Way out of the US fuel chrises?

Great Debates
21

[QUOTE=Public Animal No. 9]
Theoretically, there is not enough energy content in municipal waste to provide the energy needed to cover gasoline consumption in the US. The latest numbers I’ve seen are about 360 million tons of municipal solid waste per year in the U.S., at about 4,500 Btu/lb. That calculates out to be equivalent to about 72 million gallons of gasoline per day, compared to current consumption of about 380 million gallons per day.

However, it takes energy to collect the waste and convert it into useful fuel, so it’s not a 1:1 ratio. But that ignores the fact that the energy embedded in the waste is greater (sometimes significantly greater) than the energy you can get out of it. By “embedded”, I mean that it has taken a lot of energy to make the product that you use and get it to the store, and that energy is not included in the direct energy content of the waste. Over the full life cycle of the stuff we use and toss, it’s more likely that we are less than 5% efficient when we compare the total energy in the waste to what we would be able to squeeze into a fuel.

Sewage is even worse as a fuel feedstock. There’s really not that much of it, and it’s got relatively low energy content. Plus, it has to be dried before it can be used as a feedstock for gasification or other conversion to fuel.

The Department of Agriculture has estimated that the U.S. could harvest as much as a billion tons of biomass each year for energy production, without impacting agricultural output for food and fiber. Even if that were possible, and even ignoring the conversion issue, that still doesn’t get us enough energy to cover current gasoline consumption levels. With biomass, municipal waste, and sewage, you get about 270 million gallons of gasoline per day, if you could convert it without any further use or loss of energy. That still leaves 100 million gallons per day that need to be made up by reduced driving or increased efficiency.

Even at perfect conversion efficiency, we would need to increase our average mpg by over 28% to make it possible to be petroleum free, and in reality, the amount would need to be much higher to account for the losses and the increased energy needed to grow and collect all this stuff.

The problem with most of the “easy” fixes that people identify is that they can work very well on a small scale, but expanding them to national or global scales has tremendous impacts.
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Fascinating stuff, PubAn9. You seem well-informed.

At an optimistic 20% total conversion efficiency, this could only replace a small fration of the oil needed.

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[QUOTE=Public Animal No. 9]

The Department of Agriculture has estimated that the U.S. could harvest as much as a billion tons of biomass each year for energy production, without impacting agricultural output for food and fiber.
[/QUOTE]
When you add bio-diesel from algae it would be real easy to meet the energy needs for transportation. It’s already a reality. And a company called Valcent Products thinks its possible to grow 100,000 gallons per acre. Read here. check out their video.

This is the kind of research we should be handing to our universities.

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[QUOTE=Magiver]
When you add bio-diesel from algae it would be real easy to meet the energy needs for transportation. It’s already a reality. And a company called Valcent Products thinks its possible to grow 100,000 gallons per acre. Read here. check out their video.

This is the kind of research we should be handing to our universities.
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The universities are doing quite a bit of this work, and it does have promise. There are a few big “howevers,” however. Think of biofuel as merely a means of storing solar energy, because that’s all that is really happening. The US gets, on a daily average, about 250 W/m2/day of solar energy. Converting that to the same energy basis as gasoline (124,000 Btu/gal), each m2 of land area could, on average, give you about 0.165 gallons of gasoline per day, if everything were 100% efficient (which it’s not). The 100,000 gal/acre level would be about a 50% conversion efficiency from solar to fuel, which is probably unreasonable. My recollection is that photosynthesis is pretty inefficient in terms of energy conversion, although that’s definitely not something I know a lot about. You could certainly grow the stuff in places like the US Southwest where the level of solar energy is higher, but I don’t think it’s high enough to make a huge difference.

To meet US energy demand, we would need about 890 sq mi of land area, which isn’t a lot to ask. But again, that’s at 100% efficiency. Assuming something more like 5% (which is high) for the entire process, we would need something more like 17,800 sq miles, which is roughly the size of Vermont and New Hampshire combined, entirely covered with algae ponds. This is not too far off. An article about a recent study by Chevron and the National Renewable Energy Laboratory estimated that they could achieve yields of between 15,000 and 80,000 liters of biofuel per hectare per year. Converting that to gallons per sq mi and multiplying to get the 380 million gallons per day that we use gives you between 25,000 and 130,000 sq miles of land needed - which is about 0.6-3.5% conversion efficiency from the average solar. As you can see, now we’re starting to talk about a lot of area for fuel production.

Algae also uses a lot of water - roughly 1000 times as much water volume as algae volume. If we estimate the volume of algae as being the same as the volume of fuel (which is low, but a relatively decent starting point), then we would need about 140 trillion gallons of water to grow the stuff. That would cover the entire state of Florida with more than 10 feet of water. That amount of water is worth about 115 days worth of the Mississippi’s average flow - it’s a lot of water.

