In the 1970s a typical British home would only have had 17 objects requiring power such as electricity.
(Things like: television, vacuum cleaner, electric bar heater, hi-fi system, hairdryer, electric kettle, washing machine, iron, electric blanket, radio, sewing machine, cooker, cassette player, fridge, DIY appliances, toaster, occasional lamps. And of course there would only be one TV. Unimaginable.)