It’s an endothermic chemical reaction, isn’t it? I guess you could burn some of the natural gas to power the steam reforming process, but natural gas is a fossil fuel. Hydrogen is an alternative way to use fossil fuel, not an alternative to fossil fuel.
I never said gasoline is an energy source. Oil is an energy source, which is used to manufacture gasoline.
gregonie, how about this project - 200MW solar thermal power station. Each 1 km high monolith will provide enough electricity to power around 200,000 homes.
As chronos said, all power sources derive from either fission or fusion. So isn’t oil just another energy store that is used to create another (more convenient) energy store (hydrogen).
There are ‘natural’ energy stores - oil, geothermal, hydro, tidal,… and man-made energy stores derived from natural stores and just presented in a more convenient form.
eg fusion (in sun) --> light (in space) --> sugars (in plant)–> ethanol (in tank) --> electricity (in battery) --> mechanical (in flywheel)
You might try discussing “Energy Conservation” as a real alternative to fossil fuels.
I know that there is a massive amount of energy wasted in the world.
You might get some extra points for ‘creativity’ by using a topic like this.
And natural gas is an energy source, which is used to manufacture hydrogen. Same diff.
So what exactly is wrong with my original statement, if you agree that neither gasoline nor hydrogen are naturally occuring sources of energy? 
Could someone briefly explain what a wave generator is?
And also, perhaps this is a bit too far-reaching, but why is harnessing the power of the sun so difficult? Isn’t there any way of mechanically harnessing light in the manner that chlorophyll does?
OK, briefly: Attach a float to the crank of a mechanical generator. Let the float bob up and down on sea waves, so turning the crank. Enjoy the free energy. There are many other means to the same end. Stick a pipe in the water and let the waves pump air back and forth. Use the compressed air however you see fit.
If we’re discussing alternatives to fossil fuels, hydrogen produced by steam reforming isn’t one: All you’re doing is devising a means of turning the energy stored in natural gas into energy stored in hydrogen, and spending energy to do it. Much the same, of course, is true of refining crude oil into petrol (Brit for gasoline), but, OTOH, crude oil is difficult to use as a fuel, whereas natural gas is at least as easy to use as hydrogen.
The question is, of course, whether by using a hydrogen fuel cell you can actually end up with a more efficient energy cycle: natural gas → hydrogen → hydrogen fuel cell → work as opposed to natural gas → combustion engine → work. I don’t have the figures to answer that. You need to bear in mind that hydrogen is a bugger of a fuel to transport and use, too.
If solar panels aren’t efficient enough to repay the energy costs of their manufacture, there are other alternatives. Domestic heating by roofing your house with heat-exchangers is one approach. For electrical generation, build yourself a nice big mirror to focus sunshine on a boiler and use the resulting steam to drive a power station. If all you want is heat, don’t bother with a boiler, just use the mirror for a solar-powered smelter. You need reliable sunshine, and at that you get, maximum, twelve hours out of twenty-four on average.
Regarding hydrogen fusion, I remember from “The Mote in God’s Eye” that the Mote world had unusually high levels of helium in the atmosphere. I was sure there was a reference in the book to the obvious implication: They must have been using hydrogen fusion for bloody ages. But I don’t think Earth’s in much danger from helium pollution 
While we’re on the sf angle, Larry Niven points out via some of his characters in “Ringworld” that orbital power satellites etc can, theoretically, present an environmental problem of their own. If you beam enough power down to your planet, you’re effectively increasing its energy input significantly over that which it would normally get from the Sun - and you have to bear in mind that all energy eventually ends up as waste heat. Get rid of all fossil fuel and use only nice, clean solar power, and you could, if you were greedy enough, still end up with global warming…
Almost certainly; at the moment nearly every method of collecting solar power is too expensive, but that need not be the case forever.
15,000 times as much energy fall as sunlight on the Earth each day as is used in our world economy; even if solar energy collection remains inefficient, we could collect enough energy to run a world society at several times our current consumption level.
Unfortunately we would need solar power collectors several hundred thousand square kilometers in extent.
Not impossible- but difficult. There would be economies of scale- call it the next Manhattan project. Better stil, use the oceans as solar power collectors- vast OTEC arrays would extract the warmth from the seas, leaving the land free of obstruction (although energy extraction on too large a scale might affect the currents and global climate- a kind of ‘global cooling’)
In the mean time fission is a real better-than-break-even power source; but fissionable elements will eventually run out.
