Hi wylie,
This is the reason why solar hasn't taken off.
Even at a risk free, unleveraged 5% p.a. bank deposit rate, you could have preserved your 12.5K capital and received $ 156 in interest for the 90 days.
Obviously, exposing the same amount of capital to a prudent amount of risk and a sensible leverage would see the returns easily outperform the solar panel returns.
I understand people purchase these for the feel good factor, and that's great, but it certainly doesn't stack up economically to buy solar panels.
Unfortunately, everyone who buys a solar system tries in vain to justify to everyone who will listen that it is a good move from a money perspective. Nothing could be further from the truth.
...and that's in year 1.
In 15 years time when the system is stuffed / rusted / cracked / conks out and your capital has gone and you need to inject further amounts of capital to replace it, that is when the solar industry is really exposed as a greeny feel good thing, and nothing more.
Everyone looks at the lowered opex, and deliberately ignores both the opportunity cost of the capex and the large back end capex required to continue having slightly lower opex charges.
For it to work, supply charges will need to come down dramatically, as well as installation and commissioning costs. With Australian labour components in most of those 3 areas, I won't hold my breath for any major downward movements.....and hence the solar industry will be a dead duck for a good while yet.