Your best starting point is to determine how many kilowatts of power you need is to look at how many kWhs (kilowatt hours) home, business, or organization used in each of the previous 12 months. With this, we can compare expected monthly solar energy production to your electricity usage. Annual electricity usage total is also a good start. You’ll find your monthly kWh records via paper copies of your utility bills, a phone call to your utility provider, or through your online utility account.