Renewable energy and fuel

I did some back-of-a-napkin math on information I’ve gathered and have solved the world’s problems in one deft stroke!  Well, maybe not, but I have some interesting conclusions based on Wikipedia and some quiet reflection.  Remember, I’m not affected by political idiocy; if what I’m shouting doesn’t make sense, I don’t really want to shout it, because I’ll get proven wrong and I fucking hate being wrong.  So, yeah, if you see some dumb shit in here you might want to bring that up to me, it helps; but I’m for the most part pretty sure on all that follows.

First off, what the hell do we pour in cars?  Anything that comes from so-called “Fossil Fuels” breaks this exercise:  we believe (possibly correctly) that oil, coal, and other garbage we dig out of the ground and burn are all non-renewable.  I’ll agree with this, although I want to point out that I don’t think they’re the dead remains of rotting dinosaurs… it doesn’t make logical sense, when oil can be formed by heating and pressurizing hydrocarbons, like the propane gas that comes out of volcanic vents; still, my proposed process resembles the creation of diamonds, and we know diamonds as a fuel source (if it were possible) would quickly run out.  Use your brain for two seconds, it makes sense, oil forms pretty fucking slowly.

So our options have to involve something we can make without oil.  This means we need something that acts as a fuel, and derives its energy either at 100% efficiency from the local environment or works off the power of the sun.  For the benefit of most readers (even the smart ones, who probably don’t think all that much despite being able to grasp some of these basic concepts easy enough), I’ll point out that the heat inside the earth comes from spinning molten metal, which spins due to the interaction of the earth’s orbit with the sun’s magnetic field (this also creates the magnetosphere); that tides come from the orbit of the earth and moon; and that a lot of outside factors involving orbit, gravity, and sun shine affect the winds and weather.  Basically, if it moves or gets hot, blame the sun.

Well let’s start with so-called biofuels.  Biofuels derive energy from the sun by way of photosynthesis to create sugars (plant fibers are sugars; fiber is a long sugar chain, starch is a branching sugar chain).  Some lesser amount of energy can break this down–hence digestion, burning, etc–releasing solar energy back into the environment later as heat (animals get hot, and move).  Biofuels thus allow us to generate power in some form, mainly heat energy to crank a steam or internal combustion engine, which in turn can move a car or generate electricity.

Biofuels can generate enough energy to sustain themselves:  you can use the biofuels generated to fuel the refining process to generate more biofuels from the basic act of farming to the final act of packaging the fresh biofuel and reflowing a portion of it into the fuel input of the whole process.  Although corn provides a popular example, switchgrass gives even better returns; we will use this.

Switchgrass requires half as much energy as corn to produce and refine, and produces more output energy:  1 unit input energy produces 1.28 units output energy generating corn ethanol (i.e. after reusing the product to fuel the process, you retain 28% of the refined fuel), while switchgrass generates 5.4 units per 1 unit input.  Switchgrass also can be used as compressed pellets similar to coal or wood, yielding almost 15 units of energy per 1 unit put into the refining process; and a refinery can burn the remainder of switchgrass mass after extracting ethanol (i.e. “waste product”) to produce enough energy to continue to operate said refinery.  Switchgrass thus would be about 50 times better than corn for this sort of thing.

We can produce 340 liters of ethanol per tonne of dried switchgrass, and 400 liters per tonne from corn.  We can produce about 5 tonnes of switchgrass per acre in a year, or 1700 liters, or about 450 gallons.  It would take about 100 million acres of land to produce 25% of the nation’s energy need, says the University of Tennessee; we have 800 million acres.  That is, of course, a freaking lot of land!  400 million acres!  And it competes with food, which is never a good thing.

The lucky thing for us, of course, is the sheer flexibility of switchgrass:  we can compress it into pellets and use it in coal power plants, with or without extracting anything (i.e. sugars for ethanol) from it first.  Coal comes from stuff that’s been locked away in coal for a long, long time; switchgrass comes from the air, and the sun.  Burning switchgrass has the carbon footprint of eating a plate of broccoli:  we just took this stuff out of the air, it’s not new, the net carbon impact is zero and the environmentalists are happy.  Actually, we can use the ash left behind as fertilizer to grow more switchgrass, without putting it back in the air right away.

This probably works for bioethanol easy enough, which can run in gasoline cars (with consequences, if the fuel system has any aluminum parts); but I’d rather use the stuff to generate power wholesale, keeping the process simpler and the fuel denser.  Compacting unspent switchgrass will get you a pellet that burns hotter due to more available energy (sugar forcibly broken down by fire–wood works the same way, made of fiber, made of sugar), which we definitely want.  Besides, you don’t want half the available farmland in the US tied up making fuel, before you even get to planes and huge ocean tankers; we need an alternate alternate fuel source.