Fortunately, algae doesn’t require nice, pure water, so that would reduce the cost somewhat. But I expect that producers would not want to introduce any sorts of algae-killing bacteria or other nasties into their fuel production system, so some treatment would be needed.

I’ve used the US consumption of gasoline as the basis for my numbers, but algae is used to make biodiesel, so we’d either all have to start driving diesel vehicles or we will need to convert the diesel to gasoline.

In any case, this little back-of-the-envelope calculation ignores much of the energy that will be needed to operate the facilities, pump the water, and get the fuel to the filling stations. That’s not going to be trivial, either.

I may be off on some of my calculations, but the bottom line with all of these is that we use a LOT of gasoline, and anyone who tries to sell you a quick fix is either unaware of the magnitude of the problem or is trying to take you for a ride. All of these approaches are worth looking into, but they’re not going to fix the problem on their own.

I certainly wouldn’t characterize this as “real easy”.

(edited to correct a wrong value)

24

Subsidize those little caps drivers can put on their tire valves to make sure the tires are fully inflated, to the point where drivers get them at cost or free, and maybe make them standard on new vehicles. That should save a few gallons.

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[QUOTE=Bryan Ekers]
Subsidize those little caps drivers can put on their tire valves to make sure the tires are fully inflated, to the point where drivers get them at cost or free, and maybe make them standard on new vehicles. That should save a few gallons.
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Dude, they’re like 4 bucks. The paperwork would cost more.

26

To the OP’s question:

As others have pointed out, mopeds aren’t terribly safe, aren’t an all-weather option. Also not much use for hauling groceries, taking kids to school, highway driving, long trips, etc. What they’re pretty good at is tooling around a city area you’re already in. If they were supplanting cars here, good, but you can see you are down to a greatly reduced usability population. And, I suspect that in many cases, when people are using mopeds, they are doing so in lieu of walking, or because there’s no good public transportation to get around the city. Mopeds are pretty popular in a lot of lesser-developed countries. Which is why a lot of cities full of mopeds are noisy, exhaust-filled, and a danger to your life to step off the sidewalk.

Contrary to the OP, coal is not going to run out any time soon (nor are other hydrocarbon deposits such as oil shale or tar sands, though jacking them out of the ground is not cheap and may get less cheap).

What all of this points out is that, up until now, it’s made an awful, awful lot of sense to use oil. It’s super-concentrated energy (unlike ethanol or hydrogen), it’s already there in free form (unlike hydrogen), it’s a portable store of energy (unlike a solar farm). I’m always bemused when the tree huggers scoldishly say “why did we allow ourselves to get hooked on oil?” Because it’s a darned good energy source, that’s why.

Failing to have a Plan B for when oil gets harder to recover (not runs out – that’s not going to happen soon), now that could have been questionable judgment.

27

[QUOTE=Public Animal No. 9]

I certainly wouldn’t characterize this as “real easy”.

[/QUOTE]
I agree. Easy may not be the case but it’s certainly doable. But you have to start looking at the world balance sheet. The technology would be easily exported. At some point the value of crude oil will plummet. It’s not like we have to completely replace oil producing countries. We just need to take enough demand off the table to nullify the high demand for it.

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[QUOTE=Cisco]
Dude, they’re like 4 bucks. The paperwork would cost more.
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I’m not sure we’re talking about the same thing - rather than a little plastic cap that covers the valve, I’m referring to ones that have a built-in indicator.

If I could get a set for four bucks (as opposed to thirty), I’d buy them immediately.

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[QUOTE=Huerta88]
Contrary to the OP, coal is not going to run out any time soon
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Cite for your false statement I said coal would run out soon?:dubious:

I said it was bad for the environment. Which it is, and it will run out someday. Which it will.

I’d much rather use domestic coal then be at the mercy of 3rd world countries who generally hate us. However it is a limited resource, just because it isn’t in the near future doesn’t mean it won’t run out.

To not account for that is doing the same bloody stupid thing the wankers that run our country did with oil to put us in this mess.

Public Animal No. 9 how do your numbers crunch with coal gasification?

Keep in mind with the goal of near immediate relief as possible that the US does produce a chunk of it’s own oil. IIRC like 20%

Scooters might not have been the best idea but would something like this as an option be so bad?

They currently can’t use the freeway, but I bet the design could be tweaked.

Long time ago I used to have a Geo Metro. Got 40 mpg, and could do the highway safely. Something between a 3 wheeler and Geo Metro could prolly get crazy gas milage, be suitable for Americans, highway appropriate, and cheap enough for people to get quickly. They have cargo and passenger room, you could even install doors. Motorcycles can be gotten for cheaper still and are highway legal.

