23 Aug 11
Originally posted by sonhouseIt is however easier to generate electricity from multiple sources than hydrogen.
That said, you have to get the electricity to store in batteries somewhere, the two are separate issues.
It is also easier to transport electricity.
Hydrogen has one advantage, it is probably easier to store, so it might have a significant efficiency advantage there - but only if the storage potential of car batteries is not used efficiently. If people charge their batteries during off peak times, they may even use current electricity supplies more efficiently and thus essentially score over 100% efficiency.
You can generate H2 from solar energy using catalysts and such and I see signs of higher efficiency there every week.
And how does that compare to traditional photovoltaics?
The biggest problem I see with hydrogen, is countries like Zambia that have abundant hydroelectric power sources, would be left out of the equation.
23 Aug 11
Originally posted by twhiteheadI think H2 production from solar catalysts are comparable to the best PV cells, so far anyway. You never know when the next breakthrough will be announced, stuff is announced almost daily, better batteries, H2 production, desalinization more efficient, better PV's.
It is however easier to generate electricity from multiple sources than hydrogen.
It is also easier to transport electricity.
Hydrogen has one advantage, it is probably easier to store, so it might have a significant efficiency advantage there - but only if the storage potential of car batteries is not used efficiently. If people charge their batterie ...[text shortened]... s like Zambia that have abundant hydroelectric power sources, would be left out of the equation.
I think that question will be answered in a couple of years, which is best efficiency wise.
Hydroelectric power has its own downside though, because the rivers are dammed for miles and that alters the ecology of the original river, species are lost, new ones gained, not always for the better.
There is serious talk here in the US about abandoning some hydro plants. Of course places like Hoover Dam is too dam big to destroy, it would probably take a small nuke🙂
There was a dam that broke in West Virginia a few years ago that buried a town in mud and broken trees. That kind of thing can ruin your whole day.
24 Aug 11
Originally posted by sonhouseI realize that, but in some cases (eg Zambia), it remains one of the best sources of power.
Hydroelectric power has its own downside though, because the rivers are dammed for miles and that alters the ecology of the original river, species are lost, new ones gained, not always for the better.
We should also be using more solar power, and possibly wind, though Zambia generally does not have a lot of potential there. The best places for wind power tend to be coastal.
But it makes far more sense to produce electricity at all these sources and transport it to cars, than to try to make hydrogen, transport it to cars then convert it back to electricity.
I am yet to see any good argument for a 'hydrogen economy' and until I do, will remain convinced that it is a ploy by auto-makers, oil companies etc to shift the focus away from electric cars (which will greatly hurt both industries).
25 Aug 11
Originally posted by twhiteheadI think the outcome of electric V H2 is not over by a long shot. The battery problem with electrics has to be resolved first and the driving range of both technologies has to be improved. If you have an all electric vehicle that can only go 50 kilometers before recharge, you can't expect that vehicle to be used for commuters who regularly drive like me, over 160 km round trip. At least with gasoline or petrol if you prefer, I could do that and refill only every other day or so, newer cars with better mileage and 500 mile or 800 km range could do that trip all week without refueling.
I realize that, but in some cases (eg Zambia), it remains one of the best sources of power.
We should also be using more solar power, and possibly wind, though Zambia generally does not have a lot of potential there. The best places for wind power tend to be coastal.
But it makes far more sense to produce electricity at all these sources and transport ...[text shortened]... nies etc to shift the focus away from electric cars (which will greatly hurt both industries).
I realize that kind of commuter driving is mostly confined to large countries like the US but it is a factor and will remain a factor.
BTW, there was a study done on wind power and they found there is a limit to how much wind power we can extract without hurting the world ecology and that turns out to be a lot smaller than the total world use of energy so it is more of a local usage thing, a wind farm offshore here and there but it is probably not going to ever give us more than a small fraction of total energy use.
Of course every bit helps, 1 gw of wind means one less nuke plant.
Solar has its own problems with distribution aside from the cost of panels and such.
In the US for instance, the most efficient use of PV would be in the southwest desert area for obvious reasons. The problem with that is there is not much in the way of major high voltage distribution lines in that part of the US so the estimate is something like a half trillion US dollars to build one which pretty much sucks, even if we come up with 50% efficient PV cells that only costs ten cents a watt to make.
Which of course is only a dream but you get the idea.
H2 is only a battery, not a source of energy and as such requires an infrastructure but as it turns out, we already have an infrastructure in place for petrol, gas stations.
Since we already have that system in place, it would not be that big a deal to upgrade the pumps to H2. Not that easy, but not like having to start from scratch.
I already showed the problems with electrics where batteries CAN be charged in 4 or 5 minutes but is unlikely to ever reach the consumer due to the problems I already raised. So we will be stuck with some kind of drive in replacement system or slow charge stations because of the power requirements of charging a battery in 5 minutes, near a megawatt per each battery, not a good idea to have that much energy near the public. That would be asking for trouble at this stage of the game technologically speaking.
