Selling that excess power is possible, as is buying some extra panels - there is enough space for at least 36 more on just that single roof. For now I choose to add panels - and batteries in the not too distant future, once the market is flooded with used EV-batteries - and continue on my course of decentralising the 'net using 'old' hardware - not a single new product is used in any of my computing endeavours. Most of it is either dumpster-dived and repaired, bought 2nd hand or acquired through places like Freecycle.
I also like recycling electronics but some stuff is just not worth keeping powered on. If you can sell electricity back then your switch has an opportunity cost of (assuming 11¢/KWh, which is US avg for 2021 and 5W idle for the replacement switch) ≈45 USD/year, which is almost 90% of its value.