I see over on the NewScientist website that Obama gave a speech at MIT today regarding the "global race to develop clean energy", proclaiming that "the nation that wins this competition will be the nation that leads the global economy". I've read the thread in this forum titled "Power Sources Beyond Fusion", and I guess we can all agree with Mugaliens that "In reality, we're looking at:

1. Fission
2. Solar
3. Wind
4. Geothermal
5. Fusion

</endquote>

My question to the many top notch scientists at this site is, what in your opinion is the next most viable energy source of those five, or perhaps a different one?

I don't think a solution to our problems will come from a single energy source. I think the most viable solution is a multiple sources.

For example, several of these (solar, wind, geothermal) are very location dependent. Parts of the world where solar may be less attractive (such as Ohio), wind might be a better choice.

But I do think that fission, particularly with newer reactor designs, should be increasingly important (I'm unconvinced it will be, but that has to do with issues beyond the bounds of discussion on this board).

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

I would add a sixth: Efficiency.

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If they can get you asking the wrong questions, they don't have to worry about the answers.

Personally - I hope to see local (i.e. per-house) Wind & Solar - plus Nuclear (fission, transitioning to fusion) on the 'grid' as a top-up. The wind & solar for homes is too expensive at the moment, it needs to drop a LOT, but it will, given time.

Next most to what? It's unclear what the original question is asking.

Anyway, one notable omission from that list is hydro.

Hydro-electric power generation is, of course, real and may be part of a larger water management infrastructure that's important above and beyond just the power generation aspect of things.

Wave power may also be significant.

Tidal power may also be significant, and it's noteworthy because it's ultimately Moon powered rather than Sun powered.

Algae

Next most viable compared to what we have now, which is largely still hydrocarbon based -- right?

And I'm going to strongly agree with you IsaacKuo. I used to be an avid scuba diver in SoCal. Gravity, wind and waves combine to produce constant and strong back-and-forth surges (currents) offshore in the 10 - 30 foot below surface range. Hundreds (and thousands) of turbines offshore in those waters would provide a continual source of energy. I think another advantage of having those offshore turbines could be ease of plugging into the existing power grid, a definite consideration for any future clean power source.

The big question with near shore ocean power is how to keep operational costs low. All those battering waves and salt water are not friendly to hardware, so you have to consider ongoing maintenance and replacement costs.

I wonder if you could simply lay down a large pipe from the shore, with a bunch of one-way flap valves to gulp in water. This lets you put your turbine on the shore, above water, where it's easier to maintain/replace than if it's offshore, underwater.

[edit - added]

On second thought, it would make more sense for the pipe to "suck" water from the shore into the ocean. That is, the one way valves let water exhaust into the ocean. That way, the offshore pipe is more or less self cleaning, you just need to screen the intake pipe (which is conveniently accessible at the shore).

Wave powered marine turbines may be possible for near shore ocean power. There is much more energy to be extracted from wave and tide than can be provided from a pipe to suck water from the shore into the ocean.

Can anyone comment on nuclear reprocessing technology (i.e. breeder reactors)? I'm sure the politics surrounding the issue are relevent, but in this case I'm interested in viability for meeting energy needs.

I think the power systems we use over the next century or so will go in stages. At the moment, the top priority for power generation is eliminating Carbon emissions, which of course means shutting down Coal, Gas and Oil powered plants and converting vehicles to eclectic or renewable/sustainable biofuels (or better yet, get rid of most independent vehicles like cars and just move to mass transit).

Now I'm a Green, but unlike most of my Green colleagues I believe that we will have to use nuclear fission at least as a stop gap until we get fusion. I don't particularly like fission, but given the alternative (Global Warming) some nuclear waste and accidents will be a small price to pay. We've clearly got to use the whole range of renewables, as well as Fission to replace the hydrocarbon plants.

It will certainly have to be a diverse system and I'm sure different countries and areas will be getting power from very different sources. For a lot of less populated countries sources like Hydro (Norway), Geothermal (Iceland), Wind (Denmark) either already meet their needs or can in the near future. They're the lucky ones, with small populations and abundant renewables they're basically set. Then there are the countries with massive populations and not a proportionate amount of renewable power, like China, India, Germany, the UK and the US, for them renewables almost certainly will not be enough. They'll have to go the Nuclear route, but still use renewables where they can, hopefully they can get about a 50/50 mix of renewables and Fission.

