Unadjusted daily data. 10-day moving average.
20-day moving average.
30-day moving average. I received a number of comments on the post below, along with some accusations of "data mining" for showing only the raw data (see top chart above), and not showing adjusted, moving-average data. OK, OK, but please keep in mind that there are only so many hours in the day, and finding raw data and creating charts is pretty time-consuming, and I have many other obligations, so I didn't have time yesterday to make adjustments to the data.
Today I found the time, and the bottom three charts above show adjusted wholesale electricity data for the 10-day moving average (-61.3% decline from the July peak), the 20-day moving average (-57.1% decline from the peak) and the 30-day moving average (-51.1% from the peak). In all cases, the current wholesale electricity price of $47.38/MWh is close to a four-year low, and will likely continue to fall.
Bottom Line: Wholesale electricity prices, along with with oil, gasoline and natural gas prices, have fallen significantly since the summer 2008 peaks. Whether the decline in wholesale electricity is -50% or -77% seems less important than the fact that the decline is significant, and energy price declines for oil, gasoline, natural gas and electricity will create significant savings (billions of dollars) for consumers and businesses in the coming months.