Have we really thought through the implications of Heat Pumps?
Steve Miller, PE
Owner of HVAC Design Solutions, HVAC and Plumbing software packages, eBooks, and apps for tablets.
Have we really thought through the implications of Heat Pumps?
If these recommendations are followed before the electrical grids and microgrids are converted to renewable energy, the greenhouse gases released into the atmosphere will be increased, not decreased! (Continuation - 2)
Regarding the effect that extensive additions of electric Heat Pumps will have on our power supply:
· An indicator that California recognizes the problems with existing power grids (7/4/2022):
“The energy trailer bill negotiated by Gov. Gavin Newsom's administration and approved by lawmakers late Wednesday allocates a reserve fund of up to $75 million to the state Department of Water Resources to prolong the operation of aging power plants scheduled to close. Diablo Canyon (nuclear power plant), on the coast near San Luis Obispo, has been preparing to shut down for more than five years.” The bill is intended to maintain the reliability of the state's increasingly strained power grid and avoid the damaging prospect of brownouts or blackouts.
· If all existing homes that do not currently have central air conditioners are now required or enticed to add Heat Pumps to replace existing gas furnaces, the additional load on the electrical systems will be extensive. It is highly unlikely that existing power grids, substations, and electric services would have been designed for every residence to have either central air conditioners or Heat Pumps. Also, during cold nights, the simultaneous use factor of all residences’ Heat Pumps/electric coils could approach 100%. During the summer, the newly added Heat Pump residences (who previously didn’t have central AC) will be significantly increasing the air conditioning load on the electrical systems.
Regarding Heat Pump efficiency versus cold outdoor temperatures:
· If a Heat Pump is installed with a 3.5 COP (350% efficiency) to provide 24,000 BTUH of heating at 45 degrees F outdoor temperature, it will only have an approximately 2.3 COP at 10 degrees F outdoor temperature and will only produce about 15,000 BTUH of heating. To produce the desired 24000 BTUH, either an electric coil is required (1.0 COP), or the Heat Pump will have to be oversized to accommodate the lower temperatures.
Directeur projets énergie chez EQUANS Services - North America
2 年Without denying the distribution and supply issues, there are several low cost measures that can be implemented to mitigate the impact. For exemple, load shedding (electric water heaters, charging EVs at night, pre-heating and letting the temperature drift slightly during the grid peak. This can be encouraged by credits on utility bills or dynamic tarifs. Obviously, that won't be enough so there will still be a need for storage (electric and thermal) and demande response. The idea is to reduce the emissions over the majority of the hours (heat-pumps are the best for this), end-users' involvement and topping up when needed.
President at B & L Mechanical, Inc.
2 年You’re correct! I met with our TRANE HVAC vendor today and TRANE is totally pushing heat pumps over gas/electric units and have actually lowered the heat pump prices over gas/electric in it’s! At least in California where our Governor is pushing for all electric cars, trucks and HVAC systems!!!