What is a Megawatt (MW) and what is a Megawatt hour (MWh)?

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A Megawatt is simply 1,000,000 watts of electricity or 1000 kilowatts of power. A watt of electricity is a measure of power.

Power in turn is a function of the voltage of a circuit multiplied by the current.

Power= Current (Amps) x Voltage
Current =I
Voltage= V
P= IxV

A Megawatt hour is a measure of total energy and it refers to the amount of energy over a period of time:

1 Megawatt hour is equivalent to 1,000,000 watts of power being used or generated for one hour.

So if you were generating 1,000 watts for 1,000 hours you would generate 1 Megawatt hour (MWh).

If you were generating 10,000,000 watts for 6 minutes continually then you would generate 1 Megawatt hour (MWh).

Megawatt hours is the standard unit in which power is bought and sold at the wholesale level in contracts between power generators and utility companies. It is not the unit of power that you would typically see on your bill.


Find out how much a solar system produces in your area!


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How many Megawatt hours of power does the average house use?

The stats we have on this are based on users of our website who are typically owners of single family homes and given their interest in installing solar panels probably have larger than average usage but from our numbers the average usage of power is around 750 kWh per month, or 9,000 kWh per year. This 9 MWh per year.

Our Solar-Estimate solar estimator has all the rates schedules for almost every utility in America in its database and so if you know how much you spend a month on power we can reverse engineer this number to get an approximation of the amount of MWh of power you use per year. From this we can also give you an estimate of the size of solar power system you would need to zero out the usage charges on your power bill.


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