Arctic heat pumps and closed loop geothermal should be the only heat pumps sold in the state of Michigan.
In Marquette the average temperature is 20° in Dec; 15° in Jan; and 17 °in Feb. Nov & April in the 30s and March the mid-20s. Standard heat pumps end up using their back up electrical elements at these temperatures. Using as much energy as a furnace.
In Detroit Dec, Jan, and Feb average temps are still below freezing, March, April and Nov would offer a COP of about 2 (50% less energy).
With an Arctic unit, In Marquette the COP is above 2 (except for very cold nights) and reach 3 (67% savings) when the temperature was over freezing. In Detroit, COP would remain above 2.5 (with exceptions).
With a closed loop geothermal system that is designed for cold weather, the COP in both cities would remain above 3, again with exceptions.
In the summer the newest heat pumps have a COP of 4 or better for A/C.
In December in Marquette solar produces 4 percent of its annual output (45 of 1228 KWH) [NREL] and in Detroit December is about 4.5% of annual use.
By contrast in Dec residential load is almost 9% of electricity, and 15% of natural gas annual use.
Winter should be our concern when planning for the future.
How do we fix this mismatch?
Doug Houseman
Expert Member
Top Contributor