Solar Versus Steam Power

Steam power is not really efficient because it demands a lot of water or any other kind of liquids. The power of energy off of the sun and moon is more common now or almost is. Things have been able to go solar/lunar powered. Why? Because there is always a sun and a moon. Event though you can't see it, the moon is still there. I doesn't always have to shine to power anything lunar powered.

I hope this helps. Good luck!

"If you really want to kill me, then hate me, detest me, and cling to life. Run and run, train and train, and maybe one day...you will kill me." -Itachi Uchiha

"Lunar powered" is, while an interesting idea, really not going to fit the bill in terms of being plausible. The amount of light that the moon reflects back to Earth, even at the full moon with a cloudless sky, is a tiny, tiny fraction of what the sun sends down to Earth even on a totally cloudy day. The only other way to get energy from the moon would be through its gravitational attraction, which is what powers the tides. There are certainly lots of people looking into and developing tide- and wave- powered electricity generation but that's obviously not going to work for cars.

Solar is, even today, probably better than you think. There's a lot of work going on in this area right now, on developing new kinds of solar cell materials that operate at higher efficiencies than polycrystalline silicon solar cells (the "ordinary" kind). You can plausibly hand-wave that in however many years your novel is set into the future, that this problem has been licked. I wouldn't blink an eye at the notion that, in 30 years' time, technology had been developed to the point that a car's entire surface acted as a high-efficiency solar cell (say, 50 to 75% efficient). Arguing that, on a sunny day, the car would have access to a steady couple of kilowatts is probably justifiable. Now, how many kilowatts you need to make the car perform at a satisfactory level, that's another question that I'm not really equipped to answer. My guess is that cars would still need to have big battery systems they used to store solar energy while they were parked, in order to boost the amount of energy available while driving.

If you don't mind burning some sort of fuel to generate sufficient heat, you can go with steam, too. Just make it a closed system, where the engine recycles its steam back into water in a loop. Done right, this would arguably make for a MORE efficient steam engine because the incoming water would already be really hot, close to boiling, so it wouldn't take as much additional energy to re-boil it for the next piston cycle. But., with steam, you're still talking about needing a beefy heat source, which probably means fuel.

Unless you want to combine the two technologies, and go with a solar/steam hybrid, where the solar just exists to charge up a battery so there's enough energy to heat up the coils that boil the water. My guess is that you'd end up with a car that worked, but was very slow to start up and get up to speed.

Given what Tesla Motors is already doing with high performance electric engines (0 to 60 in less than 4 seconds), I'd say your most plausible line is to go with a solar-skin version of the existing plug-in Tesla. (http://www.teslamotors.com/)

Crashdown (YA sci-fi / horror)
Stranded on an alien world, Ruve must deny his own humanity in order to survive. To get home, he'll need the help of someone back here on Earth. If, that is, he can convince anyone here that he's real.

Compressed air for several reasons has a much greater potential than most people realize. It can be easily compressed by a multitude of processes, from the most basic mechanical designs to the most sophisticated. In an accident, there is no 'fuel' to catch on fire, and while there is a valid concern regarding the pressure tanks, it still is not on the same level as an exploding gas tank. No 'fuel' is used while stopped. It lends itself to regenerative braking systems so slowing down and stopping will replenish the supply to an extent. On starting the full power of the system is available, no 'revving' of an engine required, and no threat of stalling and killing the engine. It is environmentally friendly - depending on the method of compression. Energy, supposedly lost to the environment upon compression, is freely reclaimable back from the ambient environment if the system routes the compressed air from the tank through a simple heat exchange system. This is not new technology although new technology helps make it better.

My people have developed personal fusion generators. Two stage process, involving three catalysts that only need to be replenished every five years or so. System pulls hydrogen out of atmosphere to use as fuel, catalyzes it into fusionable hydrogen, then catalyzes it into a fusion reaction. The generators are too powerful for a car, but they power maglev trains and any large equipment. They power entire buildings and people plug their cars into the building to charge their fast-charging, slow drain, capacitor-based vehicles.

You could miniaturize the device even more to power an individual car. My people didn't, because they switched most transit to maglev, downplaying personal transportation.

No radioactivity, no chain reaction to get out of control. finally, Safe nuclear power!

Steam isn't really a power source. Steam is generated by burning other fuels to create heat - the obvious problem there is that you need a fuel source.

In the case of solar, the sun is the fuel source; in a car this is generally used to produce electrical current to drive a motor. A steam engine isn't that different from the plain-old internal combustion we already use, only it'd be a lot less efficient.

Biosolar Reactors. Sprawling desert and coastal (or even oceanic platforms) covered in transparent plastic spherical shells containing algae water. The farms are modular, scalable, and produce vast quantities of bio-diesel. Additionally, a carbon-credit market has developed, and the energy companies are able to supplement their revenues and drive down the cost of the fuel by selling them to power plants and heavy industry that still consume plentiful coal. As a result, biodiesel was able to compete with and overthrow crude oil. As a downside, "pre-oilgae" cars are unable to find cheap fuel and were bottlenecked out of existence, shaking up the automotive industry as well. On the plus side, renewable, on demand, easily transported, and easily stored fuel is cheap and plentiful. The USA is an oil exporter, and the price of oil is pretty stable, with production rising to meet demand.

