I have some experience with solar energy at the small scale (1-2 kwh arrays) and I can say that at the consumer level, the cost for a solar array is now dropping to roughly $0.50/watt. It's still nowhere near the scale/cost of nuclear/coal but it's definitely more feasible than it was ten years ago.

Using the figure of $0.50/watt, to construct a 50MW plant would cost $25 million for the panels alone; bring in the infrastructure, mounting, and remember that the panels lose roughly 10% of their capacity every ten years. Plus account for cloudy days (not as much of an issue in, say, Arizona) and you start to realize that solar isn't a very viable option.

It works really well at the consumer/personal/business level but fails horribly at large, centralized setups. For those about to mention the `good sunlight' requirement, I will provide some refutation for that: my panels are located such that there is a good 30-degree angle to the east the sun has to peak before the light reaches them. The only time that power becomes an issue is the three weeks either side of the winter solstice; at which point I have to start watching my power consumption and regulating computer use etc.

I've assembled the array (roughly 1.5KWh) over the past ten years or so; the cost has been small considering what the equivalent would have been to purchase electricity from the power grid.

I have rambled on for quite a while here, for which I apologize. I guess the TL;DR version is: I don't think solar is feasible at large scale, but it seems to be at a small scale in my own experience.

I'm not well informed, but according to John Quiggin[1], yes:

(PV is photovoltaics)

    the cost of PV has already fallen well below that of nuclear and
    is set to fall further. The average retail price of solar cells as
    monitored by the Solarbuzz group fell from $3.50/watt to $2.43/watt
    over the course of the year, and a decline to prices below $2.00/watt
    seems inevitable. For large-scale installations, prices below
    $1.00/watt are now common. In some locations, PV has reached
    grid parity, the cost at which it is competitive with coal or gas-fired
    generation. More generally, it is now evident that, given a carbon
    price of $50/ton, which would raise the price of coal-fired power by
    5c/kWh, solar PV will be cost-competitive in most locations.

http://nationalinterest.org/commentary/the-end-the-nuclear-r...

[1]: https://en.wikipedia.org/wiki/John_Quiggin

No.