Peak Sun Hours

Peak sun hours are a measure of the energy emitted from the sun at a given location. 1 peak sun hours = 1000 watt or 1kw of solar power reaching the surface over the duration of an hour. On average we get about 6-8 peak sun hours each day on a surface of 1 square meter and this equales 6kw/h. Solar wattage is also rated against peak sun hours.

To easily calculate the output of electricity per day that your solar panel will produce. Take its wattage and multiply it with the amount of peak sun hours. I.E, 180watt solar panel, with 6 peak sun hours would produce. 180watts * 6 peak sun hours = 1080 watt/hours or about 1kw/h each day.

But the amount of peak sun hours in locations varies alot, so how can you predict it?

When calculating this number we need to take into account some weather data, luckily the amount of sun in various places in the world have been recorded for each year for a long time and we can get information about the amount of sun, by figuring out the solar irradiance or “peak sun hours”, this number is the power of the suns rays at a horisontal plane at the surface of the earth that is one square meter, and it is given in kw/h per square meter. Since the peak sun hours are on a horisontal surface, and since we dont let the solar panels lay straight on the ground but instead tilt them with an angle towards the sun in the north hemisphere and the exact opposite in the souther hemisphere, these numbers are to low, but give a good idea of the amount of sun a location gets.

The peak sun hours varies alot with your location. The most Peak sun Hours can be seen along the equator where the suns rays hit the earth at an more direct angle than at the north and the south poles. This number varies from about 3 – 7.5 Kw/h per square meter each day.

If you consider installing solar panels in your home, peak sun hours is one aspect you need to understand very well, as it can outweigh many of the benefits of going solar if you install the solar panels in the wrong location.

If we want the most energy output we might want to install a solar tracker since the most output of electrical energy is seen when the solar panel is pointing directly at the sun. Installing one can give you improvements of 30%, you can either use a passive tracker or and active tracker. Or you can set up your panel with an angle that gives you the most power during the year without using a device to track the sun.