Thanks for the ideas and input, everyone. Now I have some thinking to do.

This is actually very interesting. Having the cars/trucks run slowly would actually work in my novel. I just wanted to make sure that the combo of the two would at least sound plausible.

Thanks again, and if anyone has any other suggestions, please keep 'em coming!

Solar really isn't practical for an industrial society. There just isn't enough energy in sunlight striking the earth (1 kilowatt per square meter). Even at 100% conversion, you're still paving over miles and miles of land.

Your best bet for 50 to 75 years in the future is nuclear fission for large scale power generation and nuclear isomers for small scale power storage.

Read up on it here: http://en.wikipedia.org/wiki/Nuclear_isomer

Tanstaafl

Yeah,been wondering about compressed. There's also the notion of liquid air for vehicle propulsion. You also get free A/C! One developer burns fuel in the air stream, which gets added power.

Wonder about putting compressors on wind turbines instead of generators. Let the generators run on compressed air. So you have the storage for production and demand fluctuations.

As for trucks and other motor vehicles, Electric is progressing rapidly--both the batteries and the motors.

I've been fascinated by slot racers. Remember them? Essentially a "third rail" that provides power, steering, and speed control. Run the trucks on dedicated roadways with the slots. Charge the batteries while on this roadway. At destination city, retract the probe that goes into the slot, and the driver takes over as the truck proceeds to the warehouse on batteries.

Compressed air has serious safety issues. Think dry ice bomb on steroids. Seriously. In order to get any kind of real power out of compressed air, you're talking tens of thousands of atmospheres of pressure. If the container fails, your car just turned into a giant ball of shrapnel shredding people and just about everything else for a couple hundred of feet in all directions.

Electric motors are highly efficient and have been for decades. Chemical batteries, however, slam up hard against the laws of physics. There's only so much power you can get out of chemical batteries because of the nature of electrochemistry.

Your slot cars would be impractical on a large scale. However, you can run power lines through the roads and power your vehicles using induction. The problem with that is that anyone walking across your road with a set of keys in his pocket is going to get third degree burns from the heat generated as the keys move through the induction field.

The harsh reality is, if any of these alternatives to gasoline and the IC engine were practical and profitable, we'd be seeing them on the roads today (conspiracy theories about evil oil conglomerates notwithstanding).

The issue here is one of energy density. Gasoline is a wonderful portable energy source. It's easy to transport, burns well, but is not explosive and has a very good energy density (47 megajoules per gram).

Fuel cells are a possibility, although storing the hydrogen is a bear unless you are willing to store it chemically in a hydrocarbon like butane. Run the butane through a reformer to produce hydrogen gas and feed it into your fuel cells. Just vent the carbon dioxide. If you buy into the global warming CO2 is toxic shtick, have your butane created synthetically from algae or genetically engineered bacteria to keep it "carbon neutral."

Tanstaafl

Be aware that your concept of fusion is total handwavium, if that concerns you.

First, the amount of hydrogen in the atmosphere of an earthlike world is minuscule. Secondly, "catalyzing" hydrogen into a fusable form is meaningless.

Hydrogen forms three isotopes, common hydrogen, deuterium and tritium. Tritium is unstable with a half life of around 12 years and so is extremely rare naturally.

The only way to "catalyze" hydrogen into an isotope is to bombard it with neutron radiation, hardly a safe, non-radioactive process.

The easiest type of fusion to perform is dueterium-tritium fusion (D-T) fusion. This form of fusion releases hard neutron radiation while operating. Fortunately, the neutrons can be captured by Lithium to create tritium, so you can actually breed your tritium fuel as your reactor runs. You can also use it to make deuterium out of regular water (along with a bunch of other radioactive isotopes from the oxygen and other elements in your water).

This means that a running fusion reactor is quite radioactive, and can produce radioactive byproducts in the containment vessel during operation.

If you want to keep your book reasonably grounded in science, there's just no way to get around radiation as a byproduct in any nuclear process. But, on the flip side, grounding your book in science also means you realize that radiation isn't as dangerous as it's been made out to be. It's generally no worse than any other toxic waste produced by any other type of industrial activity. The more radioactive a substance is, the quicker it "cools". The really nasty stuff is only around for 6-12 months. After that it's all mid-level stuff you can seal in concrete, wrap in a barrel and shove in a cave somewhere, or dump in an ocean trench. After about 300 years, all that's left is stuff that's so low level, you'd be more at risk living in North Dakota or any other place with lots of granite.

Tanstaafl

Steam has been used to power cars for a long time. The Stanley Steamer broke the world speed record in 1906 at a speed of 127 mph, far and away ahead of anything else at the time.

But, as pointed out, some fuel is needed to boil the water. An endless supply of water is not needed, since the same water is cooled in a radiator and then returned to the boiler and used over and over. Efficiencies of 70 to 80% are possible--which is much higher than with internal combustion engines. (A steam engine is an external combustion engine.)

The trouble is that steam turbines get most of their efficiency while running at a constant load, whereas cars operate at a variable load, since they are constantly changing speeds. This can be resolved by using the steam engine in a hybrid mode, where the turbine drives an electric generator.

I used to work as a boiler operator in a large steam plant, with many steam turbines. We always preferred to use the steam turbines to drive pumps and fans, because the steam saved money over running the same equipment with electricity.