I overheard a very interesting conversation while in a lift. I heard one guy saying: The lift takes more energy to take a person going down than a person going up. The logic is that the lifts usually have a big counter-balance attached to it. The counter-balance always goes in the opposite direction of the lift. If the lift goes up, the counter-balancing weight goes down and vice-versa. So while you and the lift has to go down, the heavy counter-balance has to be lifted and hence is very energy intensive. So the next time, walk down and go up in lift to save some electricity.