Then there's ground based Solar power, although it probably won't be the primary source for most counties (Solar power is probably not great enough in the Northern Hemisphere, where most of the industrial countries are), it is likely to be used to augment generation along with the other renewables. The areas where Solar will really be useful will be in the hotter, dryer areas of the world, Africa (the Sahara being the biggest potential), the Middle-east, Australia, etc. In these areas solar should be the primary energy source, though probably augmented by others.

I'd say once we have all that done, which will probably take 50 years or more, we will have averted Global Warming and can then develop the next steps. In 50+ years time the two real futures of power will probably become available. Namely Nuclear Fusion and Space based Solar power. I think at that point we should totally abandon Fission and maybe some of the renewables that are somewhat environmentally damaging. Anyway, that's my opinion of the way ahead.

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The Sky is no longer the Limit

i've always felt that the base electrical load should be handled by things like nuclear, wind, solar, and hydro power plants with a certain percentage of overhead built in for sudden spikes in demand. then you have some gas/coal/garbage/whatever-is-cheap-and-will-burn plants to take up the slack when the power usage spikes at predictable times.
that frees up the oil for cars and other mobile things that need power and range.
yeah, there might be holes in my plan- but i don't claim to be an expert. it just makes sense to me.

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"blacker than the blackest black... times infinity."- Nathan Explosion
The.. Best.. Thread..Ever...

I think there isn't so much an energy crisis as there is a crisis of will. People are by nature lazy and selfish (generalization). I'm a big proponent of incentives. Incentives for recycling (perhaps as a deductible?), for using less electricity than the neighborhood average, and etc.

It's my opinion that giving the adults of today the incentive to do such actions will lead to a greater percentage of future children with such behaviors being second nature (by virtue of good parenting).

There is also the issue of internal conflict: pitting selfish desire (spurred by runaway capitalism) versus the necessity of behavioral change. Citizens of developed nations are told to buy, buy, buy, but no one in power will tell them conserve, conserve, conserve, because it is at odds with the methods of capitalism.

I think humanity would greatly benefit from some sort of steady state economy (instead of one based on growth), but with greatly increased governmental investment in the technology sector.

There is plenty of energy available and humanity would prosper if we were more united. With the proper technology employed, there is billions of years worth of fissionable material available.
http://www-formal.stanford.edu/jmc/progress/cohen.html

Kind of a rant and kind of all over the place, but...

my two cents,
M74

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I pray to no one.

That would be a perfectly reasonable position, ten or twenty years ago. But Emission reductions means getting rid of those oil burning cars too, you can't just switch oil from power plants to cars, the amount burned will still be the same.

But as for oil, consider this; it is one of the most versatile and useful materials known to man and almost everything around us has some element of petrochemicals in it, all Plastics, tools, houses, vehicles, even medical drugs. So why the hell are we burning it like there's no tomorrow? Even if GW wasn't an issue, Peak Oil still would be and we'll miss it when it's gone.

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The Sky is no longer the Limit

I agree. There is a place for solar, wind, geothermal, but they can't meet our needs alone. We need to invest now in fission reactors. The problem is that it's easy to scare people with them. There are solutions to both reactor design and extreme long term storage of nuclear waste.

A few points as I see it:

1. As Mike Alexander suggested, efficiency is the cheapest way to cut energy use and thereby CO2 emissions. This includes measures such as insulation, LED lights, smart grids and smart metering. A smarter grid, both on a large scale and small scale will allow more energy from intermittent sources to be used. For example hotwater systems and refrigerators and freezers can be used as "batteries" to store heat or "coldness" when electricity is cheap and switch off when it is expensive.

2. An important energy source left off the list in the OP is biomass. Biomass is important because it can be used in existing coal plants, providing an easy way of cutting CO2 emissions as all the carbon in biomass is absorbed from the atmosphere. Even a fairly low price on carbon such as what currently exists in the EU will result in a shift towards using biomass over coal. The larger an area's agricultural sector, the more important biomass is likely to be. It has a lot of potential in Australia, the US and many developing countries. It is not a perfect solution, but it does make use of existing fossil fuel infrastructure. Biogas can also be used to replace natural gas, as it is to a small extent in the EU.

3. Wind power is extremely viable, as evidenced by it's huge expansion in capacity over the past few years. My state gets almost 20% of its electricity from wind, on account of how it is cheaper than using natural gas.

