Concerning your "Wind Capacity Blows Away Record" article (March 2008) I do not share your enthusiasm for this source of electricity for economy reasons. According to the article, a 5.2 GW (billion watts) nameplate capacity was installed for 9 G$ (billion dollars) in 2007. Considering that the actual production is only about a fifth of the nameplate (it is reduced with the so called capacity factor and for the field power fed into the generator from the outside) one ends up with 9 dollars for each watt of net output (9 G$ / 1 GW) - a disproportionate sum in comparison with, for example, the 1.5 $/W with nukes to cite an example of a non-CO2-generating source of electricity.
Wind proponents might argue that wind plants are about three times cheaper than, for example, the PV plants (30 $/W). True, but one might expect a breakthrough in that price. Not so with the wind turbines - they are performing too close to their theoretical efficiency limit already to produce appreciably more power per cost in the future. Cost reduction due to mass manufacturing is also unlikely considering that just about all wind mills worldwide are made in Denmark, mass produced. On a related subject, please let your reader notice that using SI units and prefixes makes comparisons among energy numbers immediate. They eliminate the need for conversions among the plethora of energy units (Btu, kWh, therms, joules, etc.) along with the not-so rare conversion mistakes. Values in SI let us compare all parameters be it a capital outlay such as $/W or $/m², costs such as in fuel or electricity (both in $/GJ), the amount of space taken in W/m², annual consumption/production in joules (EJ), annual average power in watts (GW), etc. Once everyone use SI, we'll be better positioned for cooperation in solving the energy crisis. As in all fields of engineering, by using SI we will soon remember energy and power reference values because the numbers will be unified and ubiquitous. Cross-disciplines communication becomes easier. The multi-meaning numbers "billion", "milliard" and similar words causing confusion today will become clear when replaced with the giga- or whatever appropriate, prefix. Stan Jakuba member of ASME 43 Westbrook Rd West Hartford CT 06107 Tel: 860 521 7924
