July 1977 RAIN Page 17 Rocky Flats, aim at reducing the cost and increasing the reliability of 1,8 and 40 kw WECS. The cost goals.are $1500/ kw (without tower and batteries), $75O/kw (with tower) and $5o0/kw (including tower), respectively, for each of the three rated sizes.13 lf these lower costs are achieved, and most small systems designers and government researchers believe they will be, then the cost of energy from small units, as estimated for ERDA by I-ockheed, should drop further as shown by the dotted line and arrows in Figure 3.14 The Darrieus eggbeater or vertical axis wind turbine (VAWT), so appropriate for mounting atop and powering buildings in urban areas, is now sold by Dominion Aluminurn Fabricaling of Ontario, Canada, in 4, 6 and 2O0 kw sizes.15 DAF estimates that the $1175lkw first unit cost for its 200 kw system can be reduced to $500/kw with multiple orders.16 A 60 kw VAWT built by Sandia Laboratories in Albuquerque, New Mexico, also has the potential for converting wind power to electricity at a lower cost than that of the more common horizontal axis, propeller type machines discussed above.l7 We'll know how much less by early 1978. Since all the new wind generators that come out of these efforts are to be designed for mass production and are likely to be the most advanced, most reliable and most cost-effective small WECS in existence, those interested in residential and small business windpower would do well to either wait for their appearance in l97B-7 9 or make extremely good deals on commercial units now available. THE ENERGETICS OF WIND And now for the bad news. Prof. Howard T. Odum, famous for his use of net energy concepts to evaluate the energy flows in such living eco-systems as forests, marshes, streams and grasslands, has applied net energy analysis to windpower and found it to be the lowest relative to 12 other energy sources (see Table 1).18 TABLE 1-Evaluation of Net Energy of Some Primary Energy Sources. FIGURE 3-cost.t """;;;;;"ed by Small wind Generators, energJ/ to do work. 'l'be net en3rgy was often smttll or eaen negatiae. Windmills wlticb rtrn on relatiaely light winds and wbose manufacture inaolaes higb energy cnsts are not going to be mucb belp in tbe fttture. As costs ol' otber energies tbat uere nsed to subsidize uindmills in credse, tbe deficit in net energJ/ will increase Itfither, making tbe tecbnologically complic'ated windrnills less tttttl and less pract ical."zrJ One can only wonder rvhat wind would now be yielding in net energy relative to nuclear power if society's billions of dollars had supported the development of our benign Lrreezcs rather than the atom over the past 30 years. However, there are a few important omissions which reduce the accuracy and hence the usefulness of these nct cnerg)' analyses. Most importantly, as Amory Lovins has shown, it is necessary to ask the cost, whether in dollars of energy, of deliaered energy, especially as electricity as it is currently produced via centralized nuclear and coal is fraught with high transmission and distribution losses. Obviously a more dccentralized electrical generation scheme, using wind generators near the point-of-use, would have fcwer such losses. ln any case, analyses based on installed or sent out energy rre incomplete since people want, use and pay for energy they can use wbere tbey are. Secondly, there is no indication of thc windmill lifetime on which these calculations are based. It makes a difference whether the wind generator is considered to last only a few years, making the net energy very negativc, or whether it could last 50 years or enough time to produce positive net energy yields. As with life-cycle costing of buildings, we need to know the assumed lifespan in order to accurately calculate energy output over that lifespan. ln addition, Odum's calculations do not include thc governmentsubsidized costs of radioactive waste storage or the consumerFIGURE 4-Energy Flows Generating 1200 KWH of Elccdrtsruors nrurm. limoBralld. rtllArLAl0. sD sta cilotrlqt|o ccr txctuott lroiaot,urc4D orltRrstrm Uttt Tvpe Geothermal power (volcanic region)----------- Hydroelectric power- - - -- --- - - -- fidal power (20-ft tide)-------- Western coal and 1,000 mi tlansport---------- Alaska oil--------- Gulf of Mexico oil - - Near East orl by exchange, 1975--------------- Oil iil exchange lor grain, 1975---- - Nuclear lission power------ - --- --- Low enerSy agricultul€ 3- - ----- Low energy forestry- - :- -----:- Nuclear lission with an accident---- wind powered electnclty (10 mi/h)-. -. - - - - - - - - - I No Bel. I Yield ratio greater than l. Wind is not a primary s0urce' , iieia orui,te? by ieedback, both in equilv;lent enerSy unils of same quality (coal equivalents)' EnerSy costs of dGtributing enerSy to 0onsumers ar.a not lncluded' I Hiitr enerey agflcultulels not riet yiolding. Low energy agriculturo is' ,Yield ratiol 57.4 t9 13. 7 10. 6 b.J 6. 5.7 4.4 2.7 2.1 t.5 1.4 . .28 lhat is, relative to the amount of work provided by society as the labor, goods and services used to construct WECS (see F'ig. 4 )19 wind energy doesn't even yield as energy output what it requires as input cnergy . . ' not even 1-to-1 or breakeven! Odum sums it up this way, "Early windmills were made of'bulky uood, but later windmills were made of steel and rttber expensiae, bigbquality irtputs. As long as sr,tlar iiergy prouided the wood, ir cbiap fossil Juet was tbe primary source ol energt .for steel in electric windmills, it was possible to use wind Wind, l0 miles
RkJQdWJsaXNoZXIy NTc4NTAz