Solar panels are not voltage sources (28 - Electricity Distribution)

[@s.u.n.t.a.n6573]

Really great video! Super well explained

[@spanishflew]

Good video. well presented and to the point

[@Hossein118]

Commenting on behalf of a non-subscriber: “You are very smart!”

[@samueladitya1729]

what happen if the solar panel with no light applied external negative voltage to its terminal? will the current pass through or get blocked assuming the bypass diode is removed?

[@sammyjoe2390]

Not emphasized in this video, but good to know: When solar panels are in the shade the power lost is due to a decrese in CURRENT not voltage. Voc is usually achievable even in full shade, but Isc max is only seen in full sun. This is important to know, such as in designing charge controllers, because the solar voltage must always be sufficiently above battery charging voltage or the system shuts down. There is no need to add some feature like a buck-boost, because by the time your voltage has decreased low enough, you don't have any current anyhow. My observation on the Internet is that NOBODY understands the science behind how solar panels work. My entire education in Electronics Engineering did not prepare me to design with non-linear power sources. This means that 99% of all people using and installing solar are doing so by "cook book" knowledge rather than a coherent understanding. The experiment here involved a non-inductive load (resistor). What happens when a DC motor is driven directly by a solar source? Take, for example, a DC motor with 12V/2A power requirement. If you use a 12V solar panel, the voltage will be too low because as soon as the current ramps up, the voltage will drop. My guess is that you could match a panel such that the panel voltage reduces sufficiently such as not to "damage" the motor. The problem here is that everything you think you know about DC motors is based on constant V or constant I source- not a variable I/C source. Maybe it turns out that you only need to match power requirements for the motor and let the voltage and current balance themselves. We don't know, because schools (when I went to school) didn't teach such things. (Obviously, if you use electronics between the panel and the motor, it will work, but now you are introducing extra costs and reducing efficiency.) Seeing things like panels facing North and panels installed under shade trees (by "professionals") make it very clear to me that people in the solar panel business either don't understand how they work, or they take advantage of customers who equally do not understand. I am glad to find videos like this that can give me an intuitive feel for what to expect from solar panel performance.