Energy source of the future?

Newbie First Class Joined: Jan 26, 2010 Posts: 44

This is a topic I'm really quite interested in, and last semester I finished a (somewhat) major research project concerning it. I took the position that we should try to meet 70-80% of the world's energy needs from nuclear fission by (edit: 2050), but I was wondering if I could maybe figure out the general opinion of the board?

I'm hoping maybe we could get a nice sociable discussion going on this. As said, I'm primarily knowledgeable with nuclear, but I still have Google for everything else... Anyhow, mostly what I know about other sources are the negatives, since primarily that was what I was focusing on.

Thoughts? I'll [try] to stick close to this thread, but I'll probably fail.

Confident Learner Joined: Jul 28, 2009 Posts: 98

Based on what I have read, solar and wind technology would have to dramatically improve before they would be viable sources of the bulk of our energy needs. In addition storage and delivery technology would need to improve as well to prevent energy disruptions. As you know we currently make use of massive amounts of energy coming almost entirely from fossil fuels. If we take climate change seriously and want to incorporate renewable energy sources to keep CO2 concentrations below 450 ppm we would need to do the following according to engineer Saul Griffith:

Quote:

“Two terawatts of photovoltaic would require installing 100 square meters of 15-percent-efficient solar cells every second, second after second, for the next 25 years. (That’s about 1,200 square miles of solar cells a year, times 25 equals 30,000 square miles of photovoltaic cells.) Two terawatts of solar thermal? If it’s 30 percent efficient all told, we’ll need 50 square meters of highly reflective mirrors every second. (Some 600 square miles a year, times 25.) Half a terawatt of biofuels? Something like one Olympic swimming pools of genetically engineered algae, installed every second. (About 15,250 square miles a year, times 25.) Two terawatts of wind? That’s a 300-foot-diameter wind turbine every 5 minutes. (Install 105,000 turbines a year in good wind locations, times 25.) Two terawatts of geothermal? Build 3 100-megawatt steam turbines every day-1,095 a year, times 25. Three terawatts of new nuclear? That’s a 3-reactor, 3-gigawatt plant every week-52 a year, times 25.”

In other words, the land area dedicated to renewable energy (”Renewistan”) would occupy a space about the size of Australia to keep the carbon dioxide level at 450 ppm. To get to Hanson’s goal of 350 ppm of carbon dioxide, fossil fuel burning would have to be cut to ZERO, which means another 3 terawatts would have to come from renewables, expanding the size of Renewistan further by 26 percent.

I agree with you that the primary source of energy in the foreseeable future will have to come from nuclear power, but if the information above is accurate meeting 70- 80% of the worlds energy needs would require building a hell of a lot of nuclear power plants.

Newbie First Class Joined: Jan 26, 2010 Posts: 44

A bit dated - 1990 - but an excellent and expansive resource:
http://www.phyast.pitt.edu/~blc/book/

Agreed. While "green" sources would actually be the most aesthetic choice to me, I can't see us being able to utilize them except as power sources in remote places like Hawaii where power line distribution from a central plant would be impractical. I would be willing to reconsider them when their efficiencies breach 60%. Another critical failure is that since electricity can't be stored in the grid, an average home would have to purchase batteries priced at $6,000 (1990 price) every two years for periods where the intermittent renewable sources are not producing.

I don't have a citation for this, but I've heard that the increased carbon levels in the atmosphere has contributed to more prolific flora worldwide where other factors don't negatively contribute. Anyone?

And 70-80% does not mean much in the way of new extra capacity. There will obviously be a moderate worldwide usage increase by 2050 due to population growth and development, but it is looked at that that amount will probably be mitigated by an increase in efficiency in all aspects of energy usage. I'm talking about market share in the percentage given. Over the course of time, all power plants live out their lifespan and need to be completely replace. I'm of the opinion that all replacement plants be nuclear.

The amount of fuel required and waste contributed really isn't that much of a problem. In the link above, Cohen explains how there are potentially billions of years worth of uranium that can be extracted from seawater. Another thing is that uranium isn't the only profitably fissionable material, and I've been growing to be fonder of thorium as I've read more about it. Also, new plant designs will be more efficient and safer.

Blah, blah, blah - I could talk on this topic easily for 34 pages (That's how long my report was, and I was still leaving out things), and I'd rather respond to some proponents of other fuel sources if they'd like to have discussion, or those who believe they hold legitimate concerns over the safety of the nuclear industry.

Posted: Thu Feb 04, 2010 1:13 am

Ahh wind turbines!! (any Sim City 3k veterans here?)

Thought this might be interesting...

BBC wrote:

A major hurdle to producing fusion energy using lasers has been swept aside, results in a new report show.

The controlled fusion of atoms - creating conditions like those in our Sun - has long been touted as a possible revolutionary energy source.

However, there have been doubts about the use of powerful lasers for fusion energy because the "plasma" they create could interrupt the fusion.

