Solve the World's Energy Needs? Any Non-Fusion Possibilities?

[skywolf]

Nuclear power plants on mars...
then send the energy back through microwaves

 

[brewnog]

I have designed a pressure cylinder into which I inject water as a mist with a fuel injection system and the best part is I have a microwave amplifier in the cylinder to heat the mist quickly. Voila, almost instant steam and the batteries can be recharged while you drive. I can't wait until I am fully operational I will take great delight stopping at service stations to wash the windows and top up with water.

I hope you're joking. What powers your microwave?

 

[eeka chu]

Seriously, the only way to solve the energy problem is to stop wanting so much energy.

That's a good point but I was thinking about it for a while. Once we have fusion and superconduction, power ratings for devices will probably increase. E.g. computers at the moment use hundreds of watts. A calculation in the processor require energy to flow, therefore you have a watts per calculation cost. Processors are quite likely to start copying supercomputer layouts soon, the dual core already has, whereby you'll have lots of individual processors in one computer. So we'll end up using kilowatts for computers and that could even go on to megawatts I suppose.

I don't think that's such a problem. The key is, not to be wasteful. Just because we have a lot of free energy to hand, let's spend and extra five minute designing a better chip that saves some juice per calculation.

Lets not leave our lights on just because we can't be bothered switching them off.

Of coarse, it's cheap enough for us to ignore these bits of advice at the moment. And the act of leaving the light on is quite disconnected from the juice bill, and certainly far disconnected from the effect it creates at the powerplant, which then flows out of the plant's exhaust and into the atmosphere. As for the icecaps, forget it.

We can indulge in our supercheap juice when fusion and superconductors come along, but we should start punishing, very severly, those who outright don't care about the efficiency of their products. Car manufacturers for instance. It shouldn't be an option for them to produce an engine that wastes more than 50% of it's fuel as heat in the same way that it's not tolerated if the car spontaneously burst into flames.

They can say that kind of thinking will push their prices much higher and mean less people have cars, which will harm society, but we've already witnessed that the alternative also runs a high, nameless, price tag.

I know people who will drive literally a few hundred meters, perhaps even less, and when the weather if fine to walk it. Incredible!

Perhaps as space based platforms become cheaper we might be able to deploy some form of solar collector farm in space, where the wattage will be much higher, and then direct the energy back through the atmosphere in a form that will undergo reduced absorption?

But I think fusion is probably the way it's going to go. We can't be far off now. And superconduction is still edging it's way forward with updates of the theory and some new conductors with impressive temperature requirements.

 

[vanesch]

So we'll end up using kilowatts for computers and that could even go on to megawatts I suppose.

And not to forget the airco that will evacuate the heat in the room

I don't think that's such a problem. The key is, not to be wasteful. Just because we have a lot of free energy to hand, let's spend and extra five minute designing a better chip that saves some juice per calculation.

I think you underestimate the efforts of the engineers designing all that pretty stuff: cutting down on power is a MAJOR issue. Not so much for ecological reasons, but because waste heat is a major engineering pain.

Car manufacturers for instance. It shouldn't be an option for them to produce an engine that wastes more than 50% of it's fuel as heat in the same way that it's not tolerated if the car spontaneously burst into flames.

The 50% is dictated by thermodynamics. A combustion engine will never be 100% (or even 80%) efficient. Internal combustion engines are already pretty efficient when it comes down to comparing them to what they potentially COULD do, within the limits of thermodynamics.

Perhaps as space based platforms become cheaper we might be able to deploy some form of solar collector farm in space, where the wattage will be much higher, and then direct the energy back through the atmosphere in a form that will undergo reduced absorption?

The problem is: getting the stuff up there. Costs a lot of energy and exhaust gasses.

But I think fusion is probably the way it's going to go. We can't be far off now. And superconduction is still edging it's way forward with updates of the theory and some new conductors with impressive temperature requirements.

I wonder what's this obsession with superconductors. In fact, I've SEEN several popular "scientific" documentaries (aimed at promoting the benefits of research on superconductors) telling the FALSE FACT that superconductors would give us "energy for free" or things like that, but that is BLUNTLY NOT TRUE. Electricity generation, transformation and transport IS ALREADY 90+% efficient. Big transformers and generators easily score in the 98% range. Transport is a matter of economy: you can make the transport as efficient as you want (section of the cables, voltage used - hence insulators used). You can go for 99.99% if you want to. But from a certain point onward, the investment becomes ridiculously high as compared to the efficiency gain. And if the transformer is 98% efficient, then there's not much use in having the line being 99.9% efficient: you can cut the cost roughly by 10 by making it only 99% efficient.

