‘Sustainable’ in the food context is much more around total resource use (land, water, materials), waste products (ghgs and waste water) rather than a primary focus of energy efficiency.
Besides - heatpumps are largely the exception in thermodynamics, expecting anything more than 100% efficiency for most non-heat moving applications should not be expected.
Besides - heatpumps are largely the exception in thermodynamics, expecting anything more than 100% efficiency for most non-heat moving applications should not be expected.