View Full Version : Nuclear Fusion Energy

2004-May-23, 11:03 AM
Here is a news item on the site where the next prototype fusion reactor is possibly built.

I wonder if this method of energy production will ever work. It has been tested for decades and imo no significant results have been produced. How close is fusion energy to being realised, more to the point will this ever work?


2004-May-23, 11:44 AM
Originally posted by VanderL@May 23 2004, 11:03 AM
will this ever work?
I think it will work. The problems are large, but ITER will produce more than enough energy to run itself [by a modest margin]. This will be used to make refinements, and gain further knowledge about how to do it better and cheaper.

The next generation fusion reactor after ITER will be designed based on this, and it will probably be the prototype for the first generation of commercial reactors. I expect that these will go on-line starting about the year 2035 to 2040. I expect that they will generate about 10 to 20 GWatts each at a cost of about 2 dollars [2004 value] a watt [construction, operation, and decommision costs]. This is less than fission and solar costs, and more than what oil and coal currently cost [but that may change]. It is about equal to what wind costs.

2004-May-23, 06:46 PM
It has been tested for decades and imo no significant results have been produced.

Actually, there have been large advances in fusion technology. When fusion was first controlled, it took thousands of times more energy to sustain the reaction than what was produced. Today, it takes only about three times as much.

2004-May-23, 09:50 PM
Fusion works in the sun, but that is about all I can say for it. Fission will still probably be cheaper, due to reactor simplicity, even if they could get those giant doughnuts to put out more energy than they consume.

2004-May-24, 01:11 AM
I hear that Fusion generated energy will be too cheap to meter. :D

John L
2004-May-25, 02:22 PM
The whole purpose of ITER is to complete the necessary rearch into fusion reactor design so that commercial reactors can be constructed. I don't think there will be any more test reactors between ITER and commercial production unless someone has a better, cheaper, smaller way of doing it. I've seen one that replaces the huge torus with a single small sphere, but that design isn't as far as ITER.

2004-May-27, 06:11 AM
I have a question about the projected cost of fusion energy compared to solar which antoniseb stated:
I expect that they will generate about 10 to 20 GWatts each at a cost of about 2 dollars [2004 value] a watt [construction, operation, and decommision costs]. This is less than fission and solar costs

Pardon my wordiness, I just want to be understood clearly.

A conventional house comes complete with bathrooms and a kitchen. Assume the median price of a house is $125,000 . With regards to real estate purchases, I never hear people ask, "And how much is the house if you include the bathrooms?", or, "How much extra is the kitchen?".

That's because they are included in the purchase price.

Now, I have designed and built and am replicating homes for the commercial market which actually exceed code and have a higher quality of construction compared to a conventional house with the same amount of square feet. I can produce this design and sell it for a lower price than a conventional house. I am including a Solar energy collection system, inverter, power control system and batteries in the purchase price of the house. Again, the entire, complete system, the house with bathrooms, kitchen and Solar energy system is less than the median price of $125,000 , so no additional funds are required for the Solar energy system.

Am I allowed, in this situation, to say that the cost of the solar produced energy in my system is free? And therefore, wouldn't "free" be less than all the other options suggested, including Fusion?

2004-May-27, 10:51 AM
Originally posted by Tom2Mars@May 27 2004, 06:11 AM
Am I allowed, in this situation, to say that the cost of the solar produced energy in my system is free?
I was speaking of the cost of producing electricity with of Solar-Electric panels. I imagine that these could be built more cheaply if the operation is scaled up, but if you assume a twenty-year life of the panel, and a normal amount of maintenance, they currently come in as a high price for electricity. Personally, I'd prefer them to be the cheapest route, since aside for the mess from manufacturing them, they are a pretty green power source.

You build passive solar houses? Great! I'm all for that!

2004-May-27, 07:54 PM
Antoniseb, Thanks! You made a correct observation about the cost-benefit of PV's and the less than optimal production process(messy). I liked your comment so much that I put the quote into the Moon or Mars topic at this spot in the Human Spaceflight catagory (http://www.universetoday.com/forum/index.php?showtopic=3297&st=30&#entry29557)

I have started kidding around with people that my Solar Panels are actually performing the final step in converting Fusion generated energy into heat and electricity (I'm sucking heat off the backs of the panels for hot water which also reduces the panel temperature and increases the electrical output by 15%. The panels are 14 years old now so I can experiment with them.).

Anyway, I mention that my Fusion generator is 94 million miles away, and even though it seems far enough, if you stand in front of it too long, you get a "radiation burn". When one person refused to laugh, I threatened to burn him with my Fusion heated garden hose water, then they got the point.

