In the "generic" wind power schemes one commonly reads about, the maximum demand that wind turbines can satisfy, in a given grid segment, hovers around 30%. This limition exists because wind's variability has to be buffered with traditional "base load" generators. The upshot is obvious: up to 70% of grid power must come from a combination of hydro, fossil fired, or nuclear generators. Including hydro in the renewable catgory gets us to about 50%. In that more favorable mix, a kilo of H2 is still only half-helpful for climate change mitigation. Not a good outlook it would seem, given the accelerating demand growth for grid-distributed electricity and the creeping pace of adding renewable sources. That's the downside view as epitomized by James Kunstler's recent work, also covered here on TreeHugger.
Make hydrogen mainly at point of consumption and its going to be dragging a big fossil fuel burden along -- the half-clean, half-dirty hydrogen dilemma. Make hydrogen where wind power density is highest, but at distance from where it will mainly be consumed, and there's a chance to reduce the carbon and nuclear sources. Or...at least keep the carbon intensity down to what's needed to construct processes, operate some of the equipment, and distribute the hydrogen.
There's a second reason why wind power potential is highly constrained in the "generic" view: the best places for wind power have poor or no grid interconnections to where electricity and transportation fuel demand is growing. Building the new lines to make those connections to population centers will be a major NIMBY and cost issue; and, the line losses will still hover around 6 to 9 percent. Better, then, to skip over the interconnection problem and make the hydrogen where wind power is optimum, and the chance of land use conflict minimum, trading those off for the need to move the hydrogen to customers.
Now back up a bit and think what happens if commercial scale wind farms on the high plains pool their output into electrolyzer banks, where hydrogen is synthesized directly, then put in transportation ready containers destined for a hub and spoke distribution network.
Let your imagination into the no-Kunstler zone for this part. The trucks that haul the hydrogen away from these windfarms consume hydrogen as a fuel. On the outbound side, trucks drop off their full H2 cannisters at regional ports where they are transferred to trains and barges destined for distant population centers and highway corridors. Distant means the coasts, plus the Great Lakes and major river cities like St. Louis: all areas that developed originally because of access to water transportation. On the return side,barges back-haul empties to inland transfer ports, trucks pick up empty hydrogen containers, and, if needed to top the load off, some purified water and consumer goods, all back-hauled to the plains of the buffalo, where more hydrogen is being made.
This scheme increases the economic viability of interstate railroads and waterways. Prairie states become more sustainable and stop losing population to the "coasts". Given our electoral system and the tradition of Federal infrastructure support in the West, it's at least in the realm of possiblity. Keep that 'independent spirit' thing alive.
Look at the wind power density charts and you'll see that many of the the very best places are midway between the coasts, straddle transcontinental rail lines, and have spur or direct access to barge services.
In the Drive-By-Wind scenario, then, the power grid load/supply balancing and interconnection issues disappear at the regional and national levels.
Electrolyzers are easily scaled between very small to very large. At the local level, TreeHuggers can bundle one with a backyard wind turbine to make hydrogen for fuel cell powered farm machines or pickups. The potential of running the hydrogen back into a CHP fuel cell means any excess hydrogen can be used to generate electricity and domestic heat when there is a lull in the wind. This is the so-called "hydrogen battery". Prototypes are being tested in single wind turbine/fuel cell set ups.
Back to the regional view, electrolyzers can be assembled in large banks for commercial scale "on-farm" H2 production. Functioning prototypes of these exist as well.
Its predetermined that there will be intense political resistance to the commercial scenario outlined above, driven by many vested interests. Under such attacks, what other forces might move the "Drive-by-Wind" scenario forward? There would have to be a collaboration, possibly led by a large business with a strong vision of opportunity in sustainable development.
This scenario needs many more elements thoughtfully folded in to pass a broader plausibility test. Still, doesn't it just send a small shiver down your spine?