The other top HN story is about a 1180 megawatt nuclear plant, which outputs about twice the power in a fraction of the space:
As a comparison to coal, 3 million or more tons of coal is required per year for the equivalent amount of power.
Rhetorical question. Neither.
A 1 GW reactor needs 200 tons (Mg) of unenriched U3O8 (237.5 kmol). That is typically 0.72% U-235, and needs to be enriched to 3.5-5% (low-enriched uranium) for fission fuel, which is usually UO2.
So the 237.5 kmol of U3O8 contains 5.130 kmol of U-235, which can make 102.6 kmol of UO2 (5% U-235), with a total mass of 27.7 tons. That leaves 609.9 kmol of leftover (depleted) U-238, or 145.2 tons. That typically goes into armor-penetrating bullets and artillery slugs.
That's the downstream side. One ton of U3O8 might mean up to 999 tons of mine tailings--which are less radioactive than the natural rock, as the U-235 has been removed from them. Nevertheless, they may also contain toxic heavy metals that have never before been exposed to weathering.
So let's say up to 199800 tons of tailings that require some additional processing due to potentially toxic runoff. Coal mining also has the same problem with tailings, but coal-mining tailings are often a viscous, corrosive slurry.
200000 tons sounds like a lot of waste, until you compare it to the coal plant.
The observation is meant for solar in general. In Europe, the US, and Japan, for example, many people are pro-solar, which is good. However, it appears that nuclear is really needed if want to greatly reduce our dependence on fossil fuels. Coal is still used for 40% of electricity generation in the US. It's 80% in China, which uses even more electricity.
That's true now, but both the Democrats and the Republicans have committed to reducing that number to 0% now that the US is one of the biggest producers of natural gas.
+ high quality heat aka hot salt -> thermodynamic machine -> high quality shaft power + low quality waste heat.
https://upload.wikimedia.org/wikipedia/commons/e/ed/Fullneed...
Rooftop solar generally uses ~0 new space, and there is quite some reason to believe that prices will continue to drop so that people in sunny regions will install it simply to save money.
It probably isn't the solution to industrial power demand, the local mill here uses more power than the rest of the county, but so what?
How much space does it take, compared to a hydro plant of equivalent power? Hydro is also relatively clean, and is also known for taking massive amounts of space.
Hydro is the most environmentally destructive source of power. It ruins more natural habitat than strip mining coal, clearcutting forests, solar PV in virgin land, or any other kind of generation. And the river bottoms and canyons it destroys are among the most biodiverse habitats in the world before their destruction.
In 2013 the plant generated a record 98.6 TWh,
supplying approximately 75% of the electricity
consumed by Paraguay and 17% of that consumed
by Brazil.
It's nice to sit in ivory towers and criticize. In the real world, many many people's lives are made much easier and more productive by harnessing this inexpensive hydro power.
You want to solve some real problems in Brazil, figure out how to stop the destruction of the Amazon rain forest. That, there, is a world scale tragedy. Not so the beautiful Itaipu Dam, which I've toured, and which helps so many Brazilians.
https://www.newscientist.com/article/dn7046-hydroelectric-po...
http://www.iea.org/stats/WebGraphs/MOROCCO2.pdf
Take the recent solar project, Noor I, that's launching within a month. Its production is about 370GWH per year, hydro currently does something close to 1900 GWH.
http://thinkprogress.org/climate/2015/05/11/3657220/solaroad...
And a road built from glass? What happens in winter with ice forming? That's not going to go well.
You will lose some area to potholes. That's just another reason not to use the expensive, glass-covered cells.