Yes at the meter, in the periods where the off-peak price is below the breakeven electricity rate for your furnace and heat-pump ratings — and only for the kWh that actually fall in those periods. This is the applied version of the time-of-use page. Using the same U.S. average sketch as that page, a 95% AFUE furnace at about 15.59/MMBtu is matched by an 8.1 HSPF2 heat pump at about 12.6¢/kWh. An off-peak rate of, say, 8¢/kWh would favor the heat pump at these ratings; an on-peak rate of 30¢/kWh would favor the furnace. Your gas price and HSPF2 change the threshold, which is why the calculator should be run with a custom rate, not only with the EIA average.
The catch is timing. A heat pump has to heat when the house loses heat. Preheating during a cheap window, a well-insulated shell, or a storage-heavy rate design can shift some kWh. A 7 a.m. or 5 p.m. pickup in January may still land on-peak. Do not assume that “we have off-peak rates” means every heating kWh is billed at the night price.
Run the calculator twice — off-peak and on-peak — as bookends, or build a usage-weighted cents-per-kWh if you have interval data. Dual fuel can take the expensive hours on purpose: heat pump off-peak, furnace when the rate or the COP is against you. HSPF2 remains a seasonal Region IV rating, not a TOU-weighted COP.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.