Analyzing the Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity at Different Sites in California and the Northwest

Wind power production varies on a diurnal and seasonal basis. In this report, we use wind speed data modeled by TrueWind Solutions, LLC (now AWS Truewind) to assess the effects of wind timing on the value of electric power from potential wind farm locations in California and the Northwest. (Data from this dataset are referred to as "TrueWind data" throughout this report.) The intra-annual wind speed variations reported in the TrueWind datasets have not previously been used in published work, however, so we also compare them to a collection of anemometer wind speed measurements and to a limited set of actual wind farm production data. The research reported in this paper seeks to answer three specific questions:

1. How large of an effect can the temporal variation of wind power have on the value of wind in different wind resource areas?
2. Which locations are affected most positively or negatively by the seasonal and diurnal timing of wind speeds?
3. How compatible are wind resources in the Northwest and California with wholesale power prices and loads in either region?

The latter question is motivated by the fact that wind power projects in the Northwest could sell their output into California (and vice versa), and that California has an aggressive renewable energy policy that may ultimately yield such imports. Based on our research, we reach three key conclusions.

• Temporal patterns have a moderate impact on the wholesale market value of wind power and a larger impact on the capacity factor during peak hours.
• Northwestern markets appear to be well served by Northwestern wind and poorly served by California wind; results are less clear for California markets.
• TrueWind and anemometer data agree about wind speeds in most times and places, but disagree about California's summer afternoon wind speeds.