3 ms·

What about micro-fuel cell + hydrocarbons? The energy density of gas/petrol is fantastic. Recharge time is quick ("pour some in"). http://www.gizmodo.com.au/2

by jbert 15y ago

What about micro-fuel cell + hydrocarbons? The energy density of gas/petrol is fantastic. Recharge time is quick ("pour some in"). http://www.gizmodo.com.au/2011/12/a-gallon-of-petrol-can-power-an-iphone-for-20-years/ http://www.gizmodo.com.au/2011/12/a-gallon-of-petrol-can-pow... http://www.mtimicrofuelcells.com/ http://www.mtimicrofuelcells.com/ Sure, we have limited supplies of hydrocarbons in the ground, but to me the key energy technology would be "synthesise hydrocarbons from water + CO2 + energy in". i.e. stop focusing on hydrocarbons as a source of energy and start thinking of them as a 'transport' of energy. That would also mean we can move to clean, renewable power generation without retooling the globe's transport fleet.

bh42222 15y ago
My understanding is that hydrocarbon using fuel cells run hot, really, really HOT. Which is why they are regularly used in race cars, but not in many other places.
- colinshark 15y ago
  They share names, but racing fuel cells are just small tanks.
  - Daniel_Newby 15y ago
    Tough tanks, filled with foam so that leaks are slow.
karamazov 15y ago
I had the chance to analyze a solid-state gas engine a few months ago, based on this technology: http://web.mit.edu/newsoffice/2011/sun-free-photovoltaics-0728.html http://web.mit.edu/newsoffice/2011/sun-free-photovoltaics-07... The solid-state engine has much lower efficiency than a regular power engine would (a hypothetical 12%/realized 5% vs. a realized efficiency of about 30%), but it can be made much smaller - and even at a 5% conversion rate, the energy density just blows everything else out of the water. Aside from being energy dense, it's also much cheaper than high-end lithium-ion batteries; and unlike regular fuel-cells, the technology is just based on regular photovoltaics, and is relatively easy to manufacture.
- jbert 15y ago
  Awesome, so we'll have the tech to consume the hydrocarbons, but where is the production side? What do we need to be able to hook up a nuclear power plant, a supply of clean water and a big air pump and starting sucking in H2O+CO2 and piping out CnH(2n+2) and pumping out O2?
- robocat 15y ago
  So at 5% efficiency, a solid state engine in a battery form factor in my cellphone is going to need to get rid of approx 20 times the Watts used... Hot :-)
mbell 15y ago
The energy density of hydrocarbons may be high but the thermal efficiency in most applications is horrible. Gasoline automobile engines are only about %20 efficient for example.
aaronblohowiak 15y ago
>"synthesise hydrocarbons from water + CO2 + energy in" I believe this is called photosynthesis.
- jbert 15y ago
  Yes, but the process then becomes biofuel, which also soaks up land area and has other issues (warping world food prices). It would also be nice to be able to capture the energy output of other energy sources, e.g. nuclear in a nice, energy-dense liquid form.
  - aaronblohowiak 15y ago
    Using food for fuel is dumb, I concur. I'm a fan of algae.

by jbert 15y ago

bh42222 15y ago

My understanding is that hydrocarbon using fuel cells run hot, really, really HOT. Which is why they are regularly used in race cars, but not in many other places.

colinshark 15y ago
They share names, but racing fuel cells are just small tanks.
- Daniel_Newby 15y ago
  Tough tanks, filled with foam so that leaks are slow.

karamazov 15y ago

I had the chance to analyze a solid-state gas engine a few months ago, based on this technology: http://web.mit.edu/newsoffice/2011/sun-free-photovoltaics-0728.html http://web.mit.edu/newsoffice/2011/sun-free-photovoltaics-07... The solid-state engine has much lower efficiency than a regular power engine would (a hypothetical 12%/realized 5% vs. a realized efficiency of about 30%), but it can be made much smaller - and even at a 5% conversion rate, the energy density just blows everything else out of the water. Aside from being energy dense, it's also much cheaper than high-end lithium-ion batteries; and unlike regular fuel-cells, the technology is just based on regular photovoltaics, and is relatively easy to manufacture.

jbert 15y ago
Awesome, so we'll have the tech to consume the hydrocarbons, but where is the production side? What do we need to be able to hook up a nuclear power plant, a supply of clean water and a big air pump and starting sucking in H2O+CO2 and piping out CnH(2n+2) and pumping out O2?
robocat 15y ago
So at 5% efficiency, a solid state engine in a battery form factor in my cellphone is going to need to get rid of approx 20 times the Watts used... Hot :-)

mbell 15y ago

The energy density of hydrocarbons may be high but the thermal efficiency in most applications is horrible. Gasoline automobile engines are only about %20 efficient for example.

aaronblohowiak 15y ago

>"synthesise hydrocarbons from water + CO2 + energy in" I believe this is called photosynthesis.

jbert 15y ago
Yes, but the process then becomes biofuel, which also soaks up land area and has other issues (warping world food prices). It would also be nice to be able to capture the energy output of other energy sources, e.g. nuclear in a nice, energy-dense liquid form.
- aaronblohowiak 15y ago
  Using food for fuel is dumb, I concur. I'm a fan of algae.