Alternate fuel question

[Titan]

I guess this is my hippie eco-fuel question.

Say I were to build a car powered by electric motors, like a golf cart but bigger. What would be the most efficient way to convert some kind of chemical fuel into electricity for the motors? Is burning fossil fuels to generate electricity the only practical way to generate that kind of power efficiently (without lots of weight)? Or is there some process involving a reaction that could do the job? I'm ignoring cost as part of the question for now.

 

[Mark R]

You want a fuel cell. The most efficient fuel cells run on Hydrogen. Depending on the technology used in the fuel cell, you'll get between 60 and 75% of the energy out as useful electricity.

In practice, you'd be lucky to get more than 60%, because the high efficiency cells need to be warmed up to about 800-1000 °C - hardly suitable for a car.

There are now modern fuel cells, which can run on liquid fuels like methanol or gasoline. The efficiency of these is much lower (about 40%). In fact, by the time you've taken that 40%, run it through an electronic control system, and the motors - you'll be down to about 32-35%. A diesel engine would, arguably, be more efficient.

Fuel cells are light, and compact - but current cells are expensive (between $2,000-$5,000 per horsepower, and wear out quickly - estimated at 10,000 miles).

Whether you use fuel cells or not, doesn't imact on whether you need fossil fuels or not. There are non-fossil ways of generating hydrogen, methanol and fuel oil.

 

[PowerEngineer]

Mark's right that there are non-fossil sources of energy, and they can work for you as long as you continue to ignore costs. (Takes me back to the hydrogen thread...)

I'd suggest, however, that you consider converting your house to non-fossil energy first. Solar heating for hot water and space heating; solar cells or wind generator for electrical power. If you can generate more electricity than you need for home use, then consider using the excess to charge batteries in a hybrid car or a fully electric (battery) car (if you have a lot of excess).

I'd stay away from fuel cells until the technology matures.

Good luck!

 

[Titan]

Duh, why didn't I think of Fuel Cells. I mean, I did, just had to get there in my own way. I was ready to call my idea "whoozigiggits!." Reading up on them on Wikipedia now. Man, I wish I didn't have to work and could just sit around and read Wikipedia for like a year. I just reached the age of reason, understand how the world works and have so many more questions to ask.

 

[Titan]

Originally posted by: PowerEngineer

Mark's right that there are non-fossil sources of energy, and they can work for you as long as you continue to ignore costs. (Takes me back to the hydrogen thread...)

I'd suggest, however, that you consider converting your house to non-fossil energy first. Solar heating for hot water and space heating; solar cells or wind generator for electrical power. If you can generate more electricity than you need for home use, then consider using the excess to charge batteries in a hybrid car or a fully electric (battery) car (if you have a lot of excess).

I'd stay away from fuel cells until the technology matures.

Good luck!

Thanks, it was more of a general curiosity question. I have been looking at solar but not sure if I'd want to try it in VT. On top of having less sunlight by living in a valley, we get long periods of clouds, I haven't seen the sun here in the past 8 days. I swear I'm not a ragin hippie, I just really like the idea of being self sufficient. It seems solar tech has improved in efficiency, but the longevity is an issue. I hear panels only last like 10 years or so.

Was thinking this past summer and had an epiphany about energy in this country. Hippies have problems with all alternate sources. Nuclear has radiation. Wind hurts the birds. Hydro/Tidal hurts the fish. Solar cools the deserts/jungles. So I realized where would the best place to put solar panels be? Roads. And Rooves. Think of all the miles of paved road we have in the US, and parking lots, and flat rooves in industrial parks. If we could find a cheap way to pave roads with a solar asphpalt or brick and connect it to a grid, we could get a lot of power. Imagine if it evolves and you drive to work and instead of cranking on the AC when you go back to it, it's already cool cuz when you parked and docked with the local grid and solar blinds covered your windows, and you even get paid for the juice your car generates. Then on weekends, all that space doesn't just sit there. Of course cost is a big issue. But tech has to be developed and mass produced. But how impractical would it be to make a solar brick, with 2 conductive cables in it to link to other bricks? This seems incredibly efficient, especially if we get somewhere with the tech to send data accross our power lines.

 

[SagaLore]

You could create a singularity, and hold it inside a containment field. Throw some matter into it and get back EM radiation.

 

[YoshiSato]

Originally posted by: PowerEngineer

Mark's right that there are non-fossil sources of energy, and they can work for you as long as you continue to ignore costs. (Takes me back to the hydrogen thread...)

I'd suggest, however, that you consider converting your house to non-fossil energy first. Solar heating for hot water and space heating; solar cells or wind generator for electrical power. If you can generate more electricity than you need for home use, then consider using the excess to charge batteries in a hybrid car or a fully electric (battery) car (if you have a lot of excess).

I'd stay away from fuel cells until the technology matures.

Good luck!

Plug-in-able hybirds are the way to go,(although they only exist in test enviromets)
This one scienctis converted his hybird into a pluginable hybrid by adding an larger array of batteries to his car and powers the batteries with power from his house. If he's batteris get low the engine charges them. He claims to get 250MPG.


