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Excess wind and solar power can be used to generate hydrogen from water.

soperj 12y ago
and Hydro as well.
crimsonalucard 12y ago
There is no excess. Renewables do not have anywhere near the capacity to charge a fuel cell automobile economy. Additionally, if there was capacity why not use it to charge lithium batteries?
- rhino369 12y ago
  >Additionally, if there was capacity why not use it to charge lithium batteries? Cost, weight, and refueling/recharge. Lithium batteries are expensive, heavy, and have a limited lifespan. I think batteries will win out, but it is not a certainty. Toyota seems to think Fuel cells will win.
- D_Alex 12y ago
  >There is no excess ...yet. But solar and wind power are becoming the cheapest way to generate electricity. Their naturally variable production will mean that there will be periods of excess power available, and finding a good use for that excess would be nice. But I agree that batteries, not hydrogen, are the way to go.
  - crimsonalucard 12y ago
    When you factor in all the sources of energy consumed in this country, captured solar power amounts to well less than 1 quadrillion Btu out of an annual total of 96.5 quadrillion. There will never be an excess of solar or wind. Even if you continue the dramatic growth in renewables of the past decade there is utterly no chance that renewables can replace fossil fuels. The gap is too great. You are living in a dreamworld if you think that the path to a sustainable future can be found through technology alone. Sustainability can only be achieved by dramatically lowering our energy consumption rate.
    - D_Alex 12y ago
      >There will never be an excess of solar or wind. Even if you continue the dramatic growth in renewables of the past decade there is utterly no chance that renewables can replace fossil fuels. The gap is too great. 1. Wind and solar energy is currently about 3% of the world's supply, and projected to grow at 6-8% per annum (source: BP Energy Outlook 2015, and others), meaning it doubles every 10 years or so... wind and solar may well become the dominant energy in our lifetimes. 2. There already is an excess of wind power, in some places at some times. Where I live (Perth, Australia) wholesale energy prices go negative several times per month, typically at night when the wind is blowing and power demand is low. > You are living in a dreamworld if you think that the path to a sustainable future can be found through technology alone. Sustainability can only be achieved by dramatically lowering our energy consumption rate. I disagree completely - lets see what happens say over the next ten years.
graphene 12y ago
Unfortunately, there's no efficient process for that. Efficiency of electrolysis (when not using expensive catalysts) is around 50%.
- ars 12y ago
  Use thermolysis instead. You can power it with waste heat from a nuclear plant.
- gambiting 12y ago
  And that's not even half of the process. Electrolysis produces gaseous hydrogen, it needs to be cooled down to store as a liquid, which requires a LOT of energy as well.
- sliverstorm 12y ago
  We know that hydrogen has obstacles when it comes to efficiency... but we also know that batteries have obstacles when it comes to chemical environmental friendliness (primarily manufacture and disposal). Has anyone done a comparison of that aspect of environmental impact?
- Symmetry 12y ago
  I seem to recall that synthesizing methane or hydrocarbons from water and atmospheric CO2 isn't that much less efficient than that. Given the efficiency of internal combustion engines versus fuel cells and existing infrastructure you might as well get your carbon neutral transportation that way instead of with hydrogen.
sandstrom 12y ago
I think that with current technology it's more efficient to store that energy in a battery than in the form of hydrogen (hydrogen is just a storage mechanism). But it's a storage mechanism with the huge downside of being available from natural gas, so with widespread use of hydrogen we be equivalent to widespread continuous pumping of huge amounts of CO2 into oceans and the atmosphere. Something which most people consider foolish[1]. [1] http://en.wikipedia.org/wiki/Effects_of_global_warming http://en.wikipedia.org/wiki/Effects_of_global_warming
- rational-future 12y ago
  Most people you know maybe. Most people I know are quite foolish themselves and repeat whatever their favorite TV station has brainwashed them to believe about the global warming.
- Gravityloss 12y ago
  Of course it's more efficient to use batteries, these are all entry level arguments. Perhaps I misread the audience. The infrastructure cost is totally different. Electrolysis and immobile storage of hydrogen is very cheap. We don't have a lot of places where for a significant portion of time when there is excess power from renewables, but we will, in the future. Edit: To clarify: if you want to produce say 40% of your yearly energy needs from wind and solar, you have to oversize the production since there are many days they produce very little. That then means there are days when they produce more than is consumed. The excess energy could be used for electrolyzing hydrogen from water. Note no carbon involved. Also the low efficiency doesn't matter, as the energy is "free". Low cost of energy storage method is much more important in this case. Any other reasons than "batteries are more efficient" for downvoting?
  - dTal 12y ago
    >immobile storage of hydrogen is very cheap Where did you get this idea? You have to keep liquid hydrogen extremely chilled, under extreme pressure, and it inevitably leaks out. Compare to pumped water energy storage, which is at ambient temperature and pressure and has similar efficiency to the electrolysis -> fuel-cell cycle.
deleted 12y ago
[deleted]
ThrustVectoring 12y ago
At that point, you may as well use the power to build hydrocarbon chains out of CO2 and H2O. And as a bonus, we already have the infrastructure for using hydrocarbons as vehicle fuel.

and Hydro as well.

