At 5:31 PM 2/15/5, Jed Rothwell wrote: >>Though this is all good discussion and the approach may yield practical >>results for a while, it is important to realize that wind can not solve all >>the worlds energy problems, and working on a new *source* of energy is the >>big problem. > >I'll bet wind could supply half the world's energy, especially in countries >far from the equator. It could easily supply all energy in the U.S. and >Northern Europe, and most in northern China.
Well, you do have a point there, provided energy were generated in a storable and transportable fashion. The DOE page: <http://wwweia.doe.gov/oiaf/ieo/world.html> shows the world energy consumption at about 400 quadrillion Btus. That's 400x10^15 Btu or 1.172x10^14 kWh. Given 365 days/yr and 24 h/day that requires a continuous generating capacity of 1.338x10^10 kW = 1.338x10^7 MW = 1.338x10^4 GW. Assuming a minumum of 50 percent loss for transportation and storage, that would be about 27 thousand GW sized windmills (if that's feasible), or 27 million MW windmills. A number more like 6 million 5 MW windmills is closer to what is presently workable, and in reality there would be a wide range of capacities. Gee if they could be made for $1M a piece, that's only $6T. Not bad amortized over 20 years. To be workable worldwide the ouput would not be mostly electrical though, but probably hydrogen. Liquified air might have a place in this scheme as well. I posted in "The Legacy Plan" various times here: "Though the planning horizon for hydrogen is long, it still may be useful to give special weight to projects which produce hydrogen, and to support hydrogen storage, generation, transportation, and fuel cell research. Similar consideration may be warranted for methods of methane production from atmospheric carbon using renewable sources. If wind energy costs continue to decline as in the past 20 years, hydrogen or methane producing wind farms should be cost beneficial within 10 years. This makes feasible many additional locations for major wind energy generation, like Alaska. With sufficient research and appropriate legislation, Alaska alone has the potential to provide the US energy growth needs for generations, though it may take a commitment similar to that of going to the moon to realize it." Alaska mountain tops have formidable wind roses. If the wind there can be harnessed at the -40 F and lower temperatures which often occur there, at at the huge wind velocites, air liquifaction could be fairly efficient, and carbon removal from the atmosphere to make methane from electrolysed hydrogen may also be feasible. The principle problem is energy transportation and storage. Methane is easily transported and stored, even internationally, and there may even be a gas pipeline to the US soon. The principle value of a liquified air approach is that it is doable without major research. It is achievable using engineering alone. That has some merit. The down side is there is a theoretical limit to efficiency and if cheap hydrogen storage technology appears it could obsolete the investment. On the other hand, the investment in the windmills themselves would not be obsoleted, so there may be a timely niche there. It would be interesting to look at the economics of a liquified air shipping model, where the product is bulk stored and then converted to electricity at an equatorial destination. Bulk cryogenic storage is much more efficient than small storage. Also of interest is hydrogen generation and piping to electrical generation plants, vs HV DC power generation and conversion, which could become a very good land transport alternative if room temperature superconductors appear. Regards, Horace Heffner