So there are pluses and minuses with all of these infant technologies, may the best solution win.
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25 Aug 11
Also I would point out that if domestic users draw megawatt levels of power for
a few minutes every time they park their car in their garage (assuming they have
one)
Then electricity demand is going to get impossible to balance. and peak is going to
exceed capacity.
Also if you are transmitting power to all the people using it to charge their cars
you have to factor in losses to the grid in your efficiency calculations.
25 Aug 11
Originally posted by googlefudgeManaging the grid will be a big problem in any system, but I thought that such fast charging may actually help. Like this, some slow charging battery at home could charge slowly during the day and then that battery would charge the car, minimizing the toll on the grid.
Also I would point out that if domestic users draw megawatt levels of power for
a few minutes every time they park their car in their garage (assuming they have
one)
Then electricity demand is going to get impossible to balance. and peak is going to
exceed capacity.
Also if you are transmitting power to all the people using it to charge their cars
you have to factor in losses to the grid in your efficiency calculations.
There's obviously more loss, but how much more inefficient do you think that would be?
25 Aug 11
Originally posted by googlefudgeWell the main point is, at least for now, there is no way to get megawatt levels of energy into a car battery, at least in the car, safely. Like I said, say you really need megawatt levels, 1000 volts DC at 1000 Amps. Not gonna happen.
Also I would point out that if domestic users draw megawatt levels of power for
a few minutes every time they park their car in their garage (assuming they have
one)
Then electricity demand is going to get impossible to balance. and peak is going to
exceed capacity.
Also if you are transmitting power to all the people using it to charge their cars
you have to factor in losses to the grid in your efficiency calculations.
26 Aug 11
1 edit
Originally posted by sonhouseI do realize that for all cars to be electric, we need greater range.
I realize that kind of commuter driving is mostly confined to large countries like the US but it is a factor and will remain a factor.
However, many people would live with the shorter range (I would), and many people who have two cars, could live with one being electric. In Europe, where people are more socially responsible than the US, I think short range electrics would catch on really fast if they were being produced at a reasonable price.
BTW, there was a study done on wind power and they found there is a limit to how much wind power we can extract without hurting the world ecology and that turns out to be a lot smaller than the total world use of energy so it is more of a local usage thing, a wind farm offshore here and there but it is probably not going to ever give us more than a small fraction of total energy use.
I don't think its as small a fraction as you suggest, but I need to do a bit of research to prove it and Wikipedia isn't working for me right now.
H2 is only a battery, not a source of energy and as such requires an infrastructure but as it turns out, we already have an infrastructure in place for petrol, gas stations.
Since we already have that system in place, it would not be that big a deal to upgrade the pumps to H2. Not that easy, but not like having to start from scratch.
Actually, from what I have read, the idea was to pipe hydrogen around, not transport it in trucks. So yes, totally new infrastructure would be required.
26 Aug 11
Originally posted by googlefudgeBut if the current system, of charging your car over night during off peak is used, then we essentially get free power (as most power produced during off peak just goes to waste if it is not utilized).
Also I would point out that if domestic users draw megawatt levels of power for
a few minutes every time they park their car in their garage (assuming they have
one)
Then electricity demand is going to get impossible to balance. and peak is going to
exceed capacity.
26 Aug 11
Originally posted by sonhouseWikipedia is back up.
BTW, there was a study done on wind power and they found there is a limit to how much wind power we can extract without hurting the world ecology and that turns out to be a lot smaller than the total world use of energy so it is more of a local usage thing, a wind farm offshore here and there but it is probably not going to ever give us more than a small fraction of total energy use.
http://en.wikipedia.org/wiki/Wind_power
Apparently wind power already supplies "about 2.5% of worldwide electricity usage."
So if we increase wind farms 50 fold, we can get 100% of the worlds electrical power from the wind. I honestly don think that is impossible, nor is it going to hurt the ecology of the world significantly.
I realise that this does not include other energy use such as natural gas, coal and other fossil fuels not being converted to electricity, but surely even that is within sight based on the above figures?
Also read this section:
http://en.wikipedia.org/wiki/Wind_power#Wind_energy
26 Aug 11
3 edits
Originally posted by twhiteheadI think the world wide consumption of electricity is about 14 terawatts, 14,000 gw.
Wikipedia is back up.
http://en.wikipedia.org/wiki/Wind_power
Apparently wind power already supplies "about 2.5% of worldwide electricity usage."
So if we increase wind farms 50 fold, we can get 100% of the worlds electrical power from the wind. I honestly don think that is impossible, nor is it going to hurt the ecology of the world significantly.
...[text shortened]... above figures?
Also read this section:
http://en.wikipedia.org/wiki/Wind_power#Wind_energy
If wind does 2.5 percent, total would be 350 odd gigawatts. I didn't know there was that much coming off wind.
But if we did multiply it by 50, there may be ecological consequences we don't see now.
At any rate, nobody would suggest hanging our hat on one energy technique.
