with solar panels under bright lights, such as street or parking lot lights, it is advisable to disconnect the solar system. The primary concern is that the light can confuse the solar charge controller, particularly the Maximum Power Point Tracking (MPPT) controller. This confusion may cause the controller to cycle on and off throughout the night, which can lead to premature wear and tear.

Recommended Practices​

To prevent potential damage, consider the following practices:

• Disconnect the Solar System: Use a manual switch or breaker to disconnect the solar panels from the battery and charge controller when parked under bright lights.
• Install a Switch: If your system does not have a built-in switch, consider installing one. This allows for easy disconnection when needed.
• Monitor Conditions: If you frequently park under bright lights, regularly check the performance of your solar system to ensure it is functioning correctly.

General Advice​

While many campers park under lights without issues, taking precautions can help extend the life of your solar equipment. Disconnecting the system at night is a simple step to avoid potential problems caused by artificial lighting.



So I may just craft some kind of a clothe cover for now.

The area where my solar plug/unplug resides is too cramped to easily install a disconnect and the rest of the wires are inaccessible, being hidden behind cabinets, etc.

 

[86scotty]

Here's my uninformed answer. I think AI is guessing. Who cares if your controller cycles on and off at night? It probably does it all day as you pass under shadows while moving.

And what exactly is 'premature wear and tear' on a charge controller? It's more or less an intelligent switch and by definition, will last until it doesn't.

 

[ThundahBeagle]

Hey, thanks all for your comments.

I finally gave in and asked AI...here's the response:

Importance of Disconnecting Solar Systems at Night​

Potential Issues with Bright Lights​

When parking a camper with solar panels under bright lights, such as street or parking lot lights, it is advisable to disconnect the solar system. The primary concern is that the light can confuse the solar charge controller, particularly the Maximum Power Point Tracking (MPPT) controller. This confusion may cause the controller to cycle on and off throughout the night, which can lead to premature wear and tear.

Recommended Practices​

To prevent potential damage, consider the following practices:

• Disconnect the Solar System: Use a manual switch or breaker to disconnect the solar panels from the battery and charge controller when parked under bright lights.
• Install a Switch: If your system does not have a built-in switch, consider installing one. This allows for easy disconnection when needed.
• Monitor Conditions: If you frequently park under bright lights, regularly check the performance of your solar system to ensure it is functioning correctly.

General Advice​

While many campers park under lights without issues, taking precautions can help extend the life of your solar equipment. Disconnecting the system at night is a simple step to avoid potential problems caused by artificial lighting.



So I may just craft some kind of a clothe cover for now.

The area where my solar plug/unplug resides is too cramped to easily install a disconnect and the rest of the wires are inaccessible, being hidden behind cabinets, etc.

A second awning, but facing towards the vehicle si it can sit a couple inches above and covering the solar array, if you dont install a switch

 

[ThundahBeagle]

Here's my uninformed answer. I think AI is guessing. Who cares if your controller cycles on and off at night? It probably does it all day as you pass under shadows while moving.

And what exactly is 'premature wear and tear' on a charge controller? It's more or less an intelligent switch and by definition, will last until it doesn't.

I doubt the controller is fast enough to respond and react to passing under, say, individual overpasses and such during the day driving at highway speeds
Unless of course you get stuck in traffic at Fenway or Gillette

 

[AbleGuy]

A second awning, but facing towards the vehicle si it can sit a couple inches above and covering the solar array, if you dont install a switch

that's kind of an interesting and creative idea

 

[DaveInDenver]

For what its worth, the luminaires I most recently spec'd produced 5000 lumen at 4000K on a 30 foot pole. At grade (in other words, on the street) the datasheet says they produce 0.5 foot-candle, which is the same as 0.5 lumen per sq-foot. This would be approximately 5.38 lumen per sq-meter. They draw about 50W which therefore gives an efficiency of 100 lm/W.

I'm not sure how exactly that translates to solar panel irradiance and wavelengths (other than lumens and color temperature). They don't spec it that way.

But a typical solar panel, say a 100W monocrystalline, produces rated power based on 1000 W/m^2 of sunlight (which is assumed to be 5000K to 6500K usually depending on your criteria for haze and incidence and such). If this example panel is 39" x 22" surface area that would be 858 sq-in (or roughly 0.55 sq-m) at say 18% efficiency to get 100W from 1000 W/m^2.

Therefore that same panel under one of our streetlights probably will produce something like a max of 3W, probably less due to color temp.

So it's not zero but whether that's enough to produce a voltage or any real power from the panel, at least enough that will cause a solar controller to turn on, will depend. I doubt it. I'd think any good MPPT controller will sense this as twilight and dusk/dawn and not try to make power from the solar side. As long as there's battery side power the MPPT control microprocessor and it's algorithm should be on and active.

That said, it's good practice to have a way to disconnect the solar panels and there's not really any downside to doing that in this situation.