The base of EHTV calculation is analyzing the dynamic heat transfer to equivalent temperature difference Solar factor of windows, for the shading of windows it used external shading multiplier.

In addition to the internal variability of the global climate system itself, there is the added factor of external influences, such as volcanoes and solar activity.

Even though there's disagreement over how much of the price of solar is tied up in these soft costs, they are clearly an important factor.