An article in Science showed the plasma is far less of a problem than expected.

http://news.bbc.co.uk/2/hi/science/nature/8485669.stm

Posted: Thu Feb 04, 2010 7:19 pm

I'm betting we'll figure out fussion in less then 50 years. I'm also fond of thermal gradient technology and large scale solar, perhaps space based solar. There are certainly many viable possibilities, and hesitantly I agree that many sources will be necessary unless we can curb our insane population growth. Carbon fuels are a dead end in perhaps more ways then one.

Posted: Thu Feb 04, 2010 7:23 pm

invixxtus wrote:

In addition storage and delivery technology would need to improve as well to prevent energy disruptions.

Not only disruptions, but most of the current grids are extremely inefficient. Fuel cell technology could possibly be an answer with piped hydrogen as a fuel source. Either way, there will be a tremendous amount of infrastructure work.

Newbie First Class Joined: Jan 26, 2010 Posts: 44

Mhm, I had heard of that laser fusion device - I think in Scientific American first? All I remember is that the magazine had a nice pretty chart of the whole process.

And yes, the current transmission wire network pretty much needs to be scrapped. 10% efficient... woot. Last I heard, the best super conductors at the moment were an alloy of mercury, thallium, barium and some other elements with a critical temperature of 198K?

Wind turbines in SC 3000... yeah, I do well remember those. But nowadays they just put out a pittance of electricity and kill a few birds. (Hopefully primarily seagulls)

MockingGods:
Have they decreased the fracturing rate of x-ray energy transfer? Last I knew it still wasn't focused enough to permit decent transfer success. Has something changed? (I'm talking about your space-based solar suggestion)

Also, are you figuring that the hydrogen, since it doesn't occur naturally, should be processed using nuclear power? I figure that would be a good use of the excess waste heat from the fission process instead of just dumping it into a heat sink.

On thermal gradient, I know there is a tremendous amount of energy potentially available through it and it's a passive technology, but could you perhaps give the 5 second explanation of it? I know currently it could be used as a minor base load tech and the patent for it was pulled something around 30 years ago, but does it deserve more attention than I've given it?

In other news... I was talking to my drafting instructor today, and somehow or another Chernobyl came up, and he actually got remarkably upset over it. For those who were actually alive back then, do you see that as normal behavior in people when Chernobyl comes up in conversation with some people? I spent a good three pages discussing Chernobyl with a bit a dialogue on safety features on Western reactors. I would hate to have missed something that would have drastically changed my opinion.

Posted: Fri Feb 05, 2010 3:58 am

Syrtd wrote:

Have they decreased the fracturing rate of x-ray energy transfer? Last I knew it still wasn't focused enough to permit decent transfer success. Has something changed? (I'm talking about your space-based solar suggestion)

The latest tech I've seen was using microwaves to transfer and not x-rays. Seems promising. I heard a rumor that a power company in CA is actually investing in this.

Quote:

Also, are you figuring that the hydrogen, since it doesn't occur naturally, should be processed using nuclear power? I figure that would be a good use of the excess waste heat from the fission process instead of just dumping it into a heat sink.

Any sound electrical source could be used. In my opinion piping hydrogen instead of transmitting electricity via power lines would be more efficient but would require a great deal of infrastructure work. Fuel cell technology is still not where it needs to be though.

Quote:

On thermal gradient, I know there is a tremendous amount of energy potentially available through it and it's a passive technology, but could you perhaps give the 5 second explanation of it? I know currently it could be used as a minor base load tech and the patent for it was pulled something around 30 years ago, but does it deserve more attention than I've given it?

The Aussies were building a large, solar-assisted thermal gradient plant, let me see if I can find a link. The hypothetical project I saw on the science channel several years ago involved building a very large tower (I believe it was several miles high). The temperature, being much warmer at the lower altitudes at the base of the tower would drive very high air pressure up through the tower, which it turn would be used to drive turbines. I'd imagine natural occurring objects. like mountains, could be used in the same fashion without building the large tower.

The Aussie Project

The solar assist is an excellent idea. Heating the air at the base of the tower should mean higher air velocity and improved output.

Newbie First Class Joined: Jan 26, 2010 Posts: 44

Definitely microwaves, sorry, but they're also the same thing, just a different frequency. Apparently I'm an idiot, have an inefficient memory and a lack of the life skill known as Googleing.

Does pumped hydrogen look powerful enough to afford both the initial processing energy and the amount required to run (as I would see it) fuel cells along the way that provide the KE for the pumping? Also, being as hydrogen is highly flammable, it presents a real risk in its use and, though I'm loathe to mention it, the risk of intentional sabotage is indeed real. That much infrastructure would require an impractical amount of security to defend, so the pipes would be nearing completely vulnerable. (I still support the idea, however)

I think it's Solaren Corp that is proposing the current space solar power system in Cali, something after 2015 or so. I think the Japanese have something going on as well.

I'm well aware the middle paragraph makes me look like an idiot... but MG already quoted me, so it stays

Posted: Sat Feb 06, 2010 2:09 am

Quote:

Does pumped hydrogen look powerful enough to afford both the initial processing energy and the amount required to run (as I would see it) fuel cells along the way that provide the KE for the pumping?

