1 - In the 1930's they didn't have everything we have now , They had electric cars and now we have cars that run on gas . They hardly used any energy at all .
2 - Well insulation can be heaters , air conditioning and all kinds of things but some heaters & Air conditioning have to be plugged in . But I'm pretty sure things that are plugged in take more energy .
3 - I learned to not put your fingers in sockets because I've done it and it hurts . Also , Some things will shock you if you don't plug them in or take them out right .
4 - Trees & Oil .