The release goes on to say they expect commercialization and deployment in 2024.
I think a COP of 2 at 5°F (-15°C) is pretty good.
My new car can do 100% driving!
Surely not engineering way of thinking but that's a common heat pump metric for ordinary people.
"Coefficient of performance" is a better term.
If someone asks: "how efficient is this heat pump at heating my house?" And you start digressing about how that's the wrong question to ask you'll be giving them an impression opposite reality, which is for most people: it will use less electric energy than heat energy it puts into your house, almost all the time.
So the ">100%" comes from the fact that you're spending less thermal energy than you are moving?
Even electric heat alone is 100% efficient no incomplete combustion or degradation over time. Efficient bu much more expensive than just moving heat already in the air.
Ground-source are better for now since they are moving heat from a relatively consistent source the Earth. It's about 15C to 25C one meter down where the ground-source heat pump lines are run.
Generating vs moving heat I think is misunderstood by people or really more likely they just don't care. As long as the bill is low!
Running a steam turbine by pushing water down a borehole to come into contact with a high-temp (>100°C) source has been done; it's not perpetual motion. Energy pumping the water is << energy output from the steam produced. It's solar energy that's being used, ultimately.
The 300% efficiency means if you had 1 Watt you could use it to power a fan and coolant lines to move heat. Or use 1 Watt to generate heat and then once made to move that heat.
The moving of heat already existing in the air (or in the ground) is more efficient than generating the heat and then moving it.