Solar energy produced from a solar panel is determined by how many photons from the sun strike the solar cell, and how many of these photons actually get an electron moving to create a current. This is how a charge from a solar panel is produced.
On cloudy cover days, with rain, humidity, air pollution, or dust in the atmosphere, much of the solar radiation is scattered, meaning the energy that comes from the sun goes in different directions. We call this diffuse radiation, solar energy but its rate is smaller. This is opposite to direction radiation which is when the sun’s energy comes in a beam of straight rays without interference like on a clear dry day with no dust and humidity.
Solar panels will charge during the day even when it’s cloudy because there is some light hitting them. However, the efficiency is greatly reduced. On a cloudless day solar panels should be producing about 30% more energy than on a cloudy day since the sun is much brighter and so can reach them better
What you can do to get more power
Unless you are in a storm cloudy weather should come and go. But they are some things you can do to get more out of your solar system.
Size your system appropriately
Your solar panel system will provide output according to the peak sun hours. The term “peak sun hours” refers to the solar insolation which a particular location would receive if the sun were shining at its maximum value for a certain number of hours.
The output of a solar panel is usually stated in watts, and the wattage is determined by multiplying the rated voltage by the rated amperage. The formula for wattage is VOLTS times AMPS equals WATTS. So for example, a Solar panel rated 18V providing 3 amps will be rated 54 watts (60 watts in most cases)
V x A = W
18 volts times 3 amps equal 54 watts
If an average of 6 hours of peak sun per day is available in an area, then the above solar panel can produce an average of 300 watt-hours of power per day; 54w times 6 hrs. = 360 watt-hours.
For you to get the same output in less favorable conditions you may need to add other panels to the system or get a panel rated higher.
Use High Efficient Solar Panels
You can find three different types of solar panels in the market. Polycrystalline, monocrystalline, and Thin-film Solar panels. Monocrystalline solar panels have the highest efficiency among the three. The new ones can reach up to 23% efficiency. They will perform better in cloudy conditions than similarly rated polycrystalline and thin film solar panels.
However, some devices like a 5-watt Solar trickle charger for a car battery will continue to work effectively as they do not require much sunlight.
Wiring Panels in Series or Parallel
You wire solar panels in series or parallel to increase voltage and amperage. Wiring solar panels in series will add up the voltage while wiring them in parallel will add up the amps. You can also wire them both in series and parallel which will increase both volts and amps.
Wiring Solar panels
Use an MPPT Charge controller
Because the MPPT controller is always tracking the maximum power point it can react quickly to changes in the input Voltage. This includes when there are passing clouds that can read to a drop in voltage.
Use a Battery bank
A battery bank will help you get the power you need when the grid goes down or during tough weather conditions. Battery banks are also great for storing solar energy so that they can be used at night, on cloudy days, or while on vacation in your off-grid cabin.
