jimindenver
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Panels are rated in a lab under specific conditions. Rarely do we see those conditions in real life.
New panels can produce higher output in the beginning. Ratings are for the average over the life of the panel.
Ratings are set up for sea level and 77 degrees. Both higher altitude and cooler temperatures can cause the panel to out produce the rating.
Higher altitude means thinner and cleaner air.
Cooler temps create less resistance in the panel.
Combine new panels at higher altitudes with cooler temperatures and you can see quite the boost over the rated output.
Some examples
I had a 220 watt mono panel rated for 36 volts jump to 40 volts in freezing temps and then settle to 38 volts once it started working.
a 230 watt panel in freezing temps produced 2 more amps to the battery than was its norm.
Bob tells of a friend that was traveling over Independence Pass in Colorado on a cold, cloudy day when the sun popped out causing the voltage of the panels to spike frying his controller.
The other thing that can cause it is called cloud or edge effect. As a cloud passes the sun the edge illuminates very brightly because it is reflecting the sunlight that normally would not be directed at your panels. As long as the cloud is close enough your panel will see two light sources instead of one. The only downside beyond damaging a controller that is too close to its limits is that cheaper controllers like a epever do not cycle fast enough to adjust and a full or nearly full battery can go above 15 volts briefly. A inverter will shut down if the voltage exceeds 15 volts even momentarily and quite possibly the BMS in a lithium battery will too.
New panels can produce higher output in the beginning. Ratings are for the average over the life of the panel.
Ratings are set up for sea level and 77 degrees. Both higher altitude and cooler temperatures can cause the panel to out produce the rating.
Higher altitude means thinner and cleaner air.
Cooler temps create less resistance in the panel.
Combine new panels at higher altitudes with cooler temperatures and you can see quite the boost over the rated output.
Some examples
I had a 220 watt mono panel rated for 36 volts jump to 40 volts in freezing temps and then settle to 38 volts once it started working.
a 230 watt panel in freezing temps produced 2 more amps to the battery than was its norm.
Bob tells of a friend that was traveling over Independence Pass in Colorado on a cold, cloudy day when the sun popped out causing the voltage of the panels to spike frying his controller.
The other thing that can cause it is called cloud or edge effect. As a cloud passes the sun the edge illuminates very brightly because it is reflecting the sunlight that normally would not be directed at your panels. As long as the cloud is close enough your panel will see two light sources instead of one. The only downside beyond damaging a controller that is too close to its limits is that cheaper controllers like a epever do not cycle fast enough to adjust and a full or nearly full battery can go above 15 volts briefly. A inverter will shut down if the voltage exceeds 15 volts even momentarily and quite possibly the BMS in a lithium battery will too.
