I still wonder if heating a house with transistor is efficient. Gotta ask a scientist I guess. I mean there must be energy spent switching transistors back and forth.
Yes, there can be heat pump systems with e.g. underground connections, and pumping heat can be more effective than generating heat; but for pure heating, generating heat, the simplest resistor heater is just as 100% efficient as any complex electronic device, all the electricity spent results in just as much heat.