So if we replace all that conventional stuff by expensive superconductors (which shouldn't be cooled, because if they need to, you need to account for the energy in the cryogenics, which makes them also less than 100% efficient), you'll go from an overall, say, 95% to 99.8% or something.
Not 100% in any case, because there WILL still be losses, be it from radiation, friction in the generators, etc...
So all that pain for less than 4% gain.

However, there's one TRUE potential application for superconductors in electricity distribution, which is instantaneous power storage and relief. The MAJOR difficulty for a utility is to adapt its production to consumption. There's no way of storing electricity in huge amounts, so production needs to follow consumption. And consumption is highly erratic, which means that utilities need to have at their disposition "rapid-reaction" generators, like gas turbines. Big power plants, such as fission (and certainly fusion!) reactors do not have time constants of a few seconds.
So if one could construct devices which could store huge amounts of electrical energy, that would be great: during the day, they could charge up, and in the evening, for instance, they could provide for the extra demand, hence smoothing out the demand on raw production, so that expensive and wasteful means (such as gas turbines) can be disposed off.
Now, one such technique would be huge coils in which one sets currents of billions of amps circulating, and THAT would be nice with superconductors. Kinds of "magnetic flywheels". But the problem is that superconductors don't like magnetic fields, and don't support high current densities.

 

[eeka chu]

I think you underestimate the efforts of the engineers designing all that pretty stuff: cutting down on power is a MAJOR issue. Not so much for ecological reasons, but because waste heat is a major engineering pain.

I appreciate the efforts some designers take, but efficiency usually takes a backseat unless the application is battery powered. Designers have really only started implementing efficiency because they've been forced to by a.) regulations b.) their market refusing to keep replacing batteries (both literally and metaphorically). Less often, they can make use of a somewhat unrelated discovery to improve the efficiency of their own system with little cost to themselves. The very last option is improving efficiency out of heart, because it's simply money wasted in the eyes of most companies. If you can strap a Chinese $2 fan on it and have it work, it's getting the fan baby!

The 50% is dictated by thermodynamics. A combustion engine will never be 100% (or even 80%) efficient. Internal combustion engines are already pretty efficient when it comes down to comparing them to what they potentially COULD do, within the limits of thermodynamics.

I'm guessing you mean the way in which the power is generated means that a large amount of surplus heat is also generated. It's only efficient when you decide that the waste isn't important in your calculations for a publicised efficiency figure (A view I'm 100% positive all car manufacturers will take). That heat is wasted because it could be recollected. The system would no longer be just a normal piston combustion engine, but it could be retrieved. Here we have a working example of the fan philosophy. The system to recover that thermal energy might cost a few thousand more capital on the car's price, and the system could even recover those costs over the miles of petrol wasted in generating heat, but the manufacturers just go with a fan infront of a radiator. If everyone else is doing it you're on kind of even footing with regards to recovering distance via wasted petrol and the first person to change has to put all the work in; it's in their group interest in a way to not bother trying to do this, although that may soon start to change as oil runs out (hell, it might even run out before they get a chance to launch such a product). Bring out your higher capital model and only the squares who think five / ten years ahead will buy it.

The problem is: getting the stuff up there. Costs a lot of energy and exhaust gasses.

+1

What we could really do with is a planet full of resources and virtually no gravity.

I wonder what's this obsession with superconductors. In fact, I've SEEN
[snip]
So all that pain for less than 4% gain.

Well, 4% of a national grid is a huge chunk of juice (and even it costs a few million to produce a cheap room temperature superconductor, you'll still $$$'s in), but I'd be more interested in the smaller scale roles. Computing for instance. The number one problem with conventional digital computing is heat generation. As we get those multicore processors I was talking about that use kilowatts / megawatts, it'd be nice to anhilate all the heat generated by using superconductors for the logic circuits. It'll also help with getting higher speeds out of the circuits as we approach the single atom ?boundary?.

We are lucky to have copper. Reasonably cheap, but still an excellent conductor.

