Questions About Solar Charging

[erict]

I am planning improvements to my charging system but am stuck on some questions related to solar.

One point of confusion for me comes from browsing posts about wind/water generators and the need to dissipate excess power. Basic question is: is there a similar need in solar charging systems to handle excess power? What happens to solar current generated by the panel but not consumed by the system either due to low demand or a disconnect between panel and controller?

[heyniceguy]

From my understanding, solar panels do not require excess charge to be dissipated. They may be unplugged fully (no load) and it will not hurt them to be exposed to the sun.

Wind generators, tow-behind generators, alternators require someplace to sink the excess current they generate (like a 12V element in the hot water tank).

I may be wrong but im pretty sure im not.

[noelex 77]

In simple terms solar and wind regulators work differently.
A solar regulator turns the solar panel off and on rapidly to achieve the desired voltage.
A wind regulator diverts the excess power so it is converted to heat.
The reason for this difference is a solar panel when open circuit (disconnected from the battery) does not cause any problems.
A wind generator when open circuit (disconnected from the battery) speeds up, because there is no load, and can exceed it design parameters and speed. A wind regulator needs to keep a load on the wind generator when regulating, solar panels can have no load without damage.

[goboatingnow]

solar regulators can be series pass, or PWM ( switching), series pass effectively converts excess energy into heat, switch mode is more efficient.

wind generators have traditionally been DC permanent magnet generators, which need a constant load in order to control speed ( thoses without brakes or feathering). There are more modern alternators based units that control charging via field current control and hence dont need load dumps.

Dave

[Unicorn Dreams]

My KISS Windgen will shut off automatically when needed and the blades stop turning...

[erict]

Thanks for the definitive answers. I have more questions which I'll put in another thread.