Since that awful day, I've felt we all need to make a great mental push to try and find alternate sources of energy. The reasoning being that many of our conflicts seem to revolve around economies needing oil to continue running. If we didn't need oil, we wouldn't fight to secure its flow, and the world would be a more peaceful place. Does that make sense?

No -- what a load of crap!

With the advent of modern agriculture in the 1800's, people no longer needed to fight over food, yet it resulted in the largest land grab in human history (including the farm I'm sitting on). Famine as a weapon has been fairly popular too. With modern transportation, people no longer needed to go raid horses, instead we made tanks and raided continents. With steam engines we harnessed so much cheap energy that even slaves weren't competitive. This spawned an incredible assortment of high powered meat grinders, each one better than the last. So then, thinking everything would be peachy if there was a endless supply of free energy, is, umm, pretty optimistic I guess. At best it would make invading cheaper, but surely it would be coaxed into blowing things up.

Clearly 'world peace' won't be invented, nor will mutual respect be battery operated.

I know what you are thinking though -- "but Robin, I have so much more respect for you since you got that new laptop". Well that is true, there is no question that people respect you more if you have cool stuff, and respect is obviously the foundation of all lasting peace. I guess in that sense, science could save us. Probably we could attain ten years of global harmony by getting everyone a super cool cell phone. And I mean like really sleek design, maybe a translucent case, and so uber compact that we couldn't possibly use it to club each other to death. Might be worth a try.

Ok, back to plotting our destruction. Basically there are two types of energies that we use. One is 'unlocking' energy that is inside something. Burning wood, coal or oil releases stored chemical energy, splitting an atom releases atomic energy. People like this type of thing because it scales well. If you want more energy, you just add more product -- it happens on your schedule.

The second category of energy harnesses potential energy differences that naturally get replaced. If you think of a kid sitting in a wagon at the top of a hill, obviously there is energy to be had in this situation. However, as we learn, once she gets to the bottom it takes just as much energy to drag the wagon back up the hill, so there is no net gain. Hydro dams work much like this, except nature kindly brings the wagon back up the hill for us, in the form of upstream rain. Wind power is replenished by nature bringing air back to the original side and blowing it against the props again. Tidal power, solar power, even food all work like this. Actually so do coal, oil and wood, however they also borrow the wagon for fifty to fifty thousand years, so it isn't really the same thing. This type of energy generally is harder to scale, as it is bound by the rate of replenishment. No matter how big your dam, you can't generate more electricity than the river volume (and lay of the land) allows. For this you need more dams. This type of energy also tends to require more space as you scale. We tend to think of this type as 'cleaner', however because the required area increases as it scales it can be a pretty destructive solution. Imagine covering the US midwest with solar panels for example, and then imagine cleaning this up when they wear out. Having lived near hydro dams I can attest that they aren't without environmental and human costs either.

The nice thing about the replenishable energy is that it can be very personal. A small windmill can pump water for cattle, but even if every ranch gets two, it's hard to imagine a way of getting all that power to wipe out a city. So it seems a sensible goal that one day everyone's roof tiles may be made of solar panels, and favorable hilltops are dotted with wind generators. Of course this would free up massive amount of energy for other beautiful purposes, so it could still be death by a thousand pin pricks. A thousand pin pricks an one thirty mile wide ion blast that is.

When thinking of such systems, what we really need to think of is ways nature will carry our wagon back to the top of the hill. If that can happen, we can generate energy off the difference. Nature pushes some things around in a fairly constant and predictable manner. For example,

• air (wind, typhoons, rising hot air)
• water (ocean currents, tides, rivers, waves, rain, glaciers)
• land (volcanoes, sand dunes, mountains, continental drift)
• denser matter (sinking oil tanker, rising oil slick, helium balloon)
• energy (lightning, fire, sunrays, sound, magnets)
• life (plant growth, hamster wheel, trip to fridge)
• big things (planets, moons, stars)
• small things (atoms, molecules, Belgium)

One thing that is continually intriguing is electrolysis. It is neat for a few reasons. Water is abundant, and is at the root of many current energy generations systems (like water mills and dams) because it is heavy and brought uphill by nature. It can be changed to hydrogen and oxygen, which will explode. Not only is it easy to generate useable energy from exploding water, the flash and loud bang really gives you a sense of being powerful and unstoppable. Third thing, is hydrogen gas is very light weight, so it can cause heavy objects to defy gravity. It also really expands -- 1 liter of water produces around 44,000 liters of hydrogen gas, and 22,000 liters of oxygen gas. Clearly a good thing that water doesn't make you fart. Surprisingly, it doesn't take much more energy to break down water under really high pressures.

There are a lot of potentials energies at play here, lets make a hypothetical system taking advantage of a few of them. Yes this probably wouldn't work in real life, as nothing is 100% efficient. However, the idea is that in a gas form, hydrogen floats, and when 'burned' the resulting water falls. In the animation below, nature is bringing a wagon of water up the hill for us - the hydrogen because it floats, and the oxygen because wind replaces it.

There are three forms of energy being utilized here; gravity rolls the cart down the hill, density differences bring it back up, and chemical energy is released when the hydrogen converts to water. The energy we input is the energy needed to break down water into hydrogen and oxygen -- if this was 100% efficient both ways things would be easy. But it ain't.

It would however be easy to do this at least a bit better, by increasing the differences. For example, while a helium balloon floats in air, it isn't about to carry away a small child. However, if you put that same balloon underwater, it has an incredible upwards force. One idea could be to take this underwater then. Going down is pretty easy, just make your machine out of iron and call it unsinkable. As it falls, props could cause the main body to spin one way, and an outer fan to spin another, generating electricity all the way down. Near the bottom it takes this electricity and by way of electrolysis, it fills some sort of balloon with hydrogen and oxygen gas. This causes the total density of the system to decrease, so it now rises (generating electricity all the way up). Once at the top, the hydrogen and oxygen are burned (to create a bit more energy), the energy is siphoned off, and it begins to sink again. If you had deep water, like say off the coast of California or Japan, not only would you get longer dives, but you would get immense pressure changes, which could also be used to generate energy (eg. conceptually like the pressure loading a spring or something).

These things could be self contained, only needing a station at the surface to capture the electricity. One station could handle many of them because of the delays between surfacing. Things like battery weight aren't an issue, because you want the bottom to be heavy anyway. There are no high tech materials involved, so it should be reasonably cheap to make. It would scale easier, because the 'surface' it takes up is underwater.

I realize this looks a bit like a 'perpetual motion machine', and of course they don't exist. I'll try to explain why I don't think so, and where the extra energy is coming from (and I may be proven wrong here). You can think of the electrolysis being neutral (minus efficiency loss of course, and a slight bit extra because electrolysis requires slightly more energy under very high pressures). The H2 and O2 really are just acting like a battery, storing energy from the battery in the gases. At the top, the energy is returned to the batteries. So the extra energy is something like the potential energy of a very large inflated rubber dingy sitting a few miles underwater, and maybe some extra if you can take advantages of pressure differences. If that potential energy is greater than the loss due to the inefficiency of electrolysis, then you should be getting extra energy.. Not sound? Please let me know, I'm no engineer : ).