Solar energy-related technology is a very fast-growing field. Many tend to use this energy a lot as it gives more benefits to them and also saves the environment, unlike fossil fuels. Fossil fuels are becoming very costly and also pollute the environment during the extracting process. Solar energy is renewable energy so we do not have to be afraid of running out of solar energy. Solar energy is a free source so you only have to worry about the installation fee. Unlike grid power, you do not have to worry about the monthly bill. But before using solar energy it is better if you have a brief idea about how these solar-powered equipment works to get the most out of them. As we all know to generate current from solar power we use solar panels. The produced amount of current depends on the amount of sunlight received by the solar panels. When using solar panels many get the question about the best time of the day for the solar panels.
The best time of the day for solar panels or the time that your solar panel gets enough sunlight to generate output with good efficiency mainly depends on the orientation of your solar panel. Normally on a sunny day, solar panel facing north receives most sunlight during 10 am to 2 pm and panels facing west produce more current in afternoon and panels facing east produce most energy during morning hours. Anyway, usually solar panels receive sunlight throughout the day. But to name the most efficient hours of the day for solar panels, there is a term called “peak sun hours”.
Before going any further let’s have a brief idea about the working principle of a solar panel.
How does a solar panel work?
Many assume that to generate the current from the solar panel you need the heat of the sun. But that assumption is totally wrong. What you really need is sunlight. When the light photons/ light energy particles hit the solar panel the energy is absorbed into the atoms of the solar panel. Solar panels are mostly made out of crystalline silicon. When the atoms absorb the energy, there will be an ionization of atomic electrons due to the increased energy. These free electrons will flow in one direction through the panels. A current (direct) will result in the opposite direction. This current will be stored in a rechargeable battery for later usage or will be directly used.
So as you can see the power output of the solar panel depends on the intensity and the duration of the sunlight it received, not on the heat.
How to find the best time of the day for your solar panel?
The time you can get the best efficiency from your solar panel is mainly dependent on the orientation of your solar panels. But also the time can be varied according to the seasonal difference and the geometry of your country.
Follow are the best times for your solar panel during a normal sunny day (according to the orientation of your solar panel);
- North/ south – 10 am to 2 pm
- West – during afternoon hours
- East – during morning hours
Usually, the highest solar generation during a sunny day can be seen from 11 am to 4 pm.
Solar panels that face west/ east produce power 20% less efficient than panels facing north/ south.
Most suitable orientation for your solar panel;
For countries in the southern hemisphere – facing north
Reason – for the countries in the southern hemisphere at this orientation your panel will face the longest axis from east to west. So this allows your panels to be exposed to the sunlight more time of the day.
For countries in the northern hemisphere – facing south
Reason – for the countries in the northern hemisphere at this orientation your panel will face the longest axis from east to west. So this allows your panels to be exposed to the sunlight more time of the day.
Tilted 20 – 30 degrees or minimum 10 degrees – as we know from sunrise to sunset sun is not at a constant level. It goes up and down. To get the most out of the available sunlight it is better to angle your panel as it exposes your panel more. Also, this allows the self-cleaning of the panel.
How the seasonal differences affect the best time for the solar panel?
As we all know winter has shorter day times compared to the summer. So the time duration that solar panels can work with good efficiency is limited during winter.
But that does not mean that solar panel works at its best efficiency during summer. Solar panels are tested at 250. During summer the surface temperature of the solar panel can be increased beyond the tested temperature. This incident negatively affects the efficiency of the panel. The reduction of the efficiency can be calculated by the temperature coefficient. So the best time for the solar panels mostly limited to morning hours and evening hours when the temperature of the environment is low.
How the geometry of your country affects the best time for your solar panel?
Countries near the equator receive sunlight with high-intensity during most of the day as the sun is directly ahead of these countries. Also, these countries do not experience seasonal differences as the countries which are more further north. In the countries further south or north the sunlight strikes the earth at low angles. So they receive sunlight with less intensity as the sun rays have more atmosphere to cut in.
What is the peak sun hour?
Even though you have sunlight throughout the day peak sun hour is a great indication to get an idea about the availability of sunlight to produce solar power with enough efficiency in your region.
During peak sun hour the intensity of sunlight is 1000 watts per square meter.
Your solar installation will be more effective if the average peak sun hour is around 3 to 4 days.
Even though you have enough sunlight if your panels are shaded it will not produce power effectively. So make sure there are not many tall trees or any structures that block the sunlight.
| Conclusion |
As we described in this article the best time for your solar panel is mainly dependent on the orientation of your solar panel. The geometry of your country and the seasonal differences also have major roles when deciding the best time for your panel. Peak sun hour is very useful in deciding whether the region you are living in has enough sunlight to produce power efficiently. By having a good idea about the sunlight availability in your area before installing a solar system you can have a good result from your investment.