You may hear various claims about a power source
being "enough to power x number of homes." But is that really an
accurate and useful way of determining how much power is really produced?
After all, the amount of electricity a home uses will vary greatly, from as
little as a few watts when nobody is home, to a few kilowatts, if one is cooking
on an electric stove, running the air conditioner and the refrigerator is
running. If you're sitting home watching TV and there are a
few lights on, you could be using a couple hundred watts. Add a
couple hundred more when the fridge comes on. And if you have a PC,
that could be anything from 200 watts to nearly a kilowatt. (one kilowatt)
How much power a home uses depends on many factors and changes constantly.
The "Average" power usage is really not as relevant to reality as it may seem,
especially given how much it can change from season to season. And
time away from home or sleeping can skew that average by a lot.
So here's another way to put the amount of power
produced from a given source in context. Just ask "What kind of
generator would it replace." In other words, if a wind farm
produces, for example four to eight kilowatts, that means that enough energy is
generated that a large diesel engine could be replaced, something about the size
of a locomotive. If a wind farm produces a half gigawatt,
that's enough for a moderately sized power plant to be turned off.
 |
6-10 Kilowatts: Gasoline or small diesel generator. Residential backup, remote site, construction, portable power, events etc. |
 |
100 Kilowatts: Small Commercial diesel generator. On-site or mobile. Larger construction, floodlighting, special events, backup for small offices, municipal or public safety buildings, public schools etc.
|
 |
1-2 Megawatts: Medium Commercial Generator. Backup power for schools, small to medium office buildings, police or public safety buildings, larger medical clinics or small hospitals, data centers.
|
 |
4-8 Megawatts: Single large diesel generator. Backup power for hospitals, data centers, phone exchanges, larger municipal buildings, emergency services, small factories in regions with unreliable power. |
 |
10-20 Megawatts: Small private generating plant. Government facilities, military installations, small remote communities, telephone and data switching stations, broadcasters, large hospitals. |
 |
40-80 Megawatts: Small power plant. Either using several diesel generators or a small steam turbine. Remote communities, such as islands, military bases, "distributed power generation" for times of power shortages, office complexes. |
 |
100-200 Megawatts: Small hydroelectric power station. Often built primarily for floor control, navigation or irrigation, dams on small to medium rivers may produce electricity as an added benefit. Thousands of small hydroelectric facilities ranging from a few megawatts to one hundred or more operate in the United States. |
 |
200-500 Megawatts: Medium sized combined cycle power plant. Other power plants, fired by coal, natural gas, oil or other. Used for peak
power demands or occasionally as a major source of electricity,
these power plants are medium by current standards. |
 |
1+ Gigawatt: Large power plant, providing grid power. Usually coal burning. These provide over half of the power in the United States and often burn so much coal, that between one and four mile-long coal trains must unload their contents daily to keep the plant fueled, when under full load. |
 |
2 Gigawatts: Full sized nuclear power plant or very large coal fired power plant. These represent some of the larger power plants and can often be the largest grid power source for a given region. Some may produce as much as three gigawatts at full capacity. |
 |
3 Gigawatts: Single very large hydroelectric installation, such as the Hoover dam. There are few rivers remaining suitable for this sort of scale of power generation and none in the United States. However, nations like China are planning on creating mega-dams which could produce tens of gigawatts. |
 |
4.5 Gigawatts: Combined total output of the power stations built at Niagra falls. Harnessing the power of water diverted from the falls, the power plants at Niagra generate much of the electricity used in New York State and Ontario Canada. |