Solar panel considerations

Having renovated our house recently with an air-to-water heat pump, we consider investing in solar panels, reducing the cost of electricity.

Many different solutions exist, from which we have to choose. But one question caught my interret. No matter what the choise of panel is, what is the optimal direction, and how many would be needed of a certain kind in order to cover our need?

First things first…

Optimal direction of solar panels

Calculating the annual solar irradiation is interresting stuff. You get to know – and to some degree understand – astronomical term such as the earth’s orbit around the sun, the earth’s declination, and so on. I’m not an astronomer, but does have the necesary knowledge about math (and “geometry”) to understand the math behind all of this. Lets move on…

The following is a unfolded description of the algorithms presented in

Reda, I., Andreas, A. (2003) Solar position algorithm for solar radiation application. National Renewable Energy Laboratory (NREL) Technical report NREL/TP-560-34302. 

Available from here.

NOW, lets move on.

Terms and nomenclature

Azimuth and Zenith

Cosinus-projection