add section separation between Energy sources Solar and Grid

[Mariusthvdb]

right now the visual of the connection between Solar total and the top of the Grid entities is a bit odd. I feel it would be clearer to separate those.

the Solar total doesn't have a bar in front, nor a Cost (only recently realized that it's not the same hierarchy as the Grid ones that do below it ....)

I believe it would be just that bit more perfect, if we had a section Solar, and a separate section Grid there, (maybe even with a sub-header)?