CO2 Emissions Calculator
What is solar insolation?
The amount of electromagnetic energy (solar radiation) incident
on the surface of the earth. Basically that means how much sunlight
is shining down on us.
Why is knowing the insolation level useful?
By knowing the insolation levels of a particular region we can
determine the size of solar collector that is required. An area
with poor insolation levels will need a larger collector than
an area with high insolation levels. Once you know your region's
insolation level you can more accurately calculate collector size
and energy output.
What units are used to express Insolation levels?
The values are generally expressed in kWh/m2/day.
This is the amount of solar energy that strikes a square metre
of the earth's surface in a single day. Of course this value is
averaged to account for differences in the days' length. There
are several units that are used throughout the world.
The conversions based on surface area as follows:
1 kWh/m2/day =
317.1 btu/ft2/day = 3.6MJ/m2/day
The raw energy conversions are:
1kWh = 3412 Btu = 3.6MJ = 859.8kcal
Is my region's insolation level
low, moderate or high?
The following scale is a basic guide for insolation levels. Although
a value of 5 is not considered very high during the summer months,
as an average annual value this is very high. You will see that
in central Australia, which is a hot, sunny place, the annual
average insolation is 5.89.
You may compare you location to the following
two extreme locations.
Average annual insolation levels:
Central Australia = 5.89 kWh/m2/day
- Very High
Helsinki, Finland = 2.41 kWh/m2/day
- Very Low
Now I know my insolation level, how do I
calculate my collector's size?
Please click
here to visit the collector sizing page.
Click on the links below to view insolation levels for your
region.
If you would like to find the insolation
levels for your area, please visit the NASA website below.
You just need to know your latitude and longitude. Free
registration at the site is required for access.
Nasa
Surface meteorology and Solar Energy Data Set
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