4. Hydroelectricity will increase in importance with a price on carbon as it will result in many small scale hydroelectric schemes on existing irrigation dams becoming profitable. It's ability to provide peak power will make it very valuable. In developed countries, most large scale sites are already in use, but some will be and are being modified to provide greater peak generating capacity. One danger is that climate change will reduce rainfall in many temperate areas. Developed countries are unlikely to see large increases in hydroelectric generating capacity.

5. Geothermal, both conventional and unconventional (dry rock) have a lot of potential. Dry rock geothermal could be an important source of baseload power in the future, while some countries have huge amounts of untapped conventional geothermal power. For example, Indonesia apparently has enough potential geothermal resources to meet all its energy needs with a large amount left over for export.

6. Solar power has a lot of potential. Although it is still expensive at the moment compared to improving efficiency, coal, natural gas or wind, its cost has dropped dramatically and will most likely continue to do so. I expect that in under 15 years a large scale, point of use PV system, such as might be installed on a factory, warehouse or shopping centre, will be able to produce electricity at a lower cost than purchasing it from the grid in sunny areas. With a price on carbon this point will be reached even earlier.

7. The percentage of energy from nuclear power seems likely to shrink due to the high costs of building new plants and competition from other low emission energy sources. If a nuclear power plant can be built in a developed country that can compete with other energy sources in a free market, then this situation will be turned around. Some people think that the price of nuclear will drop in the near future. Currently, no company or consortium appears capable of building a nuclear power plant that can compete in a free electricty market and the costs of developing new reactors that may be cheaper are very high. This makes me think that we are unlikely to see a large drop in the cost of nuclear power soon.

This is true. The costs of nuclear have been made prohibitive by a public that is convinced that nuclear power is "evil". However, it has been shown that as fossil fuels run out, the alternatives to nuclear power aren't going to be sufficient to close the gap. We are going to need the nuclear option.

If nuclear remains more expensive than other options, why would people need it? Aren't they more likely to use the cheaper options and save some money? If the cost of building nuclear capacity averages $8,000 per kilowatt of average output and some combination of wind, solar, biomass and geothermal capacity averages $6,000 per kilowatt of average output then it seems likely people will forgo nuclear.

Communism has always been much more popular with people who haven't been subjected to it.

And a seventh: effectiveness.

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If I set the budget, we'd have Ares and more. Unfortunately, I don't set the budget, and Ares is just too expensive and too far out for us to accomplish our goals within the budget we were given.

If we halt the ISS, all versions of Ares, and transport Orion and Altair aboard DIRECTv3's Jupiter family of Shuttle-Derived Launch Vehicles, we just might make it back to the Moon by 2020.

Go look at France.

Remarkable. Which state is that?

Edit: I shouldn't make economic arguments. Meh.

If I had to pick, I'd choose wind, with solar a close second (though that may switch with better solar panels and the like). Fission has been well-established for a while, fusion remains a dream, and geothermal is simply too limited in scope. One that's not up there that has also some real potential is tidal power.

And, ditto for those who say that the best solution for future power needs is a diverse suite of energy sources.

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State

I'm sure your right about that, but I wasn't suggesting communism. I was implicitly suggesting the importance of regulation in capitalistic societies. I do think it is to humanity's benefit for children to be taught compassion and behaviors relevant to the care of the world at an early age.


M74

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I pray to no one.

I tend to agree with most of the posts-- and certainly nuclear technology has been given a lot of bad publicity---there are increasingly better designs; as well as newer technologies-- utilizing different isotopes than U or Pu.---namely hybrid-type nuclear technologies.

Univ of Texas

the link is just one of which I found recently...

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"The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir."
---Carl Sagan

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At night the stars put on a show for free (Carole King)

One Earth, One Sky - IYA 2009
All moderation in purple

South Australia. It will be about 20% by the end of the year. The amount of electricity produced by wind is expected to roughly double over the next six years. The grid can handle large amounts of wind power due to the large amount of gas generating capacity and the ability to export some electricity.

I would assume the (?) vast expanses of the "outback" lends itself to such an endeavor--

please tell me if climate alteration has anything to do with how the winds might have changed or are expected to possibly change in the next dozen or so years--- I read somewhere(?) that Australia has had its ecosystem changed in the last 10 to 20 years because of the "global" (?) problem.

cheers

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"The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir."
---Carl Sagan

Uh, that's the point. The other sources don't have the ability to make up the difference between what people consume if fossil fuels are taken out of the equation. Unless people choose to forgo some of the the things they currently take for granted, nuclear is going to be necessary.