The duck curve tells us prices are lower at noon due to tons of new solar, but what about the rate of price change?

Are electricity prices at noon climbing faster, or less fast, than prices at 6pm?

My rates off-peak have increased faster than the on-peak rates, presumably because the on-peak rates were already sky high.

In the last couple years peak has gone from ~0.36 to ~0.56, while off-peak went from ~0.12 to ~0.27.