Typically if you can afford a $25k upfront cost, the long term costs are pretty negligible.

If you're paying cash, then your monthly expenses are only going down due to your reduced electricity bill, so your savings potential is going up further.

Additionally the panels are warrantied for at least a decade, with a performance guarantee for 20+ years. If they're installed on your roof, many also include a guarantee on the roof work.

Proactive solar maintenance is really just keeping things clean, which costs very little.

These small costs do add up if you're barely making ends meet and on a lease plan that costs roughly the same as your old utility bill, but for the group paying upfront, ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