The chart is from a conservative think tank in Minnesota funded by the Koch Foundation. They are major players in oil and gas exploration, refining and shipping

It looks like the price per KH is total price from all sources of generation. I would think the rise in the price on natural gas and oil is the factor that is causing the price increase in electric rates.

In Maine, it’s also the rise in natural gas prices that is causing the electricity prices to surge. Not solar.