[Scotty]

really i think the best way to deal with any/all nuclear waste is, pending orbital elevator, shoot it at like the sun/moon/something.
ALTHOUGH if there's water on the moon, though, it would not be that good a target

I used to agree, until someone raised the statistical certainty of future accidents during launch or ascent. The consequences of even one such accident involving a spacecraft laden with nuclear waste would be disastrous, to say the least.

I'm not opposed to nuclear power, but the question of what to do with the waste is kind of a huge problem.

With some more R&D I'm willing to bet that waste (spent fuel rods) can be minimized and a safety massively increased.

Waste is a problem that has been solved technically, the problem is politics. It isn't nearly as dangerous as it is made out to be by anti-nuke propaganda.

Yes.  See my post, and google those terms.  Then laugh/weep at/for those in Congress.

[SpardaSon21]

Isn't it also possible to recycle nuclear waste and make it usable as fuel again?

[IceFire]

Here's something else to think about.

You can't just say, "OK, changing to this power source is a good and wonderful thing."  It HAS to be economically viable.

Also, hydrogen is a red herring.  It takes something like 58% of the energy you get back from burning the hydrogen to crack more hydrogen from water, the most likely source of the copious amounts of hydrogen.

True that it does have to be economically viable, however, in my mind there are break even points where a technology goes from being impractical to viable and economically beneficial.  There was huge impetus to develop nuclear technology, primarily as a weapon system at first, and none of that was economically viable but it was justified during wartime spending.  I'm sure that hydrogen and other technologies will get better given enough time, research and money.

[Nuke]

its also kinda important to note that what was considered nuclear waste in the 60s can now be considered useable fuel in some modern reactors. by the time 10th generation reactors come into being, what we consider waste now will once again be considered nuclear fuel. on the other hand not all nuclear waste is spent fuel, a lot of it is contaminated materials, tools, hardware and equipment. none the less i think temporary underground storage is a good idea. with continued r&d we might one day have a use for what we consider spent fuel and other waste.

[Slasher]

Isn't it also possible to recycle nuclear waste and make it usable as fuel again?

The science behind fast breeder reactors indicates this is the case.  Fissionable material goes in, fissionable material comes out.  Optimistically, we could extend the world's nuclear fuel supply indefinitely.  Breeder reactors or not, fission is going to be the bedrock of future electricity production.  It would be nice if we had more time to work out some of the science and engineering behind next generation reactors, but we really should have thought about that in an age where U.S. oil production wasn't in decline, the number of new oil fields discovered every year wasn't diminishing, and our consumption of fossil fuels did not continue its exponential rise.

Despite their critics, wind and solar will likely have their place too, but as was mentioned, they will mostly be confined to areas where their advantages arrest their drawbacks.  Pump storage facilities are feasible in areas where the terrain/hydrology permits them.  You can't plug them in to just any wind farm, unfortunately.  From what I've read, off-shore wind farms offer more power (in terms of kilowatt-hours per m²) than do land based ones, but they also add some new problems to the mix in addition to inheriting most of the old ones.  Those new vertical-axis wind turbines look interesting at least.

Multi-junction photovoltaics are reportedly able to capture a much broader spectrum of the sun's light, breaking the 10-15% efficiency range of solar cells that has been the norm for the past thirty years or so.  Right now their developers are claiming efficiency to the tune of 30-40%, and I feel like I'm making a grotesque understatement just by saying that is an improvement.  But in addition to the traditional silicon wafers, current multi-junction cells use indium and gallium, again raising concerns of essential material shortages.  While there's always room for improvement, I have a hard time imagining how this technology could take off on a mass production scale right now.

As for solar - sorry, but photovoltaic cells are currently damaging to the environment, because it takes so much energy to make them. A few years ago, they took more energy to make than they would ever generate in their useful life. While this has improved, they're still pretty terrible.

Solar/Wind Plants = fail. It costs the environment more to produce them than it gives to save the enviroment (I hope the sentence is clear)

All my research indicates the amount of kWh expended on the production of photovoltaics, solar thermal facilities, and wind turbines is exceeded by the amount they produce.  The carbon dioxide that goes into the life-cycle cost (LCC) of photovoltaics, solar thermal plants, and wind turbines is certainly not pretty, nor are some of the ugly byproducts of the manufacturing processes.  Still, lot of the carbon output involved is directly attributable to the fossil fuel burning power plants needed to make these things.  And when you compare the LCC of PV and wind turbines with that of coal-firing plants there isn't much of a competition to be had.  Obviously location and scale matter a lot in these instances, but making sweeping generalizations like the two above is...obtuse, to say the least.  

Now with nuclear reactors, I'm not so sure.  If you were to compare the number of grams of carbon dioxide emitted per kilowatt hour produced during the life-cycle of a nuclear power plant to that of a photovoltaic plant, even one in a desert environment, I'm guessing it's a similar no-competition race in @t0mz favor.  

