[ssdd]

Initial cost might be high but this cost would be slowly return as you save on electricity bills. Also, all this equipment is not perishable and you can still re-sell at good price after your retirement or sell them along with house. Its no different than investing in house upgrades which adds to the house value.

[tjohns]

Both the solar cells and the batteries have a finite lifespan, and will eventually need to be replaced.

Especially the batteries.

[heavyheavy]

Inverters have to be replaced as well.