Battery Equivalents and Replacements

Do Sun Panels Need Direct Sunlight To Operate?

With more and more people using solar panels to power their homes and to recharge their electric vehicles, RVs, golf carts, and similar, more and more questions regarding solar panels are being asked.

One of the very common questions is if solar panels need direct sunlight to work.

Published: October 24, 2022.

solar panels and clouds 1

Quick Answer: No, solar panels don't need direct sunlight to work. However, they work best, i.e., they collect the most sunlight and produce the most energy when they are properly oriented toward the sun and when there are no obstacles (clouds, for example) between the sun and solar panels.

How Do Solar Panels Work?

Solar panels consist of photovoltaic elements that convert incoming photon particles into electric energy.

Each solar panel consists of several photovoltaic elements connected in series and/or parallel in order to provide a certain power under certain conditions - these conditions are usually full sunlight simulated in a lab environment.

Note: Average solar panel may consist of dozens of photovoltaic elements.

For the solar panel to produce the most energy, it must collect the most sunlight - the more photons, the better.

And the light/photons are present during the day, even under clouds or in the shade, just their numbers can be much lower than during the clear sky.

Also, to collect more sunlight, the solar panels must face the sun at the proper angle - if the solar panels are turned, for example, 45° to the side away from the sun, their effective surface is decreased down to ~70.7% of their nominal surface.

That is why some electric car (and similar) solar charging stations utilize solar panels combined with sun-tracking sensors, which may significantly increase the energy efficiency of the solar charging system - in such systems, solar panels follow the sun just like sunflowers.

solar panels and clouds 2

How To Increase Energy Efficiency Of Solar Charging System

There are several ways of increasing the energy efficiency of solar charging systems, but they all require additional investments.

However, solar charging systems are built to last for years and decades, and just a small increase in energy efficiency may lead to large energy savings in the long run - it also means more money for the owner.

These methods include:

  • Check the solar charge controller. PWM charge controllers operate at 80-85% energy efficiency, while MPPT charge controllers operate at 95-96% energy efficiency.
  • Check cable thicknesses. Most cables are dimensions for a voltage drop of up to 3%. Having thicker cables can decrease energy losses.
  • Check the cable length - the longer the cables, the greater the losses.
  • Check the connections and connectors and if required, replace them. Gold-plated connectors do cost more, but they ensure much better contact than regular ones, etc.

Of course, there are other methods to increase the energy efficiency of your solar panel system, these are just the most common and the most obvious ones.