Transport grids aren't free, and excess electricity production is bad as it requires curtailment (wastage) which isn't free either to prevent damage to electric equipment (very expensive).
Besides, when renewables produce these excesses, this will often be the case in a very large area.
The existing solution isn't economical, mostly due to grid costs. If you want it, it'll have to come from the tax payers pocket, which means it has to compete with stuff like healthcare.
Religion is a choice, an unverifiable one at that. There is no reason that such a choice should grant special privileges that someone non-religious, or of another religion would not be granted. Each such request must stand on its own merit.
In Europe the concept of freedom from religion is something that many different cultures have fought hard for - secularism.