However, there's one TRUE potential application for superconductors in electricity distribution, which is instantaneous power storage and relief.
[snip]
superconductors don't like magnetic fields, and don't support high current densities.

And that's an even bigger problem if you're talking about renewable energy, which also occurs in transients. There you have both sides acting eratically and so an even small chance that the two will occur in unison.

Superconductors are already being used for energy storage but not in the way you mentioned. Rather, they're used for the bearings on ultra-high energy flywheels and gyroscopes. In space, where it's already quite cold, superconductor bearings are used on gyroscopes (Only a few inches big thanks to the speeds they can now rotate) to keep satellites pointing the right direction. A lighter, high speed mass compared to a heavy, low speed mass has a higher energy storage value. The size and weight advantages are, obviously, a big thing for space based equipment.

Since superconductors totally reject magnetic fields impinging on their surface, the bearing is pretty much 100% efficient. Although, a normal magnetic bearing can't be much less efficient, so they must be fighting for a few percent at most I would have thought. Especially since the superconducting bearing probably needs at least some degree of refridgeration should sunlight hit the satellite; micro-cryofridges are the happening thing it seems.

There are natural energy stores as well. Here in the UK, in Wales, there's a big lake high up. When the demand on the national grid falls, the surplus energy is used to pump water into the lake. As the demand rises, water runs back out through a hydroelectric power plant. Of coarse, it's not 100% efficient but it's better than nothing.

 

[Tzemach]

Back again - sorry about the delay in responding but I am in Australia and so about 16 hours out of sync with most of you.
I notice my concept of microwave steam generator caused a bit of comment. The reason this works is that the amount of steam generated is relatively small - it only has to continually recharge the batteries. The steam is not driving the vehicle, there must be someone who likes doing the math, how do we get 30mpg out of a gallon of water - not with a steam engine.

The use less energy has been a barrow that I have pushed for years, there is not a household in the world that truly needs to run on 110volts (or 240V as we do in Europe and Australia). Everything that the ordinary person needs can be delivered by 12v systems and this has been the case since the development of transistors in the 1950's. We are using twenty-first century technology with an 1890's power supply. How smart is that?

 

[Pengwuino]

The use less energy has been a barrow that I have pushed for years, there is not a household in the world that truly needs to run on 110volts (or 240V as we do in Europe and Australia). Everything that the ordinary person needs can be delivered by 12v systems and this has been the case since the development of transistors in the 1950's. We are using twenty-first century technology with an 1890's power supply. How smart is that?

So are you really proposing we switch over to DC power to transmit our electricity?

 

[Tzemach]

No I am definitely not proposing switching transmission to DC but if we design our houses to run on DC we only need about 12V 50A at the board instead of as here in Australia 240V 3000A. I don't even use that much for the welder in the shed.

 

[AlphaNumeric]

12V 50A, that's 600W in total! Not enough for an entire household.

I think my house (or rather, my parents' house) can do 240V @ 40A so almost 10KW. We never get close to that, but easily go past 600W.

Are you sure you get 240V @ 3000A? That's 720KW of power you can draw from the grid! Besides 3KA is an insanely high voltage. I think the UK grid transmits at over 500 KV in order to get a very very low current (since the power loss relates to the current) but then transformers step it down to the 240V homes get.

 

[vanesch]

Everything that the ordinary person needs can be delivered by 12v systems and this has been the case since the development of transistors in the 1950's. We are using twenty-first century technology with an 1890's power supply. How smart is that?

You do realize that running something on 12V or 110V or 220V doesn't change anything to its energy consumption, right ?

The reason we still use 19th century transformer concepts (although greatly improved thanks to finite-element simulations etc) is that it is an *almost perfect* apparatus.
You could just as well complain about the use of a rope and pulley.

 

[vanesch]

I appreciate the efforts some designers take, but efficiency usually takes a backseat unless the application is battery powered. Designers have really only started implementing efficiency because they've been forced to by a.) regulations b.) their market refusing to keep replacing batteries (both literally and metaphorically).

