The operative wind speed ranges for a typical wind project, begin at speeds of about 9 mph and reach the project’s rated capacity at 33-34 mph. Within that range, any power depends upon the cube of the wind speed, thereby accentuating the project’s fluctuating volatility. It’s one thing to consider the requirements for compensatory generation when the wind isn’t blowing in the necessary speed range; and it’s another to understand the dynamics involved even when the wind is blowing within that speed range. When, for example, a wind project with a rated capacity of 1000MW is only producing 50MW–or nothing–at peak demand times, conventional generators must fill this breach. At the same time, when that same wind project is producing 600MW in one minute, 500MW the next, 550 the next, 450 the next, and so on, instant compensation from conventional generators is required. Given the conditions imposed by the cube of the wind speed, this is business as usual for wind energy. Finally, however, at times the wind energy will ebb and spike precipitously, causing wind and rapid changes that also must be compensated for by large scale dynamics–typically inefficient thermodynamics.

Wind volatility increases and intensifies the mechanisms used to balance demand fluctuations, which by themselves impose significant financial costs. Adding wind flux can only increase those costs, not decrease them. I suspect that these increased costs are not simply arithmetic but rather exponential: as more wind penetrates the system, the costs of wind integration cascade. An independent energy economist might discover a fruitful yield from this kind of inquiry.

All the ways in which wind flux can be compensated for by conventional thermal plants–natural gas, coal, oil– on a routine operational basis results in substantial CO2 costs. Kent Hawkins’ calculus supports Peter Lang’s conclusion that an efficient collaboration of open and closed cycle gas units working in tandem with wind energy, could result in CO2 system offsets that achieve about 15% greater yield than would be achieved by the gas units alone, without wind. Using only OCGT, both analyses suggest little or no savings. Using coal and oil as the primary means of wind integration would increase system CO2 emissions beyond the levels produced without the addition of wind.

Engineers, using many of the same techniques designed for balancing demand fluctuations, can integrate wind volatility at varying levels of penetration. If it’s only a few percentages of total supply, no additional conventional supply seems to be necessary. Beyond this, as the level of wind threatens marginal safety reserves, additional conventional supply must be considered for grid security. No matter what engineers do, however, they cannot escape increasing the financial costs rather substantially. And they cannot avoid increasing the thermodynamics. In most cases, they are faced with the prospect of actually producing more CO2 than would be generated without any wind at all.