Again, it's worth remembering that improvements in technology and efficiency may further reduce carbon dioxide emissions and industrial waste during the construction and production of solar cells, nuclear reactors/power plants, wind turbines, etc.  To me, it seems like a lot of science has been done but not a lot of it has been acted on yet.  

[Tomo]

I was very specific in that statement. Photovoltaics. No generalisation there at all, as there are very few ways to make photovoltaic cells, and they *all* require melting of extremely pure silicon. They are actually very similar to TFT LCD screens.
Most of them also require very a good glass substrate, others a plastic one.

Recent improvements in output and manufacturing techniques (last 5 years or so) have finally made them energy-gaining, but nowhere near as good as other generating systems.

Solar thermal is feasible in some locations, sometimes more efficient than PV would be (particularly in big plants) and *always* cheaper to build.

You can actually build a pretty good water heater in most climates using nothing more than a small pump, copper pipework, sheet metal and paint, which dramatically reduces the usage of heating fuels (gas/oil/electric).

[Kosh]

he science behind fast breeder reactors indicates this is the case.

I think he was referring to waste reprocessing, which is done in Europe and Russia, although oddly enough it is banned in the US. In spent fuel rods most of the waste is actually plutonium, which can be extracted in the reprocessing cycle and reused.

[Slasher]

We are going to need to repeal those laws and invest in the infrastructure necessary for waste reprocessing in that case.  Hopefully in the near future the government will start funneling more money in that direction.

Also for anyone who still thinks photovoltaic cells require disproportionate amounts of energy to make and doubt their EROEI relative to wind/hydroelectric/biomass/nuclear might want to read these:

Environmental Impacts of Crystalline Silicon. Photovoltaic Module Production
Emissions from Photovoltaic Life Cycles
The solar photovoltaics wedge: pathways for growth and potential carbon mitigation in the US

As these articles note, if ramped up, photovoltaic production would add a small but by no means irrelevant amount of carbon dioxide to the atmosphere.  

One unfortunate thing I noted was that at least one of these seems to advocate for cadmium telluride (sp?) cells which aren't necessarily any "greener" than crystalline silicon.  My understanding is that thin film CdTe still offers a better deal in terms of grams Cd per kWh than household batteries, for what it's worth.  

A lot of this wouldn't matter if U.S. public opinion wasn't so acidic towards fission.

[fener]

Some very useful blog posts on these issues:

Thinking critically about sustainable energy (TCASE) 1: Prologue
TCASE 2: Energy primer
TCASE 3: The energy demand equation to 2050
TCASE 4: Energy system build rates and material inputs

Radiation – facts, fallacies and phobias
The Integral Fast Reactor – Summary for Policy Makers
Recent nuclear power cost estimates – separating fact from myth

Solar realities and transmission costs – addendum
Solar thermal questions
Remote solar PV vs small nuclear reactor – electricity cost comparison
Germany – crunched by the numbers

Does wind power reduce carbon emissions?
Wind and carbon emissions – Peter Lang responds

[Stormkeeper]

We need solar energy. Quick, construct orbital elevators to collect solar power!

[Liberator]

We need solar energy. Quick, construct orbital elevators to collect solar power!

Agreed.

Tho some of the heights suggested are kinda low, any truly stable orbital elevator/tether system is going to be anchored at both ends, one end in bedrock(prolly on the order or 1/2 deep or so) and the other end to an orbital platform in geosynchronous orbit at whatever altitude is deemed suitable, though 22,500 is the low limit I think.

[Stormkeeper]

Well, if we really want to get a respectable amount of solar energy, I think we need to collect it before it gets filtered out by our atmosphere.

[SpardaSon21]

But then how do we transfer it from outside the atmosphere to inside the atmosphere?  Its going to require a lot of very long power cables to do something like that.  Transmitting it in the form of some kind of radiation probably wouldn't be feasible.

[Stormkeeper]

Microwave. Collect it, then transfer it via microwaves to a collection point of some sort?

[SpardaSon21]

Isn't there some energy lost in transmission?

[Scotty]

That and the gigantic (figuratively) microwave beams slashing through the atmosphere.  Ever played Sim City 2000?

[Stormkeeper]

We could do it the 00 way. Though it seems extremely expensive and the elevators are rather brittle as structural integrity goes.

Basically, three large orbital elevators are terrestrial 'anchors' and serve as oversized wires to transmit the solar power back down to Earth. The elevators themselves are connected to each other with an orbital ring and are topped by massive solar collectors, though I'm not sure of the exact structure.

[SpardaSon21]

Sounds expensive and fragile.

[Stormkeeper]

Yeah, it is. In-universe, those things all have major military installations and presence.

[Mongoose]

And yet seem to be very prone to terrorist actions.