I'm guessing based on what I happened to know of heat pumps in practice in sweden, but I think it makes sense to assume this. The reason is that the temperature

I'm guessing based on what I happened to know of heat pumps in practice in sweden, but I think it makes sense to assume this. The reason is that the temperature difference between sweden and Germany is probably less than 1%. Temperature in sweden averages about 2 degrees C, and the temperature in germany about 3 degrees C, which can look like a 50% increase, but everything in thermodynamics works in Kelvin, not C. So the difference is between 275 and 276 degrees K, which is about 0.3% or almost nothing. Its not enough to prove anything, just make it reasonably likely, which is then combined with the qualifier.