Question: how much electricity does leaving a light on cost?
Answer: And while the numbers at the top may not be accurate in terms of how much is wasted by leaving a light switched on it is important to note that 1 kWh of electricity will power a standard 60W bulb for around 17 hours. While an 11W low energy bulb for around 90 hours and a 1W LED night light for around 1,000 hours.