Excess wind and solar power can be used to generate hydrogen from water.
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].
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?
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.
Also many places don't have reservoirs and mountains for pumped storage.
I'm not a big believer in the hydrogen economy, but at least incorrect notions should be corrected ("no source of hydrogen besides natural gas to be seen").
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.
...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.
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.
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.