So, to make a long story(usual for me!) short, I guess I'm using Fusion generated power right now. :P

2004-May-27, 08:03 PM
T2M, I would like to read a bit more about your manufacturing process and the house you design. Would you email me a link I can go to?

2004-May-28, 12:40 AM
When you think about it...solar power really IS a form of fusion power, as it comes from the sun. The same could be said about any form of energy on Earth.

I think that a sustainable fusion reaction that produces significantly more energy than it consumes is indeed possible. The ITER is a step in the right direction.

2004-May-28, 02:06 AM
I've been watching new developments, and I'll have to concur that ITER is going to be the experiment that retrieves more energy than it puts into it. After that, it's going to be refinements and improvements to figure things out. I don't think it'll replace the world's energy production over night, but it'll definitely be the main form of energy in 100 years from now.

2004-May-28, 01:35 PM
Originally posted by ASEI@May 23 2004, 09:50 PM
Fusion works in the sun, but that is about all I can say for it.
The solar fusion "reactor" theoretically consumes H and produces He:

2e- + 4 H-1 --> 1 He-4 + 2 neutrino + 27 MeV

Measurements provide two puzzling observations:

1. The number of neutrinos coming from the reactor are 0.33-0.50 the number expected. Neutrino oscillations are the currently fashionable explanation for this solar neutrino puzzle.

2. The reactant, H, pours out the top of this "reactor" - - - 3 x 10^43 H per year.

With kind regards,


2004-May-28, 06:42 PM
Solar energy for homes is interesting. It could indeed lower electricity consumption. Industrial processes require a LOT of power though (even the ones that go into producing the solar panels). Could these sorts of power requirements be met with batteries and solar cells? I think some sort of nuclear system would be required. Especially if we want to replace gasoline with some sort of artificial fuel somewhere down the road (read terrawatts of power required).

Fusion that used deuterium is very difficult to acheive (higher activation energy). Ususally all the fusion research is with tritium, because it is much easier to react. Tritium is not all that common though, and the least energy expensive way of getting it is from fission or neutron absorption (which sort of defeats the purpose if you want to eliminate dealing with radioactive substances). I think that even if a fusion plant reached breakeven, it still has a lot of hurdles to go through. It would have to produce enough energy to seperate out the tritium fuel from normal dueterium. It would also have to be cost effective. When your reactor requires either huge superconducting magnets, or extremely large banks of lasers to hit a pellet, not to mention much more cumbersome methods of energy exchange than a simple steam power transfer, things can get extremely expensive extremely fast.

Fission is simple by comparison. You chuck some metal in a pool of water sitting inside a concrete sheild. Even the problem of managing nuclear waste (which is overblown with ludite hysterics in my opinion) is simple. Short of outlawing fission power, I don't see how fusion would compete.

2004-May-28, 09:36 PM
Asei mentioned-
Solar energy for homes is interesting. It could indeed lower electricity consumption. Industrial processes require a LOT of power though (even the ones that go into producing the solar panels). Could these sorts of power requirements be met with batteries and solar cells?

Most of the cost effective applications of Solar energy for homes involves-first, reducing consumption of electricity through better design, conservation and efficiency. The simple application of a radiant-barrier in a vented space in a roof can intercept and remove 80% of the heat which would normally pass into the house, that would then have to be removed by the air-conditioner. The air-conditioning portion of the electric bill is usually about 50% of the total. Several companies make simple heat-exchangers which remove the heat from the A.C. compressor lines, which improves the efficiency of the compressor to remove heat from the building. The waste heat is exchanged into water, enough to supply the entire house with hot water for the day.

These 2 steps can save the homeowners about 60%-65% of 75% of the total electric bill.
50% A.C.
25% Hot water

I could go on, but essentially there are about 450,000+ homes in the United States right now that are off-the-grid, and they are not the homes owned by millionaires. It is very easy to save 80% to 90% of the total electric bill and still maintain a very high quality of life with all the amenities.
Right now, I am keeping my building at 72 on days when the outside temperature in the shade is 95, and I do not have a utility bill!

Photovoltaics are about 10% to a maximum of 15% efficient with regards to converting the available light to electricity. The rest of the energy is available in the form of heat. You never, never, never want to make electricity from PV's and then use that electricity to heat something, like Hot water. It is simpler to use the original 85% to 90% heat content of the available solar, that is why folks:
1) Reuse heat available from other waste sources, like the AC compressor and ,
2) Make up the balance of heat from a solar hot water heater, which is about 80% effficient. Therefore, one can recover about 80% of the remainder of 85% of the solar which is not converted into Electricity.