Biofuel encompasses any biodiesel, bioethanol, biocoal, or whatever else you want; so now we have to rely on either crude petrol (which we’ve already established as equivalent to burning diamonds) or something else, something electricity based.  Electric cars have too many problems to list–complexity, efficiency, energy storage, performance (yes, in the magic land, we like to imagine a Ford Mustang would go 200 miles with 450HP and 400ftlb torque the whole way on a charge, but it won’t; by the way, horsepower is a flawed way of measuring actual performance)–so let’s stick with internal combustion engines.

With no biodiesel, diesel, or gasoline, we only have hydrogen to fall back on.  In the narrow perspective, hydrogen represents an amazing renewable resource:  we can generate it from water, and it burns into water, with no nitrogen, NOx, hydrocarbon, CO2, or CO emissions to go with it.  That’s right, no emissions.  Pumping water vapor into the air constantly would fuck up the environment, so you’d definitely want to have a condenser in the exhaust to just pour water out the tailpipe; use a separate radiator and cooling system that doesn’t encounter engine heat for this, and you’ll be just fine.

Now how do we get hydrogen?  That takes electricity and a fairly inefficient process, although we can use various catalysts and electrolytes to reduce the activation energy and make the process more efficient.  At any rate, we need a decent, non-biofuel solution for generating massive amounts of electricity.  Yeah, sure, switchgrass pellets replace coal; but we can’t generate enough switchgrass to generate this much power.

Let’s try something benign first, like solar power.  Solar power requires some amount of space and a solar collector array; first problem, this competes with space for growing switchgrass, unless the land is horribly unsuitable for farming (switchgrass will grow in places corn, wheat, and other such food will not).  If we could line roofs with solar panels we could do it, but that becomes a nightmare because of business models, maintenance, and costs; I do have a business model for this sort of thing, though.

Second problem of course is that we’re collecting more solar energy than normal, and converting it immediately to heat (electricity, which gets used for work, which makes things hot); plants usually introduce a delay and slow bleed here, and parts fall off and get reused in other plants.  In this way, solar acts like fossil fuels that skip the fossilization stage (but then, so does burning plant matter i.e. switchgrass), in terms of energy release.  This puts more ambient heat into the earth’s atmosphere, directly raising the global temperature, causing global warming.

We could try for tide or wind power, with various environmental concerns.  Both of these rob motion energy from the surrounding fluid (water or air, respectively), changing the habitat and weather in the area.  Too much wind power would mess with the weather; too much tide power could alter the oceanic ecosystems and possibly mess with the weather by means of messing with ocean currents.  It’s somewhat more sane on the small scale.

Geothermal power works just about the same way:  plug a super alloy into something hot (volcanic vent), conduct through a sterling engine or thermocouple into something cold (lake), and get motion or electricity.  At the same time, you are drawing heat into a body of water, possibly altering the local ecosystem; on a huge scale, you could heat up the oceans somewhat, release some CO2 into the air and alter the thermal properties of the ocean currents, causing some drift.  I’m not even sure a large scale implementation of this is even possible though.

Nuclear power is fossil fuel based.  Do you really think uranium comes from anywhere different than coal?  It’s a shiny rock we find in the ground, that eventually replenishes from meteors or volcanic activity drawing it out of the center of the earth; tons and tons of this shit isn’t popping up all over the planet all the time, it takes something major to make more.  To make matters worse, we can only derive 5% of the energy potential from nuclear fuel without breeding it into weapons grade nuclear material (and then summarily using said weapons grade nuclear material for the non-weapons purpose of generating 20 times the electricity we normally could), which of course violates a treaty or two.

Hydroelectric power is a nightmare too; damming up a river tends to create issues, blocking the travel of marine life and altering the landscape on one side or the other.  Unless you do it at a waterfall anyway, then you can engineer it to act a little different.  Still, not typically viable in terms of minimal environmental impact; but of course, this environmental impact happens to be rather direct, and something the local species will route around (evolution, changing habits, etc.), so mainly benign.

I’m not sure it’s technically possible to generate tons of electricity without deriving it from ambient energy (wind, tides, etc) and creating a ton of extra heat sources all over the planet (hot solar arrays, hot wires, hot electric machines).  Pretty much any source of “clean energy” is going to cause a lot of thermal pollution, raising the global temperature of the planet if we keep it up–never mind putting CO2 in the air by burning oil, we’re doing all the cooking ourselves!

Oh well, whatever.  I think biofuels for cars is unsustainable, and electric cars are impractical.  Hydrogen becomes the only viable fuel source for cars; but how do we get it?  What we need is a self-sufficient space terrarium ….

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~ by John Moser on May 8, 2009.

 
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