4 ms·

For cars you are probably right. How does it look for planes, ships and even trains? Also, home heating. When can I buy something based on a fuel cell that wil

For cars you are probably right. How does it look for planes, ships and even trains? Also, home heating. When can I buy something based on a fuel cell that will let me replace my oil furnace? And there's the potential for buffering excess renewable energy. for now this problem can largely be solved by improving the electricity transmission infrastructure between countries, but it's unclear to me that this is sufficient in the long run. I dream of the Star Trek like future where the Earths energy is supplied from solar panels in the Sahara, generating hydrogen which is then shipped around the world.

PhantomGremlin 6y ago
solar panels in the Sahara Given the inefficiency of photovoltaic -> hydrogen -> liquid hydrogen? transport (how, not easy) It would probably be easier to create and ship LNG. At least we know how to do that. But you're much better off just putting 2x or 3x the number of solar panels in countries that don't have as high a solar irradiance as the Sahara does. Or even do HVDC from the Sahara to Europe. That is probably much higher efficiency than trying to use hydrogen or natural gas. BTW in case anyone is interested, here is a map of solar irradiance: https://en.wikipedia.org/wiki/Solar_irradiance https://en.wikipedia.org/wiki/Solar_irradiance
- glogla 6y ago
  It would work with Antimatter though! Even better to make it on Mercury than on Sahara.
  - TeMPOraL 6y ago
    On top of antimatter generation, we can also collect it in space, as it gets trapped in planetary magnetosphere. Antimatter harvesting works best in places with strong magnetic fields, which makes Jupiter and Saturn much better candidates ([0] claims Saturn is the best). Not sure how much we could capture in terms of mass/energy; the impression I get is that it may be worthwhile for space missions, but I'm not sure if it's enough to power a civilization. -- [0] - https://www.centauri-dreams.org/2016/08/03/antimatter-production-harvesting-in-space/ https://www.centauri-dreams.org/2016/08/03/antimatter-produc...
pjc50 6y ago
The standard answer for home heating is electrical-driven heat pumps.
- dzhiurgis 6y ago
  He makes a good point - fuel cell extra heat can go into house. Especially useful in places with no grid electricity.
- davewritescode 6y ago
  The problem is that solution doesn't scale to places where it's very cold. One reason electrical demand spiked in Texas was the fuel pumps stop working as efficiently as temperatures drop below freezing and most fuel pumps have coil backups which demand an order of magnitude more energy.
  - burmanm 6y ago
    Well, heat pumps extracting from air would function until -35C (at least some models), but obviously the efficiency goes down a bit. But most do a fine job until -20/-25C. For even colder climates, one can use ground source heat pumps. So this should not be a problem for heating purposes. Cheaper cooling designed heat pumps do not obviously function to so low temperatures, but all Nordic models for example will function just fine.
    - tzs 6y ago
      To put some specific numbers on it, Mitsubishi's "Hyper-Heating" heat pumps claim 100% capacity down to 23℉ (-5℃), and 76% capacity down to -13℉ (-25℃). This is for their ductless mini-split systems. Fujitsu is similar. Mr Cool makes the claim [1] that theirs "can heat at 100% capacity at –5 degrees Fahrenheit, even with outdoor temperatures as low as -22 degrees Fahrenheit". I think Mr Cool is talking about a central system, and so they are claiming 100% with the outdoor unit at -22℉ (-30℃) and the indoor unit, presumably in your unheated crawlspace, is at -5℉ (-21℃). Mr Cool also claims cooling with an outdoor temperature up to 115℉ (46℃), which so far is under the max for much of Texas, so heat pumps are a good choice still in Texas as long as you get one of the newer models with the good low temperature performance. [1] https://mrcool.com/blog/introducing-mrcool-universal/ https://mrcool.com/blog/introducing-mrcool-universal/
nickik 6y ago
> And there's the potential for buffering excess renewable energy. for now this problem can largely be solved by improving the electricity transmission infrastructure between countries, but it's unclear to me that this is sufficient in the long run. Well that is just another way to say 'battery'. If hydrogen is the 'right' solution for this is also highly questionable. Storing large amounts of hydrogen is not easy. Hydrogen fuel-cells and electrolysers are not very cheap and you need to scale vertically if you want to be able to consume high amounts of power in both directions. In addition, that whole stack makes it overall very inefficient. The only real benefit compared to a battery is that its easier to scale hydrogen tank then battery materials. However, there are other potential solution. A 'liquid air' battery, meaning liquidity air and on demand drive turbine, has better energy efficiency is more proven technology at large scale and has the same advantage of making bigger tanks result in larger storage. Flow batteries potentially can do the same thing as well. All that said, it seems to me that LFP (Iron Phosphate) based batteries will beat all of them once the production is fully going. LFP has very low material cost, and has a very long life and is very safe. One of the issues with chemical storage from 'leftover' renewable is that your energy consumers will have very low utility and your plant will run at very low overall utilisation. This is less of a problem with a LFP based chemical battery.

