@brtietz I'm finally getting around to documenting these changes for Help.

The default PVWatts/Commercial case has TOU demand rates with 2 TOU periods each and 2 tiers, so I was expecting to see 4 values per month in the hourly "Demand charge with system" output. But instead, I'm seeing a handful of "Demand charge with system" in $ values per month that do not always correspond to the "Electricity peak from grid" in kW, and I'm seeing negative values in the first day of the month even without billing demand ratchets. Can you help explain what these values represent?

Originally posted by @cpaulgilman in #652 (comment)