This feature will cost about an extra 7 - 12 grand to the cost of the hybird

I think it may be eaiser and cheaper to convert an electric car into a hybird by adding a gasoline engine to a generator.

 

[Calin]

He gets 250MPG for short trips (as long as the car runs mainly on batteries). If he takes into account electricity costs, he is much less efficient, and if he chooses to make a looong trip, he will get lower MPG (based on the increased weight) than an original unmodified hybrid.

 

[Gibsons]

Originally posted by: Mark R
You want a fuel cell. The most efficient fuel cells run on Hydrogen. Depending on the technology used in the fuel cell, you'll get between 60 and 75% of the energy out as useful electricity.

In practice, you'd be lucky to get more than 60%, because the high efficiency cells need to be warmed up to about 800-1000 °C - hardly suitable for a car.

There are now modern fuel cells, which can run on liquid fuels like methanol or gasoline. The efficiency of these is much lower (about 40%). In fact, by the time you've taken that 40%, run it through an electronic control system, and the motors - you'll be down to about 32-35%. A diesel engine would, arguably, be more efficient.

Fuel cells are light, and compact - but current cells are expensive (between $2,000-$5,000 per horsepower, and wear out quickly - estimated at 10,000 miles).

Whether you use fuel cells or not, doesn't imact on whether you need fossil fuels or not. There are non-fossil ways of generating hydrogen, methanol and fuel oil.

What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

 

[SagaLore]

Originally posted by: Gibsons
What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

I thought catalysts themselves are actually inert - they cause reactions when other molecules are in proximity to them, but the catalyst itself maintains its original form?

 

[eLiu]

Originally posted by: SagaLore

Originally posted by: Gibsons
What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

I thought catalysts themselves are actually inert - they cause reactions when other molecules are in proximity to them, but the catalyst itself maintains its original form?

Catalysts are generally not destroyed in reactions. They're not reactants or products.

 

[networkman]

Originally posted by: Titan
I guess this is my hippie eco-fuel question.

Say I were to build a car powered by electric motors, like a golf cart but bigger. What would be the most efficient way to convert some kind of chemical fuel into electricity for the motors?

You're gonna need ALOT of potatoes. 😛

Seriously though, yes, the fuel cell is the better route.

 

[Gibsons]

Originally posted by: eLiu

Originally posted by: SagaLore

Originally posted by: Gibsons
What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

I thought catalysts themselves are actually inert - they cause reactions when other molecules are in proximity to them, but the catalyst itself maintains its original form?

Catalysts are generally not destroyed in reactions. They're not reactants or products.

Right, but over time, they don't necessarily stay where we want them to be 100% of the time or they could react with chemical X and lose their catalytic properties.

 

[Xyo II]

for all practical purposes, it is much easier and simpler to have a large set of batteries w/ an electrical motor. and at night, plug it in to an outlet to charge it: utilities burn a lot of fuel in the night that goes wasted because there isnt a a need for it then, so you are not upping greenhouse gases by charging it from your home.

 

[PowerEngineer]

Originally posted by: Einstein Element
for all practical purposes, it is much easier and simpler to have a large set of batteries w/ an electrical motor. and at night, plug it in to an outlet to charge it: utilities burn a lot of fuel in the night that goes wasted because there isnt a a need for it then, so you are not upping greenhouse gases by charging it from your home.

I'm afraid that is not exactly correct.

Fossil fueled power plants often have long, complicated (and costly) start-up and shutdown procedures that make it less expensive to keep them on-line over night when customer loads are relatively low. Power plants can't generate power than the customer loads require, and so during these low-load nights these fossil fuel plants have to generate much less than their maximum capacity. Most power plants are less efficient at lower output levels, burning maybe as much as 5% to 10% more fuel per megwatt-hour of electricity delivered.

Even so, the consumption of fossil fuel by a power plant (and therefore its production of greenhouse gases) is still roughly linear to its electrical power output. Charging up your batteries (or any other use of electricity) will produce about the same amount of greenhouse gases regardless of the time if it comes from a fossil fuel plant.

 

[potato28]

Go to Mcdonalds, get the left over oil, and convert ur engine to use it. Free fuel!

 

[PlasmaBomb]

Originally posted by: Gibsons

What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

Catalysts can be poisoned over time and therefore need to be replaced. Think about leaded fuel and catalytic converter on your car

 

[Woodchuck2000]

Originally posted by: YoshiSato

Originally posted by: PowerEngineer

Mark's right that there are non-fossil sources of energy, and they can work for you as long as you continue to ignore costs. (Takes me back to the hydrogen thread...)

I'd suggest, however, that you consider converting your house to non-fossil energy first. Solar heating for hot water and space heating; solar cells or wind generator for electrical power. If you can generate more electricity than you need for home use, then consider using the excess to charge batteries in a hybrid car or a fully electric (battery) car (if you have a lot of excess).

I'd stay away from fuel cells until the technology matures.

Good luck!

