Kilowatts and Kilowatt Hours

Let’s not make this any more difficult than it needs to be – it’s actually quite easy! A kilowatt (kW) is a measure of energy – 1000 watts. Everything that plugs into the wall uses a certain amount of watts per hour. A cell phone charging, for example, takes about 2 – 6 watts. So if you have a 5-watt phone/phone charger and plug it in for a full hour, you’re using 5 watt-hours. You’d have to plug in 200 cell phones charging heavily for a full hour to use a kilowatt of power. That would equal 1 kilowatt hour.

So a kilowatt hour is just an energy requirement of a kilowatt used over one hour. Your electric company bills by the kilowatt hour. The reason is that it doesn’t make sense to charge you for a “kilowatt” – you’re using a kilowatt of power every second the 200 cell phones are plugged in, so we need to specify a time period to determine how much energy you really used.

Let’s say you have a clothes dryer that takes 2,000 watts (2 kW) to run. If you run it for a full hour, your electric company would charge you for 2 kilowatt hours (kWH) of power. If you ran it for a minute, you’d still be using 2 kW – but it would be 1/60th of a kilowatt hour.

Kilowatt Solar Systems

In solar panel terminology, the kilowatt rating of a system is a little different. A 5kW system produces roughly 5 kW per hour of sun under normal conditions. So with 6 hours of sun you can produce 30kW per day, which is about the average of 30kW per day used by the average American. Most 5kW solar systems can actually produce more per day under ideal circumstances: great wiring, efficient equipment, sunny weather, and no shade.

How Much Does My Electric Company Charge per kWH?

Electricity rates vary by state, but this is the average for your state:

State Avg. Price per kWh Avg. Monthly Bill
Hawaii $0.37 $190.36
New York $0.19 $113.17
Alaska $0.18 $114.56
Connecticut $0.18 $132.07
Vermont $0.17 $97.50
New Hampshire $0.16 $102.66
California $0.16 $90.19
Massachusetts $0.16 $100.97
New Jersey $0.16 $108.10
Rhode Island $0.15 $91.48
Michigan $0.15 $96.95
Pennsylvania $0.14 $124.29
Maine $0.14 $79.13
Wisconsin $0.14 $95.21
Maryland $0.13 $136.63
Delaware $0.13 $122.25
District of Columbia $0.13 $90.51
Nebraska $0.12 $125.71
Ohio $0.12 $107.07
South Carolina $0.12 $134.86
Colorado $0.12 $84.91
Nevada $0.12 $109.94
Minnesota $0.12 $96.51
Arizona $0.12 $122.85
New Mexico $0.12 $76.56
Kansas $0.12 $107.85
Georgia $0.11 $124.67
Texas $0.11 $133.33
Florida $0.11 $121.53
Alabama $0.11 $136.36
Missouri $0.11 $121.98
Iowa $0.11 $100.30
Indiana $0.11 $110.44
North Carolina $0.11 $120.52
Virginia $0.11 $125.36
Mississippi $0.11 $131.49
Illinois $0.11 $80.57
Utah $0.10 $82.79
Montana $0.10 $88.85
South Dakota $0.10 $108.21
Wyoming $0.10 $90.85
Tennessee $0.10 $124.25
Oregon $0.10 $96.58
Kentucky $0.10 $112.95
Oklahoma $0.10 $110.55
Arkansas $0.10 $108.64
West Virginia $0.10 $106.44
Louisiana $0.09 $119.98
Idaho $0.09 $98.35
North Dakota $0.09 $109.85
Washington $0.09 $90.55