Solar panels, photovoltaic ones, produce electricity at times when it is worth nothing on the market.
Strengthening this production is no longer justified. (rte-france.com/eco2mix/les-donnees-de-marche).
Some will retort that one can install a battery. The latter allows for smoothing production over a day. But 4 summer months overproduce and 4 winter months depend on French nuclear power. Without long-term storage over several months, we must find how to produce low-cost electricity in winter.

Photovoltaic current is primarily used to heat water in the boiler coupled with the heat pump.
If this is a good deal for the companies concerned, it is neither for the owner nor for the environment.
Solar panels, thermal ones, produce heat that will be consumed later. The production of energy directly stored to be consumed on-site makes much more sense. Why is there so little talk about this?

Yes, because it makes no sense to build alpine solar parks or panels along motorways if new foundations need to be constructed, which requires hours of machinery and concrete, when we have existing structures. The Yverdon viaduct is a very good example of this. New buildings are there, they already have foundations, there is no reason, except for exposure, not to install them. On a sloped roof, integrated panels even replace standard roofing. On flat roofs, it's now even possible to maintain green roofs under the panels. For façades, I'm a bit more critical about their proper integration. The illustration image is quite telling!

For winter, it's still better than nothing on the plateau. In the Alps, heating panels can be installed. The energy used to clear snow from the panels is quickly offset by more efficient production due to radiation.