Plug-in-able hybirds are the way to go,(although they only exist in test enviromets)
This one scienctis converted his hybird into a pluginable hybrid by adding an larger array of batteries to his car and powers the batteries with power from his house. If he's batteris get low the engine charges them. He claims to get 250MPG.


This feature will cost about an extra 7 - 12 grand to the cost of the hybird

I think it may be eaiser and cheaper to convert an electric car into a hybird by adding a gasoline engine to a generator.

250MPG is a ridiculous figure because he's powering it primarily off the grid. It's like taking an electric milk-float and claiming that it reaches infinite MPG as it consumes no fuel. The increased weight will significantly drop his normal-use MPG and wear out his transmission and brakes faster. Once extra load on the grid and cost of producing the electricity he uses is taken into account, this is a <thoroughly> bad idea.

The best way of making a more efficient car is to go as light as possible. A small car with a diesel engine will hit over 70MPG in everyday use. I'd be surprised if the hybrid above managed more than 30 without external power.

 

[DrPizza]

lmao, I was reading the suggestion of putting solar cells on the road.
I had pondered the idea of covering a road surface with piezo-electric ceramics
(like the push button ignitors on gas grills)
Compress them to produce potential difference. A car driving down the road would compress a lot of them, potentially producing a lot of electricity. I figured out what was wrong with that idea though.

 

[Titan]

Originally posted by: DrPizza
lmao, I was reading the suggestion of putting solar cells on the road.
I had pondered the idea of covering a road surface with piezo-electric ceramics
(like the push button ignitors on gas grills)
Compress them to produce potential difference. A car driving down the road would compress a lot of them, potentially producing a lot of electricity. I figured out what was wrong with that idea though.

I'm glad someone bothered to read that part. Could you think of a better place to put them? Seems to make sense especially where the numbers of miles of road outnumber the people.

I was thinking a hexagonal brick with holes through each side straight through would allow wiring to go through would geometrically allow for decent power delivery, maybe along with data. They may have to be kinda deep though. Hell they could be motorized to collectively run new cable through them 😛

The biggest problem I see (besides cost) is finding a transparent surface that is still safe to drive on. Wet glass is not a good idea to drive on with rubber tires, right? Maybe we'd need new (more sticky?) tires that offer less heat and more efficient energy transfer?

Is there a low-cost solution for PV cells that have a decent (multi-decade) lifetime yet?

Or am I just a nut?

Edit: also, another problem I see is transformation. Since PV cells are most efficient in DC, and long-distance transmission is done best by high-voltage AC current. Still, it could be transformed with transformer stations, right?

Of course, I really like the idea, but maybe I'm too far ahead of my time, or someones time anyways.

 

[networkman]

Originally posted by: DrPizza
lmao, I was reading the suggestion of putting solar cells on the road.
I had pondered the idea of covering a road surface with piezo-electric ceramics
(like the push button ignitors on gas grills)
Compress them to produce potential difference. A car driving down the road would compress a lot of them, potentially producing a lot of electricity. I figured out what was wrong with that idea though.

Actually, I do recall reading an article with a similar concept, except that it was to replace the organic(grass) lawn with piezo-electric ceramics and having it do the electricity generation. You'd still get the desired landscape effect and not have to bother with mowing. 🙂 I think it was in Popular Science.

 

[Calin]

Originally posted by: eLiu

Originally posted by: SagaLore

Originally posted by: Gibsons
What wears out in a fuel cell? I'm guessing the catalysts need to be replaced(?).

I thought catalysts themselves are actually inert - they cause reactions when other molecules are in proximity to them, but the catalyst itself maintains its original form?

Catalysts are generally not destroyed in reactions. They're not reactants or products.

Catalysts are used in "intermediary" reactions - like you want to combine A and B. A and B won't combine easily, so you use the catalyst C.
The reaction now become: A + C -> AC, then AC + B -> AB + C
The catalyst is used in a part of the reaction, and "regenerated" in the other part of the reaction.

 

[MobiusPizza]

Originally posted by: Mark R
You want a fuel cell. The most efficient fuel cells run on Hydrogen. Depending on the technology used in the fuel cell, you'll get between 60 and 75% of the energy out as useful electricity.

In practice, you'd be lucky to get more than 60%, because the high efficiency cells need to be warmed up to about 800-1000 °C - hardly suitable for a car.

There are now modern fuel cells, which can run on liquid fuels like methanol or gasoline. The efficiency of these is much lower (about 40%). In fact, by the time you've taken that 40%, run it through an electronic control system, and the motors - you'll be down to about 32-35%. A diesel engine would, arguably, be more efficient.

Fuel cells are light, and compact - but current cells are expensive (between $2,000-$5,000 per horsepower, and wear out quickly - estimated at 10,000 miles).

Whether you use fuel cells or not, doesn't imact on whether you need fossil fuels or not. There are non-fossil ways of generating hydrogen, methanol and fuel oil.

However though methanol has much higher energy density than hydrogen and thus offsetting the efficiency difference betwixt the two.