There is no excess. Renewables do not have anywhere near the capacity to charge a fuel cell automobile economy. Additionally, if there was capacity why not use it to charge lithium batteries?

rhino369 12y ago
>Additionally, if there was capacity why not use it to charge lithium batteries? Cost, weight, and refueling/recharge. Lithium batteries are expensive, heavy, and have a limited lifespan. I think batteries will win out, but it is not a certainty. Toyota seems to think Fuel cells will win.
D_Alex 12y ago
>There is no excess ...yet. But solar and wind power are becoming the cheapest way to generate electricity. Their naturally variable production will mean that there will be periods of excess power available, and finding a good use for that excess would be nice. But I agree that batteries, not hydrogen, are the way to go.
- crimsonalucard 12y ago
  When you factor in all the sources of energy consumed in this country, captured solar power amounts to well less than 1 quadrillion Btu out of an annual total of 96.5 quadrillion. There will never be an excess of solar or wind. Even if you continue the dramatic growth in renewables of the past decade there is utterly no chance that renewables can replace fossil fuels. The gap is too great. You are living in a dreamworld if you think that the path to a sustainable future can be found through technology alone. Sustainability can only be achieved by dramatically lowering our energy consumption rate.
  - D_Alex 12y ago
    >There will never be an excess of solar or wind. Even if you continue the dramatic growth in renewables of the past decade there is utterly no chance that renewables can replace fossil fuels. The gap is too great. 1. Wind and solar energy is currently about 3% of the world's supply, and projected to grow at 6-8% per annum (source: BP Energy Outlook 2015, and others), meaning it doubles every 10 years or so... wind and solar may well become the dominant energy in our lifetimes. 2. There already is an excess of wind power, in some places at some times. Where I live (Perth, Australia) wholesale energy prices go negative several times per month, typically at night when the wind is blowing and power demand is low. > You are living in a dreamworld if you think that the path to a sustainable future can be found through technology alone. Sustainability can only be achieved by dramatically lowering our energy consumption rate. I disagree completely - lets see what happens say over the next ten years.

graphene 12y ago

Unfortunately, there's no efficient process for that. Efficiency of electrolysis (when not using expensive catalysts) is around 50%.

ars 12y ago
Use thermolysis instead. You can power it with waste heat from a nuclear plant.
gambiting 12y ago
And that's not even half of the process. Electrolysis produces gaseous hydrogen, it needs to be cooled down to store as a liquid, which requires a LOT of energy as well.
sliverstorm 12y ago
We know that hydrogen has obstacles when it comes to efficiency... but we also know that batteries have obstacles when it comes to chemical environmental friendliness (primarily manufacture and disposal). Has anyone done a comparison of that aspect of environmental impact?
Symmetry 12y ago
I seem to recall that synthesizing methane or hydrocarbons from water and atmospheric CO2 isn't that much less efficient than that. Given the efficiency of internal combustion engines versus fuel cells and existing infrastructure you might as well get your carbon neutral transportation that way instead of with hydrogen.

sandstrom 12y ago

I think that with current technology it's more efficient to store that energy in a battery than in the form of hydrogen (hydrogen is just a storage mechanism). But it's a storage mechanism with the huge downside of being available from natural gas, so with widespread use of hydrogen we be equivalent to widespread continuous pumping of huge amounts of CO2 into oceans and the atmosphere. Something which most people consider foolish[1]. [1] http://en.wikipedia.org/wiki/Effects_of_global_warming http://en.wikipedia.org/wiki/Effects_of_global_warming

rational-future 12y ago
Most people you know maybe. Most people I know are quite foolish themselves and repeat whatever their favorite TV station has brainwashed them to believe about the global warming.
Gravityloss 12y ago
Of course it's more efficient to use batteries, these are all entry level arguments. Perhaps I misread the audience. The infrastructure cost is totally different. Electrolysis and immobile storage of hydrogen is very cheap. We don't have a lot of places where for a significant portion of time when there is excess power from renewables, but we will, in the future. Edit: To clarify: if you want to produce say 40% of your yearly energy needs from wind and solar, you have to oversize the production since there are many days they produce very little. That then means there are days when they produce more than is consumed. The excess energy could be used for electrolyzing hydrogen from water. Note no carbon involved. Also the low efficiency doesn't matter, as the energy is "free". Low cost of energy storage method is much more important in this case. Any other reasons than "batteries are more efficient" for downvoting?
- dTal 12y ago
  >immobile storage of hydrogen is very cheap Where did you get this idea? You have to keep liquid hydrogen extremely chilled, under extreme pressure, and it inevitably leaks out. Compare to pumped water energy storage, which is at ambient temperature and pressure and has similar efficiency to the electrolysis -> fuel-cell cycle.

deleted 12y ago

[deleted]

ThrustVectoring 12y ago

At that point, you may as well use the power to build hydrocarbon chains out of CO2 and H2O. And as a bonus, we already have the infrastructure for using hydrocarbons as vehicle fuel.