If fusion becomes available, as it should, there is billions of years worth of energy in the He3 and deuterium throughout the solar system…
and the Sun could be harvested by solar power collectors in close orbit, as it could provide energy for trillions of consumers eventually.
the ultimate alternative energy source - Dark Energy (but that one is a joke, by the way.)
oh yes- wave generators
OTEC
Incidentally, energy conservation is extremely sensible, and certainly should get a mention; this means more energy is available without using any of the alternative sources.
SF worldbuilding at
http://www.orionsarm.com/main.html
Here is the original statement I disagree with:
Hydrogen derived from natural gas through steam reforming produces much more energy than the energy required to sustain the process, so this statement is false. Like refining gasoline from crude oil, there is a net gain in energy after the steam reforming process. In this way, hydrogen is a source of energy.
The difficulty with wave generators is simple physics and engineering. The energy of a wave is proportional to the fourth power of its amplitude…a generator would need to be sensitive enough to create decent power out of a 2 metre swell, yet would have to withstand a battering of some 4000 times as much energy, from waves 8 times the height. A hell of a task for the engineers.
It does not, however, produce any more energy that that required to sustain the process plus the fuel value of the natural gas - which can already be used to fuel power stations, provide domestic heating and cooking, and drive automobiles. This is why hydrogen is still not a net source of energy unless using hydrogen in fuel cells is much more efficient than burning natural gas directly.
One advantage of using hydrogen as fuel is that it is clean at the point of use - but steam reforming still produces CO[sub]2[/sub] as a waste product; the only advantage there would be that at least the CO[sub]2[/sub] can be kept in one place.
But that is not what I was arguing vís a vís scr4’s statement. All I am saying is that the commercial production of hydrogen is more efficient than scr4 suggested when he stated that hydrogen is produced by the electrolysis of water.
Agreed. I don’t know how efficient cracking water is, but I’m prepared to bet it’s fairly horrendous. Steam reforming may be less wasteful. OTOH you could drive electrolysis with free, clean solar power if you can’t come up with a better way to use solar power. I imagine there’s a market for the oxygen, too.
Over here in the UK, we’re using natural gas to fire power stations, which is silly when you think about it - a fuel that is clean and convenient to use directly in the home or in LPG road vehicles wasting plenty of its potential just to be converted to electricity. :rolleyes:
Lots of questions to be raised:
Energy source vs. Energy medium doesn’t seem to me to be the black-and-white issue others have suggested here. Significant amounts of petroleum products are being used to move “automotive vehicles” (everything from a moped to a diesel locomotive, including ships and aircraft). Can an alternative means of supplying them with power and/or fuel be devised? Certainly, and there are numerous options. In many cases, you’re talking an energy medium that itself consumes energy in being created – but it will alleviate some significant problems to have an immobile plant producing such power/fuels which are then consumed by the mobile vehicles.
While geothermal/wind/hamsters-turning-wheels or whatever may have real advantages, what proportion of the overall energy budget can be supplied by them? And, even if this is small, is it worthwhile engaging in it in terms of overall trade-offs on the basis of “every little bit helps”?
Past problems with energy modes do not preclude proper intelligent use of them. I can give you horror stories about acid rain and particulate pollution from coal plants – but Una Persson, who is an expert in the field, can provide you with economically feasible means of running clean coal plants. Three Mile Island and Chernobyl illustrate reasons for not allowing nuclear plants to run unsafely – but they can be designed to be safe.
The recent foofaraw about wind energy along the Massachusetts coast points out one of the big trade-off questions on one alternative source. Careful examination of what would be the implications of any given alternative source, with critical, skeptical, worst-case examination of the impacts of that source, is needed.
Fusion has its own problems (controlling tritium, for example) – but a big part of why it’s considered pie-in-the-sky is that nobody has been willing to devote the resources to effective research into how to use fusion economically and safely that have gone into almost anything else. Jimmy Carter set the country on a “fusion is not feasible” course and everybody since has rubber-stamped that. I think it’s worth spending a small fraction of the country’s GDP on a good R&D program to see if fusion can be a feasible energy source.
Biomass is reusable – but there is a cost/benefit question there. If municipal waste, it takes a lot of sorting and drying costs to prepare it. If you’re burning wood, are you prepared to recycle the amount of forest it would require to support a bunch of such plants? (That includes having them cut and ensuring they’re replanted and growing at the proper rate to be reusable a decade or three down the road.)
There are lots more questions than answers here, and it requires some intelligent digging through all the questions to come up with good programs that solve rather than creating problems.
Hydrogen (H and/or H2) is available in nature, just not on Earth.
Also, there has been some work on bacteria that make Hydrogen. Certainly not commercialy viable, but worth more research.
gesychronous orbiting solar arrays could work better than moon based ones (remember the inverse square law)
Brian
But you can burn it at higher temperatures producing higher efficiencies than you could achieve in a car or a house.