For one thing there is too much politics going on to quickly kill coal for instance, and then there is the Nuke lobby, all these forces will ensure the lasting signature of these supplies. That is world wide, not just in the US. For instance, China is now the worlds largest user of coal for energy production, already passed the US and now is the largest contributor to greenhouse gasses, although they are trying to get rid of coal as fast as they can but economic giant or not, you can't do it overnight.
I found this wiki piece, it has somewhat different figures:
In 2008, total worldwide energy consumption was 474 exajoules (474×1018 J=132,000 TWh). This is equivalent to an average energy consumption rate of 15 terawatts (1.504×1013 W)[1] The potential for renewable energy is: solar energy 1600 EJ (444,000 TWh), wind power 600 EJ (167,000 TWh), geothermal energy 500 EJ (139,000 TWh), biomass 250 EJ (70,000 TWh), hydropower 50 EJ (14,000 TWh) and ocean energy 1 EJ (280 TWh).[8]
Still, if we want to depend on electricity as our main source of energy, there will have to be massive upgrades to the high voltage distribution lines because the renewable resources are seldom in the area where the lines are so new ones have to be built and that would probably total in the trillions for the world, estimates put it at half a tril in the US alone for distribution upgrades.
Your point about H2 being delivered by pipeline I don't think will fly because of the existing infrastructure of petrol, too much invested in a proven energy distribution system.
It isn't that much of a technological jump to go from petrol at room temperature to liquid hydrogen, since we already have major companies doing just that.
I work in the semiconductor cleanroom industry and have worked directly on LN2 and O2 liquids and the trucks that carry those products carry liquid hydrogen.
For instance, NASA uses millions of gallons of H2 already in launch vehicles since H2 combined with O2 is just about the best chemical rocket fuel available cheaply on the periodic table.
Liquid H2 is a very small part of the expense of launch, NASA has developed the delivery technology for decades now, it can relatively easily be expanded to cover the whole US for starters.
Not that I am saying that is the best way to go, I am just saying if the lobby dudes and the money dudes get together, they may do just that.
Even given all that infrastructure of trucks, H2 still has to be generated and as efficiently as possible.
If H2 is used as a fuel it would be infinitely more desirable than petrol and can run in the same engines with little modification. That is the up side of the deal.
One big problem with all these energy consumption numbers is that is how it is now. If you look at those figures I supplied, Solar, for instance, can provide about 4 times the total energy consumption of TODAY.
If we continue on the same energy consumption curve, in a hundred years we may need to use more energy than we can get from ANY renewable. What if the energy consumption goes up to 100 Tw average? 200 Tw? What resources would we have for that kind of energy use?
It looks to me like fusion energy better come on line pretty dam soon. It's a source always 20 or 30 years in the future and that future better happen soon or we will not have enough energy for our lives when we have 10 billion population, 15 billion and so forth.
Unless there is a major catastrophe such population numbers are inevitable.
I think we are headed for a major correction myself, within the next 100 years. Of course not many of us will be alive then that are alive now, my grandkids maybe but if we don't kick the fossil fuel habit soon there will be dire consequences.
26 Aug 11
Originally posted by sonhouseActually that is a bad thing - but what the car companies desire. Internal combustion engines are expensive and the spare parts market is massive. Electric cars have much lower maintenance issues. Also, removing the weight of the engine can be a massive energy boost. So if we must go with hydrogen, then fuel cells are far more desirable than internal combustion. (also fuel cells are, I believe, significantly more efficient).
If H2 is used as a fuel it would be infinitely more desirable than petrol and can run in the same engines with little modification. That is the up side of the deal.
It looks to me like fusion energy better come on line pretty dam soon. It's a source always 20 or 30 years in the future and that future better happen soon or we will not have enough energy for our lives when we have 10 billion population, 15 billion and so forth.
Although I agree, it is less about population, and more about wealth (as China is demonstrating).
In fact, I believe many developed countries are reducing their energy consumption with time.
But I think you underestimate the potential of renewables.
26 Aug 11
1 edit
Originally posted by twhiteheadI sure hope I misunderestimate renewables! Still a multi-trillion dollar proposition.
Actually that is a bad thing - but what the car companies desire. Internal combustion engines are expensive and the spare parts market is massive. Electric cars have much lower maintenance issues. Also, removing the weight of the engine can be a massive energy boost. So if we must go with hydrogen, then fuel cells are far more desirable than internal comb eir energy consumption with time.
But I think you underestimate the potential of renewables.
I was pointing out the possibility of H2, didn't say it was wise.
H2 into fuel cells would be efficient for sure, at least with a bit more development.
It would force the conversion to electric and I see development of in wheel electric motors, which would have some downsides but would give the car a lot more room for goodies.
Another development I am breathlessly waiting for: Room temperature superconductors.
Man, that would shake the game for sure! If you had very flexible RT SC's, the whole power train from wiring to the motors themselves could be made from them, motors 1/10th the weight and such and 99% efficient. Then you would have something! Combine that with solar paint to charge batteries in the daylight hours while you are at work or to make H2 inside the car and things begin to look serious!