A wide spread program to get high milage transportation in people’s hands could go a long way toward helping.

If people choosing to stick with SUVs turn out to be hazards to other motorists then they need to be regulated heavily to remove the danger, simple as that.

30

oh and I don’t know exactly how much oil is left in the world, but gas is over $4 a gallon.

Clearly we’re running low in the US.

31

[QUOTE=Bryan Ekers]
I’m not sure we’re talking about the same thing - rather than a little plastic cap that covers the valve, I’m referring to ones that have a built-in indicator.

If I could get a set for four bucks (as opposed to thirty), I’d buy them immediately.
[/QUOTE]
You’re not reading the site you posted correctly. They’re sold in pairs so it would be $15 for a complete set. They have to break them into pairs because front and back pressures are often different on cars.

32

I think that a lot of these ideas are good, in the sense that we should gradually work toward their implementation as they become cost effective, but I think that a system of subsidies as a whole is a terrible idea, and in many ways is a solution in search of a problem.

Part of the reason this plan fails is that I think that the problem to solve hasn’t been defined. Is the problem that gas is too expensive for American consumers? If so, this whole subsidy plan isn’t going to solve that problem. It’s going to be more expensive, overall. The reason I know that it is, is that if it weren’t, then people wouldn’t need subsidies. They’d already be buying the mopeds and converting their woodscraps.

Is the problem that the world, as a whole, is running out of oil? If so, then mopeds aren’t the way to go about solving it. Reducing our oil consumption is a good ide for lots of reasons, but it’s not going to slow the global use of oil. If oil were cheaper, other countries (China and India) would just use more. Oil is going to continue to be sucked from the ground as fast as it can be, and if we use a bit less, then others will use a bit more. The solution to this is to develop technologies that don’t rely on oil.

33

I’m sure like any simplistic suggestion, if it were that easy, we would have done it.

34

[QUOTE=riker1384]
Nuclear power and plug-in hybrid cars.
[/QUOTE]
Starting right now, it would take 20 years minimum to build enough nuke power to make a difference. Way, way way way too late.

35

[QUOTE=Bryan Ekers]
I’m not sure we’re talking about the same thing - rather than a little plastic cap that covers the valve, I’m referring to ones that have a built-in indicator.

If I could get a set for four bucks (as opposed to thirty), I’d buy them immediately.
[/QUOTE]

Either they have gone way up or that site is a ripoff. I got mine at the dollar store for $1 each. Granted, it’s been about 10 years . . .

36

Clearly I have to start frequenting a higher class of dollar stores.

37

[QUOTE=Askance]
Starting right now, it would take 20 years minimum to build enough nuke power to make a difference. Way, way way way too late.
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That’s the same response that’s been made for years over drilling for oil. We can’t solve all our energy problems by drilling therefore we won’t do anything. Fuel consumption went up so we just wrote a bigger check to oil producing nations who were happy to cash it and pump out more.

But while we’re here, how did you come up with your 20 year “minimum” estimate to build enough nuclear plants to make a difference.

38

[QUOTE=msmith537]
I’m sure like any simplistic suggestion, if it were that easy, we would have done it.
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I disagree. That’s like saying everything useful has already been invented. Not every idea has been tried or even thought of yet. Biodiesel from Algae has been in the research stage for years and is just starting to make it’s way into production.

39

[QUOTE=Magiver]
I disagree. That’s like saying everything useful has already been invented. Not every idea has been tried or even thought of yet. Biodiesel from Algae has been in the research stage for years and is just starting to make it’s way into production.
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It’s not even close to real production, but is still in development. It may be past the fundamental research stage, but that’s still a long way from full-scale production that will make any meaningful difference. The Chevron algae fuel program that I cited in an earlier post noted that they would be able to achieve between 15,000 and 80,000 liters per hectare yield. If you can’t determine your output within a factor of 5, you’re nowhere near being ready for commercial production.

The major obstacle to this, and to all the other ideas, isn’t whether or not they will work. Most of these concepts do work. The problem is scale. When you have to provide a bit more than one gallon per day for each person in the US - not just each driver, but each person - the logistics and infrastructure needs become incredibly difficult to overcome. It will not be easy, and while there are almost certainly going to be new ideas and applications, those will not be easy to put into practice, either. There probably will be some easy answers for individuals and a few companies or towns. But nationally or globally, it’s going to remain an incredibly difficult problem, unless there is some fundamental breakthrough on batteries, power production (like fusion finally works), and so on.

40

Mopeds produce a lot of particulate emissions, don’t they?

Put my vote down in the nuclear plants/electric cars/hydrogen fuel cells column.

The advantage of nuclear is that it addresses both our oil problem and our emissions problem.