Question: how much electricity do solar panels use?
Answer: Typically, homeowners in the United States use about 900 kWh a month on average. So, take 900 kWh and divide by the amount of kWh one solar panel produces over the course of a month (30kWh), and you get a 30 panel installation. 30 panels x 250 watts per panel equals a 7,500 watt system (7.5kW).