Have these new designs improved on water usage problems [1]?
Although I agree about the closure of coal plants, it seems nuclear still has water usage issues (cooling needs) and given the upcoming fresh-water crisis [2], wouldn't solar be a better bet?
While there may be a fresh-water crisis on a global scale, that doesn't mean there is a shortage everywhere. There are lots of places where there are ample water supplies, and use of the water there doesn't really effect water availability in places where it's in short supply.
Also, you can cool a nuclear reactor with ocean water. Seabrook Station in NH is cooled this way, as are other reactors located on ocean coasts, presumably.
"In a December 26, 2007, opinion column in the The Atlanta Journal-Constitution, Nolan Hertel, a professor of nuclear and radiological engineering at Georgia Tech, wrote, "... nuclear reactors can be used ... to produce large amounts of potable water. The process is already in use in a number of places around the world, from India to Japan and Russia. Eight nuclear reactors coupled to desalination plants are operating in Japan alone ... nuclear desalination plants could be a source of large amounts of potable water transported by pipelines hundreds of miles inland..."[12]
A typical aircraft carrier in the U.S. military uses nuclear power to desalinate 400,000 US gallons (1,500,000 l; 330,000 imp gal) of water per day.[14]
Also, you can cool a nuclear reactor with ocean water. Seabrook Station in NH is cooled this way, as are other reactors located on ocean coasts, presumably.
Progress Energy's Brunswick Nuclear Plant[1] in Southport, NC takes brackish water from near the mouth of the Cape Fear River as it's source of cooling water, then discharges it through a canal back into the Atlantic Ocean.
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.
Is that price per watt of peak power production, or per watt of average power? Solar tends to have a fairly low capacity factor, which is important to include in economics calculations.
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.
Those are valid numbers as long as solar is backed up by fossil fuels or nuclear, but if you want use solar for most of your electric power, you have to take energy storage into account. That's a lot more expensive.
Although I agree about the closure of coal plants, it seems nuclear still has water usage issues (cooling needs) and given the upcoming fresh-water crisis [2], wouldn't solar be a better bet?
[1] http://www.ucsusa.org/nuclear_power/nuclear_power_technology...
[2] http://www.ncbi.nlm.nih.gov/pubmed/12291371