Solar Panels we are talking about here should not be confused with Solar panels for Hot water or heat.
Having uses photo electric solar panels myself now for over 20 years I have seen a large advancement in these, much of it coming since governments embraced the technology.
It's true the cost of these have come down an one can get a panel for less then 1/3 the price it may have cost just 10 years ago.
Although cost is a factor in the improvements supply and demand is more so.
The same physical size panel will now produce almost double the power output of a 10 year old panel and that's no just because of age.
Advancements are not only in the Panels but in the other electrical components required, Inverters and charge controllers which are the key elements to these working well have also improved.
These now work at over 90% efficiency.
Storage is the one area that is lagging, however improvements are being made in this area as well.
This is driven by the cell phone and tablet market and the desire for longer run time between charges
I also feel much safer with my neighbor installing a solar array then splitting atoms.