[Pontiac]

For me, at my age replacing the system in 20-25 years is not something I would consider.

I will probably go with a NG powered whole house generator with propane backup.

I have NG at the house and propane is easily available

The systems can be set to start themselves up periodically to run a self-check, so ensuring that they do not deteriorate from being idle.

The cost of the units has come down over that past few years and is I think considerably more affordable than a solar panel system. Also the foot print of a unit is much smaller.

[njmaugbill]

Roof top solar power generation is just a simple distributed generation of electricity. Similar to distributed computing like the SETI at home project.
At critical mass, generating plants can be used less.
I have Solar Panels I send more out than i use. In NJ, the amount sent to the grid is recorded as banked. I pay a service fee of $2.78.