Most industrial processes consume heat. Solar energy is perfect for heat processes.

Most industrial processes waste a lot of heat. One of the biggest consumers of heat is a kiln, which is used for ceramics and glass and making concrete. Kilns (and industrial process ovens) must reach temperatures of 2000 F to 3000 F. A typical ceramic kiln might take 8 hours to reach firing temperature. The ceramic kilns which I have made use a refractory based insulating material, which Conserves a lot of heat. When I fire it, I can reach the firing temperature of 2400 F in 35 minutes using 1/10 the conventional amount of energy (usually propane).

When the firing is finished, I can dump the heat within the kiln into an adjoining kiln chamber and bring that temperature up to bisque temperature (low-fired, pre-glaze), about 1800 F, essentially reusing the heat again. This could be done several times a day with enough firing chambers staged one on top of each other.

An efficient single-stage kiln can use 1/10th the energy of a conventional kiln.
An efficient 2-stage recycling kiln can use 1/16 the energy of a conventional pair of kilns.
The upper limit for a multi-stage kiln (up to 8 chambers) could be 30 times higher, and that energy could also be supplied from concentrated sunlight. The Phillips corporation, among others, has already done it.

Photovoltaic materials are like computer chips, they are semi-conductors. In firing the material, especially in an innefficient oven or kiln, "much energy" is used. However, the energy cost is calculated into the final cost of the component. If overall, the energy content and cost was so high, how can chips be made more affordable all the time?

Because the concept of "Lots of energy" to make Photovoltaic material is a myth, a fabrication, used in an attempt to detract the public from considering Solar as an alternative.

As another example, I was explaining to a builder once, the difference in pricing for making a home out of concrete versus wood. He commented with the typical "PV type" of cliche' that tremendous amounts of energy went into making concrete. I responded by reminding him that all costs of producing a material is reflected in the final purchase price of the material, and he agreed. Then I mentioned that concrete was still very cheap. He didn't realize that he had been perpetuating a myth.

You can build an efficient house or office and include the Photovoltaic system for the same price or less than a conventional building. The energy that the building saves over decades is so much more than the paltry amount used to make a small number of panels for an efficient building.

By doing a simple end-use analysis of most industrial processes, implementing available solutions and using the engineer part of your brains a little bit, we could dismiss with most of the energy needs in this country.

And one more point, At the current rate of consumption, most sources of nuclear fuel for the existing fission reactors will be used up in 20 to 30 years.

So, it's time to quit asking where you're going to plug in all the old inefficient buildings and factories and systems and tools your grandfather built, and start being creative, and fast. :o

2004-Jun-03, 05:20 PM
Well, increasing the efficiency of some things is possible, but the amount of energy to do some things like, say, heat a home pales in comparison to the amount of energy required to run the nations cars, or it's factories.

As far as I can tell, making semiconducting chips IS a very energy expensive process. Purifying and processing all that silicon and gold is pretty expensive.

There are other tradeoffs that must also be considered. Often, as you approach the ideal efficiency for a process, the device required becomes hyperbolically more complicated and expensive to operate (or the process happens slower). Often, it is a lot more economically feasable to produce more energy than to operate more efficiently. Often, the process with the best economic efficiency is one with horrible energy efficiency. To operate an 8 chamber multi-stage kiln is probably 8 times as expensive. In order to improve economically, the energy available must increase, not necesarily the efficiency.

Finally, there is an ideal efficiency for any process, and it is not 100% (usually it isn't even 50%). And a lot of devices are already pretty close to that efficiency. Attempting to make them more efficient just makes them more expensive, and really only results in marginal energy savings. Take cars for example. People keep talking about the mythical 100 mile/gallon car (and I suppose it it can't carry anything and is made out of plastic, you might get it there), but conventional internal comustion engines cannot thermodynamically get much more than 60% efficiency from the engine. Furthermore, you can only get so much energy out of gasoline. Car engines already approach the ideal efficiency for spark ignition engines. Diesel electric hybrids can go a bit further, but you will never end up with something that hauls 4000 lbs of cargo and gets 100 miles a gallon up a hill no matter what you do with the engine.

This is my problem with "efficiency". In the end, it is only a temporary and partial solution. More energy must be produced to power industry and automobiles, and to do so in a manner where these things are still economically feasable.

2004-Jun-03, 06:40 PM
Asei- Today I am having the fun task of documenting the temperatures in a solar-powered building which is staying at 73F in the full sun with dark shingles and cost 40% less to build than a conventional house. Including the photovoltaic system.

I seems that you did not fully comprehend what I had written in my previous post. I will have more time later to give your response a full reply. Please re-read my post.