1. The author relies on a fictional thought experiment that is completely divorced from the reality of how the power system actually operates. He asks us to imagine a power system “with no electricity imports or exports across state borders. Assume a constant load with no daily or seasonal variation.” Unfortunately for Mr. Pavlak, that is the exact opposite of how our power system actually works. Electricity demand is constantly fluctuating, varying by a factor of two or more depending on the time of day and year as factories, air conditioners, and other electric appliances ramp up and down. Relatively small changes in the weather can have major impacts on electricity demand for air conditioners and electric heaters. Electricity supply from conventional power plants is also highly variable and uncertain as large fossil and nuclear power plants experience unexpected outages on a regular basis, requiring grid operators to keep 1000+ MW (enough for a large city) of expensive fast-acting backup generation online at all times. In contrast, changes in wind energy output occur slowly and are generally predictable, allowing grid operators to accommodate that variability at a far lower cost.
The variability of wind energy is even more greatly reduced when the output of wind farm plants spread across a large geographic region is aggregated. Maryland’s electric system is combined with those of 13 other states, which means that changes in wind turbines output in Maryland are typically canceled out by opposite changes in wind output occurring as far away as Illinois. When aggregated over such a large area, the variability in wind turbines output is a small fraction of the variability exhibited by electricity demand, and Maryland can increase its wind output dozens of times over and that will still be the case. Thus, Mr. Pavlak’s thought experiment of an isolated power system with no variability in electric demand fails on both counts.
2. Next, Mr. Pavlak tries to argue that a power system that obtains 25% of its electricity from wind farm and 75% from natural gas is not clean. PJM and Maryland currently obtain about half of their electricity from coal, which emits significantly more pollution than natural gas, so such a power system would be far cleaner than what exists today. In addition, grid operator studies and real-world experience in Europe have shown that even with today’s technology and power system, wind turbines can reliably provide 50% or more of the electricity on a power system. Improvements in how we operate our power grid and the introduction of new technologies like demand response and plug-in hybrid electric vehicles will push that share even higher.
3. Finally, Mr. Pavlak’s arguments about the cost of wind energy are incorrect. A report issued by the U.S. Department of Energy last week documented that wind energy costs have fallen drastically over the last several years, to the point that wind energy at the best wind farm sites now costs a small fraction of the cost claimed by Mr. Pavlak. In addition, the figures cited by Mr. Pavlak take away the sole government incentive for wind energy but not the multiple large subsidies for fossil fuels and nuclear, so they are hardly a balanced picture of the actual costs of different technologies. As other commenters have noted, the costs for other energy technologies would increase even more if one factored in the massive environmental, public health, and other costs associated with their use.
By Michael Goggin, American Wind Energy Association Manager-Transmission Policy, www.awea.org/blog/