PhantomGremlin 6y ago

solar panels in the Sahara Given the inefficiency of photovoltaic -> hydrogen -> liquid hydrogen? transport (how, not easy) It would probably be easier to create and ship LNG. At least we know how to do that. But you're much better off just putting 2x or 3x the number of solar panels in countries that don't have as high a solar irradiance as the Sahara does. Or even do HVDC from the Sahara to Europe. That is probably much higher efficiency than trying to use hydrogen or natural gas. BTW in case anyone is interested, here is a map of solar irradiance: https://en.wikipedia.org/wiki/Solar_irradiance https://en.wikipedia.org/wiki/Solar_irradiance

glogla 6y ago
It would work with Antimatter though! Even better to make it on Mercury than on Sahara.
- TeMPOraL 6y ago
  On top of antimatter generation, we can also collect it in space, as it gets trapped in planetary magnetosphere. Antimatter harvesting works best in places with strong magnetic fields, which makes Jupiter and Saturn much better candidates ([0] claims Saturn is the best). Not sure how much we could capture in terms of mass/energy; the impression I get is that it may be worthwhile for space missions, but I'm not sure if it's enough to power a civilization. -- [0] - https://www.centauri-dreams.org/2016/08/03/antimatter-production-harvesting-in-space/ https://www.centauri-dreams.org/2016/08/03/antimatter-produc...

pjc50 6y ago

The standard answer for home heating is electrical-driven heat pumps.

dzhiurgis 6y ago
He makes a good point - fuel cell extra heat can go into house. Especially useful in places with no grid electricity.
davewritescode 6y ago
The problem is that solution doesn't scale to places where it's very cold. One reason electrical demand spiked in Texas was the fuel pumps stop working as efficiently as temperatures drop below freezing and most fuel pumps have coil backups which demand an order of magnitude more energy.
- burmanm 6y ago
  Well, heat pumps extracting from air would function until -35C (at least some models), but obviously the efficiency goes down a bit. But most do a fine job until -20/-25C. For even colder climates, one can use ground source heat pumps. So this should not be a problem for heating purposes. Cheaper cooling designed heat pumps do not obviously function to so low temperatures, but all Nordic models for example will function just fine.
  - tzs 6y ago
    To put some specific numbers on it, Mitsubishi's "Hyper-Heating" heat pumps claim 100% capacity down to 23℉ (-5℃), and 76% capacity down to -13℉ (-25℃). This is for their ductless mini-split systems. Fujitsu is similar. Mr Cool makes the claim [1] that theirs "can heat at 100% capacity at –5 degrees Fahrenheit, even with outdoor temperatures as low as -22 degrees Fahrenheit". I think Mr Cool is talking about a central system, and so they are claiming 100% with the outdoor unit at -22℉ (-30℃) and the indoor unit, presumably in your unheated crawlspace, is at -5℉ (-21℃). Mr Cool also claims cooling with an outdoor temperature up to 115℉ (46℃), which so far is under the max for much of Texas, so heat pumps are a good choice still in Texas as long as you get one of the newer models with the good low temperature performance. [1] https://mrcool.com/blog/introducing-mrcool-universal/ https://mrcool.com/blog/introducing-mrcool-universal/

nickik 6y ago

> And there's the potential for buffering excess renewable energy. for now this problem can largely be solved by improving the electricity transmission infrastructure between countries, but it's unclear to me that this is sufficient in the long run. Well that is just another way to say 'battery'. If hydrogen is the 'right' solution for this is also highly questionable. Storing large amounts of hydrogen is not easy. Hydrogen fuel-cells and electrolysers are not very cheap and you need to scale vertically if you want to be able to consume high amounts of power in both directions. In addition, that whole stack makes it overall very inefficient. The only real benefit compared to a battery is that its easier to scale hydrogen tank then battery materials. However, there are other potential solution. A 'liquid air' battery, meaning liquidity air and on demand drive turbine, has better energy efficiency is more proven technology at large scale and has the same advantage of making bigger tanks result in larger storage. Flow batteries potentially can do the same thing as well. All that said, it seems to me that LFP (Iron Phosphate) based batteries will beat all of them once the production is fully going. LFP has very low material cost, and has a very long life and is very safe. One of the issues with chemical storage from 'leftover' renewable is that your energy consumers will have very low utility and your plant will run at very low overall utilisation. This is less of a problem with a LFP based chemical battery.