True Alternative Energy Sources

Factual Questions
1

It’s College Scholorship Essay time again, and…I need help.

“Discuss the role and limitations of one scientific discipline (biology, chemistry, nursing, or physics) in solving one of the societal problems listed below:”

And I chose “Alternatives to fossil fuels”.

So, what’s the role of physics in finding alternatives to fossil fuels.

Now, I want to find some true alternative energy sources to focus on. The problem I’m having is cutting through all the lobbyist BS. Also, I probably shouldn’t talk about the “chemistry” types of alternative fuels, ie, ethanol and biomass, since they are out of the realm of physics in a way.

These are the energies I could think of, that also directly relate to physics:
–Hydrogen Cells
–Solar
–Wind

Questions:
Which one of these energies have the most feasability (Economically/Logistically) and potential? Are there any others I could consider?

2

Spell it College Scholarship Essay and it’ll blow their socks off…

3

All kidding aside, we don’t do a lot of homework around here.

If I were asked though, as I have been, I’d use physics to show that there are really no alternative energy sources. You can talk about your genreation two and three stars, sure, but they’re going to burn out too.

And forget about fusion. I can just hear our descendants a few thousand millennia down the road whining about how we mined their precious birthright of Big-Bang hydrogen with no regard to the future.

Sheesh…

4

Well aside from it being ‘homework’, I have an honest interest in knowing. It seems to be difficult to do an internet search that discuss alternatives to fossil fuels that doesn’t give you “Wave Of The Future” crap. I would just like to know what the intellectual community truely thinks about renewable energy.

5

I wasn’t trying too hard to be flip.

I was throwing out the idea of impossibility of any truly alternative energy source.

I have no idea of what the recipients of your essay expect. I just thought it might be fun to point out the whole Universe is still running down the entropy hill from the Big Push.

Good luck on yah.

6

My best bet would be plain, old, boring diesel. All car makers are doing a lot of R&D on new engines running on it. Many believe that passenger cars will phase out gasoline and turn to diesel. Forget about all the electric crap (including hydrogen cells). Diesel is the fuel of the future.

7

You will not find a consensus answer on such topics. There is no single “intellectual community.” You need to review both sides of the issue and decide for yourself.

By the way hydrogen isn’t an alternative energy source. Hydrogen is manufactured, not mined, so it’s just a method for energy storage and transport.

And why did you omit nuclear power?

8

Indeed…there is still nuclear power. It supplies 75% of France’s energy needs, without any major accidents that I can think of. And 35% of Japan’s energy, too.

9

:confused: How do you make hydrogen? Take an electron and a proton and join them together? If you take it from water, I contend that it’s still being mined.

10

:smack: As is often the case with any post by yours truly after midnight, I guess the water vapor released from a fuel cell cancels out any effects of “mining” it in the first place.

11

Biomass
Waste to energy
Hydroelectric
Nuclear
Nuclear Fusion (research - not here yet)
Geothermal
Wave generators
Current generators
Solar panels on the moon - sending back microwave energy (again not here yet)
And my personal fav.
Sentencing prisoners in terms of kilowatt hours instead of time and give them an excercise bike hooked up to a generator in their cell.

12

My point is that there is no hydrogen gas available in nature. All the hydrogen atoms are bound up in stable molecules like water, and it takes energy to rip off the hydrogen atoms from such molecules. When you later burn the free hydrogen as fuel, you are merely recovering the energy you initially used. So hydrogen might be useful for energy storage and transport, but it’s not a source of energy.

Anyway getting back to the OP, ethanol is another big controvarsial topic. (I guess that falls under “biomass” which kanicbird mentioned.) And a perfect example of how there’s not always a straight answer. Check out the discussion here:

13

Oh come now. Aside from being a silly distinction about what counts as “alternative”, the essay doesn’t ask for “true alternatives”; it asks for alternatives to fossil fuels. Fission even fits the bill.

14

Keep in mind there are energy vessels and there are fuels. They are not the same. Many people confuse the two.

A fuel “pays for itself,” in that you are able to extract more energy vs. what you expended to obtain it. Examples include oil, natural gas, coal, hydroelectric, and nuclear.

An energy vessel does not pay for itself; you expended more energy vs. what you get out of it. Examples include solar power (PV arrays), electrochemical batteries, hydrogen, and alcohol. While an energy vessel may work fine for a particular application (e.g. solar-powered calculator), it cannot be considered for use as a large-scale power source.

In order for it to be viable, you must prove a proposed “alternative energy source” is a fuel, not an energy vessel.

15

I think it’d be great to hear the role of nursing in alternatives to fossil fuels. Why not try that?

16

While it’s true that, with the current level of technology, solar panels are effectively energy vessels (that is to say, it takes more energy to manufacture one than you get from it over the lifetime of the device), there’s no reason in principle that they could not become true energy sources, given advances in technology. I suspect that solar power will become practical well before fusion does. And for that matter, I wouldn’t rule out fusion power, either. Once the technology is developed, fusion will be sufficient to provide all of humanity’s power needs, for a period of time which you might as well call “forever”.

Ultimately, every power source you find is going to come down to solar, fission, fusion, or geothermal, and for that matter, geothermal is ultimately fission, and solar is ultimately fusion. Most power sources on Earth trace their origins to the Sun: Fossil fuels and other biomass get their energy from plants, which got it from the Sun, and weather (wind and hydroelectric generation) derives from differences in the rate the Sun heats different parts of the Earth.

17

Sure there is. Most commercially produced hydrogen does not come from electrolysis of water, it comes from natural gas through a process called steam reforming:

Now if you are going to argue that this process for producing hydrogen doesn’t qualify as “naturally occurring”, may I remind you that by that standard, there is no gasoline available in nature either??

18

Nitpick ; it provides 75% of France’s electricity, which isn’t the same thing at all. Our cars don’t use nuclear engines, for instance.

19

[hijack]
It’ll produce a group of super-fast criminals!
[/hj]

20

Not really an energy source. Just a medium. Can be useful for concentrating pollution outside urban areas, but not for energy production.

-Wind
[/quote]

Solar and Wind have essentially the same problem, albeit represented differently: cost to performance. Both are simply too expensive, too picky with regards to location, and too expansive to be a real souce of power. You can get a little bit of juice around the edges with it, but solar cells are just too expensive and those giant towers for windmills are too expensive and only work in a few places. Useful in Holland, but not al over the place.

The big problem with this is the cost of transit. If all that biomass was just sitting in a pile, it’d be great. But its not. You have to send out fleets of collecters and trucks to move it in. It might turn a small profit, but its just not cost-effective to run a society off of it.

A good one, true. Sadly, the US has really used up its readily available hydro power sources. Its just a limited form of power.

Probaby the best choice. Our reactors are extremely safe, productive, and non-polluting. And yes, I meant that last one seriously. Yeah, there’s a slim chance someone might get exposed to radiation, but its nothing compared to the daily risk from air pollution.

Promising but still an unknown, since its nonexistant as of yet.

Another useful but limited form, like Hydro. I think we’ve pretty much tapped this out in the US.

Don’t know too much about these, though I here Iceland has had some fun with 'em. But I bet they have the same scaling problems and limite location problems.

Ah yes, I loved these from Simcity 3000…