I'm under the impression (I could be wrong) that using electrolysis (depending on the electrolyte) to extract hydrogen from water is very efficient and the energy loss upon reconverting through fuel cells is minimal. One must consider that a very high percentage of the energy received by the end user in current line transmission systems is lost. Depending on transmission length, loss can be in excess of 50 percent. I would highly doubt the energy required to pump and convert hydrogen would be any where near this.

There's another possible advantage with using a hydrogen system. The gas could be stored in tanks on sight as a back up power medium, pretty much eliminating power outages, and it would completely eliminate surge and brown out scenarios.

Quote:

Also, being as hydrogen is highly flammable, it presents a real risk in its use and, though I'm loathe to mention it, the risk of intentional sabotage is indeed real. That much infrastructure would require an impractical amount of security to defend, so the pipes would be nearing completely vulnerable. (I still support the idea, however)

Hydrogen is no more dangerous (and probably no more difficult) to pipe then natural gas, perhaps even less so, and certainly far less dangerous then oil or other liquid sources. Natural gas delivery technology should offer comparable systems.

Quote:

I think it's Solaren Corp that is proposing the current space solar power system in Cali, something after 2015 or so. I think the Japanese have something going on as well.

Our biggest hurdle is energy production. Fossil fuels will soon be a relic of the past. In my opinion, hydrogen offers the best medium as a fuel source because it's plentiful in its bound water form.

Newbie First Class Joined: Jan 26, 2010 Posts: 44

I guess all I have to offer is: True.

Though electrolysis isn't quite good enough to be called 'quite' efficient. Still pretty darn tootin' good.

Something that made me give someone a blank stare: Today, someone made a comment to me that perhaps the loss of energy via wire transmission could be a major factor in global warming.

And again I had a stupid moment. Hydrogen would just be trucked on site and stored in a similar container to propane pigs. Yup, that makes more sense than what was going through my head. Plus it would get rid of most of those wires, which would make me happy, since there is a spot where I should be able to get absolutely excellent sunset photos, but there's a power line that always shows up... Plus it would limit a little the deforestation, since all those perfect poles aren't needed. (Might get lumber back down to a manageable price - I know it took 50 years to make, but why is it so expensive?)

Just Arrived Joined: Jun 30, 2010 Posts: 2

I see Nuclear Fission as a future energy source. But, care should be atken. With Nuclear plants there is a finite amount of long lived radioactive material that remains if you reprocess the spent fuel. A poorly designed reactor (for example: Chernobyl) can result in significant contamination escaping, but not enough to contaminate the entire world.

Posted: Wed Jun 30, 2010 8:18 pm

maxdakota wrote:

I see Nuclear Fission as a future energy source. But, care should be atken. With Nuclear plants there is a finite amount of long lived radioactive material that remains if you reprocess the spent fuel. A poorly designed reactor (for example: Chernobyl) can result in significant contamination escaping, but not enough to contaminate the entire world.

I see the potential hazards of fission as less then the more obvious hazards of fossil fuels. However, putting a strong effort into fusion seems prudent, given the somewhat limited nature of fission fuels and their much higher potential danger. If we crack fusion, and I'm fairly confident we will, as long as the technology isn't suppressed to prop up the fossil fuel industry, it will quickly replace everything else.

Posted: Fri Apr 29, 2011 7:31 pm

Fossil fuels, massive solar farms (50 sq. miles = 1 typical coal or nuclear plant), Primeval forests of giant turbines (1300 super-size turbines = one plant) Massive farms and transportation networks to burn biomass or some other bio process to produce fuel adds to the already massive and destructive process of agriculture....all that really sucks.

We need massive trees and healthy phytoplankton to soak up carbon, as the ecology that created the atmosphere and environmental stability we want used exactly that system (requiring no outside influence). We can't do that by blanketing the surface of the planet with infrastructure. The only tech we have that is compact enough is fission. There really is nothing else, and nothing else currently imagined (this century) meets more of the needs with as little impact.

Let's face it: a large part of the problem with fission is public ignorance. Uninformed and unsophisticated opinions shift according to what that person feels is in their best interest at that moment, so public opinion will come around...no matter what they say now...when they start thinking that their social status will be declining. Oh, freezing, starving, or lacking transportation or a place to live decently will be important too, but status is what keeps the SUV's out there, right?

On the public opinion question, and the primary strawman in the nuclear debate, how do you folks feel about reprocessing spent fissiles?

Personally, I find that several scenarios of planning and development could easily bypass the worries about breeder reactors, having "bomb-making" material being produced and all that. We have gone the swords to plowshares approach for a long time now. If fuel is re-processed and pretty much instantly installed as an active pile in a plant, I just don't see much possibility of someone grabbing some material, going through all the process of developing a weapon and then fielding it by time persons offended by this activity take action on the perpetrators. Build Modular standardized Nukes (GO CHINA!) with modern designs I say.

Oh, BTW...all activities that promote heat retention or generation promote global warming (or should I say the fine balance of the carbon release/absorption system in the ecology). Transmission wire loss means you need to burn more fuel...but it is the burning of fuel that makes the effect happen, not the particulars of how efficient the waste/work ratio is.

Art
-P.S. I'm baaaaack !


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