When you think of all of the components needed to power a modern home with Photo Voltaic power, it is very expensive. The batteries alone are about $350 each and to run a home to modern standards, you would need a bank of at least 8. That is in addition to the cost of the panels, inverters, regulators, wiring, frames for the panels, tracking motors, etc.
Batteries will eventually not charge efficiently after a few years and have to be replaced.
So the cost of solar energy is more than the cost of the fuel used to create the electricity. Even though the cost of the panels is dropping, it can still take 15-20 years to recover the initial investment in energy savings.