I found this chart interesting. It is the On Peak Weekly Average (Day Ahead) for SE Mass in the NE ISO from 2004-2007. It does need to be indexed to natural gas prices in NE but look at 2006, 2007. The exponents of the power law equations of all the years (except 2005) are fairly close. 2005 had Katrina which really spiked the prices at the end of the year. I expect that when I index the prices to nat gas, the chart will be even more behaved. You can also see that the highest and lowest weeks don't quite fit. They could be partitioned out to make the fit better. Also, there could be different ways to analyze this data.
