Solar insolation curve (click to enlarge)
The concept of solar energy can be abstract. We might know that it is electromagnetic radiation from the Sun, but “WHERE on the electromagnetic spectrum is it?… and “HOW MUCH is there?”
Knowing where and how much gives a person the power of their solar energy inheritance.
Solar Energy is what we’ve always known as light and heat.
It’s composition is: 6 – 7% ultraviolet light; around 42% visible light and 51% near infra-red.
99.9% of the sun’s output of energy occurs between 250 and 2500 nanometers.
We receive solar energy at an intensity of 1 kilowatt per square meter at sea level for many hours of the day.
The amount of sunlight we receive, and at which wavelengths is called Earth’s insolation curve. “Insolation” – see the word Sol? – is the amount of energy received in sunlight.
In looking for a graphic of Earth’s insolation curve I noticed a new one up on the net, courtesy of Newport.com (where they have a good information page on solar irradiance). I’ve added a couple of lines to show the visible spectrum (click on above).
It is the AREA under the curve that represents the amount of energy at those wavelengths.
I also see that the standard used by many these days is this curve. Note that Solar Energy peaks in what we know as our colour blue. Again, over 40% of Solar Energy is visible light.