Not really. In digital circuitry, almost everything has been changed into CMOS technology, which is as power-efficient as you can get: in a static state, there's essentially NO consumption, and the only consumption you have is by the charges that are transmitted from the V_cc to ground, first when charging a gate (to close the circuit) and then to discharge it (to open the circuit). The energy loss is equal to the charge transmitted times the power supply voltage. The minimal charge required is determined by the size of the gate of the transistor, which is determined by the smallest features one can integrate on a circuit (currently I think we're around 60 nanometers or so). People try hard to get this smallest feature smaller. Next, people lower the supply voltage: first it was 5V (TTL), then 3.3V, and I think we're down now to 1.5V.
Now, of course, the other aspect is the complexity of the implemented function and the smartness by which it is simplified. It is true that there, one puts a hold on optimizing further "if it fits". But the fundamental cells in a digital CMOS circuit are about as optimal as technology permits.

I'm guessing you mean the way in which the power is generated means that a large amount of surplus heat is also generated. It's only efficient when you decide that the waste isn't important in your calculations for a publicised efficiency figure (A view I'm 100% positive all car manufacturers will take). That heat is wasted because it could be recollected. The system would no longer be just a normal piston combustion engine, but it could be retrieved.

Well, the idea of an internal combustion engine is, eh, combustion (= a heat source from burning fuel). Now, it is a fundamental thermodynamical law (the second law!) that tells you that heat, obtained at temperature T1 can only generate an amount of useful work from the heat, and that the rest of the heat must be wasted to the environment at temperature T2. The ratio of T1 to T2 determines the percentage of the heat that can optimally be converted (look up "Carnot engine" which is the perfect thermal engine). So you will NEVER be able to build a car without a radiator, based upon a heat engine such as an internal combustion engine.
And current cars are not very far from this ideal engine.

The system to recover that thermal energy might cost a few thousand more capital on the car's price, and the system could even recover those costs over the miles of petrol wasted in generating heat, but the manufacturers just go with a fan infront of a radiator.

No amount of money would do away with it, because it is against the second law of thermodynamics. Now, of course, you could do still SOMETHING with the heat (after all, it is about at 80 degrees, while the environment is colder, so you could still extract a little bit of work there), but it would be so tiny that it isn't really worth the effort, to have the radiator at, say, 30 degrees instead of 80 degrees (and hence have a BIGGER radiator).

Computing for instance. The number one problem with conventional digital computing is heat generation. As we get those multicore processors I was talking about that use kilowatts / megawatts, it'd be nice to anhilate all the heat generated by using superconductors for the logic circuits.

Well, for one, there will always be waste heat in computing, but it is true that this theoretical minimum is much smaller than what's wasted now. Nevertheless, the way things are done now are about as optimal as can be done, with current existing technology.

Superconductors are already being used for energy storage but not in the way you mentioned. Rather, they're used for the bearings on ultra-high energy flywheels and gyroscopes.

I'd think these are permanent magnets, no ? Superconductors in bearings ? Never heard of it. Any docs ?

There are natural energy stores as well. Here in the UK, in Wales, there's a big lake high up. When the demand on the national grid falls, the surplus energy is used to pump water into the lake. As the demand rises, water runs back out through a hydroelectric power plant. Of coarse, it's not 100% efficient but it's better than nothing.

Yes, and that's a good technique, if you have a lake at your disposal :-)
Not really the most compact device, but it works well.

 

[Tzemach]

Back again after the usual delays. I mention our extravagance with electricity because I grew up in area where there was no electricity supply. We used the same kerosene lamps, candles and wood fires that our ancestors did for hundreds of years. If anyone has seen the Australian movies "The Man From Snowy River" I lived next door to the cabin in which Kurt Douglas' character resided.
I installed a 12v system there and it provided light, radio, TV and all the mod. cons. We don't need to use the amount of power we usually do, heating and cooling are probably the only real need for heavy power consumption.

 

[keinve]

well, we don't exactly use low polluting energy right now. it really depends on the area. for instance, it's always sunny and windy where i am, and I'm also on a hotspot. thus, solar, wind, and geothermal energy would suit me.

 

[Dissonance in E]

I\ve always wondered about this, why can't piezo crystals be integrated into floors and such to provide elctricity?

 

[IMP]

This was an old thread brought back to life.
I think the first major step is to get the cost of solar panels way down from what they are today. When we can place panels on all roofs everywhere and just use 'the grid' as the means to store and distribute that electricity, we will have made great strides. Of course wind, hydro, geothermal, and nuc will play a part.