Solar radiation simply refers to the quantity of electromagnetic energy/solar radiation that can reach the Earth's surface, which means how much sunlight we can get.
Why is knowing solar radiation levels useful?
If we know the solar radiation level in a particular region, we can determine the size of solar collectors we need. Generally, areas with abundant solar radiation require fewer collectors than areas with poor solar radiation. By knowing the solar radiation level in your area, you can calculate the collector size and energy output more accurately.
What units are used to express solar radiation levels?
Different countries use different units to express solar radiation levels. However, a common unit is kWh/m2/day, which means the amount of solar energy a square meter of Earth's surface can absorb in one day. This figure is an average value for different day lengths and temperatures.
The conversions for different units based on surface area are as follows:
1 kWh/m²/day = 317.1 btu/ft²/day = 3.6 MJ/m²/day
The original energy conversion is as follows:
1 kWh = 3412 Btu = 3.6 MJ = 859.8 kcal
Is the solar radiation level in my area low, moderate, or high?
The following example shows the solar radiation level in a region. An average annual value of 5 is considered a very high figure, although it is not considered very high during the summer months. In hot, sunny locations, such as central Australia, the annual average solar radiation is only 5.8g. The average solar radiation is 5.89.
You can determine the solar radiation level of your location by comparing it to the following two extreme locations:
Average annual solar radiation levels:
Central Australia = 5.89 kWh/m²/day - Very high
Helsinki, Finland = 2.41 kWh/m²/day - Very low
Now, how can I calculate my collector size based on my solar radiation level?
Click here to visit the collector sizing page
Click on the link below to see the solar radiation level for your area
You can find the solar radiation level in your area by visiting the NASA website below.
Latitude and longitude are basic information for finding the solar radiation level in an area, but you should first have free registration at the site.
