On Dec 13, the Midwest Wind Integration Study, (see article) which was required by the Minnesota legislature in 2005 to evaluate reliability and other impacts of higher levels of wind generation and carried out independently by EnerNex Corporation and WindLogics, found that the total integration cost for up to 25% wind energy delivered to all Minnesota customers is less than one-half cent ($0.0045 cents) per kWh of wind generation. Great news, but it’s a little bit anticlimactic (as well as “anti-climatic change”) compared to the announcement on Dec 5 that Denmark plans to increase wind powerfrom 20% today to over 50% by 2025. (All penetration rates are given as percentage of power supplied, as opposed to nameplate capacity, a measure which would make wind penetration rates seem even higher.)
That’s not to say this report is a total yawn. First, Europe has a much more robust electric grid than the US (as the Northeast found out in 2003), and the fact that the study was sanctioned by a government body, rather than a renewable energy or environmental group gives it added weight. Finally, by using extensive simulation, they came up with some relatively hard numbers on what it would cost to reach various levels of penetration.
The study concludes that the total integration operating cost for up to 25%wind energy delivered to Minnesota customers is less than $4.50 per MWh of wind generation, or less than 1/2 of 1 cent per kWh. Put another way, this is less than 10% of the average cost per kWh of wind energy.
As I alluded to before, when talking about Europe, we need to be careful when we generalize from one utility grid to another as to the costs of integration: Europe’s grid is not the same as America’s, and Colorado’s grid is not the same as Minnesota’s. Costs for integrating wind into Colorado’s grid are likely to be higher than in Minnesota, because we are behind the rest of the country in terms of how robust and well integrated our grid is to the rest of the country. Because of the limitations of out grid, all of the major wind farms now in Colorado or under construction have had to be scaled back.
Nevertheless, the study is great ground for hope. Colorado desperately needs to upgrade our transmission anyway, and the Minnesota study only takes advantage of one of the many possibile strategies that helps firm up the capacity factor of wind: geographical diversification: “the wind is always blowing somewhere.”
Other strategies not considered:
- Time of use pricing, which can be used to shift demand to times when the wind is blowing.
- Plug in Hybrids, which can be programmed to be charged when power is cheap, or even supply peaking capacity to the grid.
- Energy storage, such as the Wind-to-Hydrogen project recently unveiled at NREL’s Wind Technology Center (in partnership with Xcel Energy.) One interesting aspect of this project that did not make most of the articles on the center is that they are experimenting with directly connecting the wind turbine to the electrolyzer, without the intermediate step of a transformer which has to be used to convert the wild AC power from a wind turbine the regulated AC power used by the grid.
In short, I see 25% as a good start, but given that wind power has already shown itself to be cheap, safe for the environment (despite claims to the contrary, wind kills far fewer birds than coal; just ask the Audobon society), and is proving much easier to integrate into the grid than skeptics imagine, we need to start thinking like Denmark, and aim for numbers much higher than 25%. It will take creative thinking, and serious investment not only in wind farms, but also in our grid, and even behavioral changes on the part of consumers.
The small sacrifices we will need to make in terms of our behavior to get large penetrations of wind onto the grid, such as checking our time of use meter before we start the dishwasher or dryer, are much smaller, in my mind, than the giant sacrifices we are currently making to coal fired generation in terms of the effects of pollution and global warming on ourselves and our children. We just don’t see the current sacrifices, because we have become used to the death from a thousand cuts in the form of mercury and other pollutants, and the incremental year on year warming of our planet, lost in the noise of large local and seasonal variations.
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