I actually did a research paper on solar power in the Austin area for my graduate cost accounting class.
The comparisons in the article aren't entirely accurate as to the costs.
Solar power tends to make electricity at the time of the day when it is most expensive to make electricity, i.e. peak power.
This means that you can't really use the base rate 3.5 cents per kw/hour to really do a valid cost comparison.
During most hours of the day, the cheapest form of electricity is used, i.e. generally coal, or hydro if available (not avail in austin area, so we tend to get our power from coal)
During peak hours, more expensive stand-by generators like gas-fired plants are ramped up and put into action to provide the extra power.
So the 16 cent per KWh solar power would not quite be replacing 3 cent per KWh, power, but more likely be replacing natural gas at 10 to 12 cents per KWh, if my memory serves. I am not to sure about that gas cost, tho'. It does fluctuate a lot, and it was a few years ago that I did the paper, so I don't have much confidence in that.
The benefit to putting in such a solar plant is mainly to shield the utility from future fuel cost swings in the upward direction.
I will 100% guarantee you that fuel costs, both coal and gas, will get vastly more expensive 10 years down the line, quite possibly as soon as about 5 years from now. If you want I can go into great length about this.
This might not seem like the best idea for right now, but having this thing either coming right online about then, or under construction by then will be a godsend.
I haven't seen the exact proposal for this, and there are several types of solar power (thermal, photovoltaic, etc), so it is probably quite possible that a much smaller scale plant can be built and scaled up.
That is one of the other benefits of solar power is its' scalability. One can always easily add another row of mirrors/cells to increase capacity as demand rises.
All in all, don't dismiss this project off the bat as an envirowhacko idea. It does make a certain amount of economic sense, and more so than this particular article might suggest.
One thing that you want to keep in mind is that Austin MUST increase its electrical generating capacity anyways.
The cost of a NEW coal plant or a NEW gas plant will end up costing more than the 3 cents per kwh as well. If you want to compare costs, the 3 cent figure given here is not the right cost to use.