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

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What is a megawatt?

A megawatt is 1 million watts of power. Electricity generators are often measured in megawatts of peak power generation capacity.

What is a megawatt-hour?

A megawatt hour is one million watts of electrical power used for 1 hour. It refers to an hour of electrical energy equal to this amount.

The term megawatt-hour adds an element of the period of time for which the amount of electrical power is used, whereas the term megawatt simply refers to an amount of instantaneous electrical power.

Just like the term watt-hour and kilowatt-hours (kWh) adds a time element to the terms watt and kilowatt.

It can also be any variant of this for example 500,000 watts of electricity used for 2 hours would equal one megawatt-hour.

What is the abbreviation for a megawatt-hour?

The abbreviation for megawatt-hour is MWh.

How many kilowatt-hours are in a MWh?

There are 1000 kilowatt-hours in one megawatt-hour. Power plants produce too much electricity to easily measure in kilowatt-hours and so they measure electricity in megawatt-hours. However, the energy consumption of a typical home is better measured in kilowatt-hours.

What is the annual energy usage of an average home in America?

The amount of energy consumed by the average American home each year is 10.76 MWh's. Energy efficiency measures and better appliances have reduced the amount of energy used per square foot in the average American home, but as homes have become bigger over the last 30 years energy usage per home has still remained fairly constant.

How much solar power is needed to produce enough solar electricity to power a home?

If we take the average usage of an American home of 10.76 MWh's per year, then we need to know how much electricity solar panels produce in your state each year to work out how many solar panels you need. Obviously, solar electricity production depends on your climate and the access you have to sunshine. Solar panels typically produce between 1.1 MWh's of power per year in the northeast per kilowatt of peak DC capacity of installed panels up to as much as 1.5 MWh's of electricity in places like Arizona and Nevada.

As such this means the size of solar system you need to power an average American home will be in the range of a 6-9 kilowatt solar system.

How many kWh is 1 MW?

A megawatt is an instantaneous measure of power whereas a kWh is a measure of power used over time and so the two measurements, whilst related, are measuring different things. It is a bit like asking how many gallons in a foot… it just doesn't make sense, although both kWh and MW are electrical units of measurement.

When we talk about a kilowatt or a megawatt we are talking about an instantaneous measure of the amount of watts of power.

A watt of power is a measure of Current x Voltage:

P (watts) = I (current is measured in Amps)
V (Voltage measured in volts)

The better question to ask is how many kWh's in a MWh, which is 1,000.

How much is a megawatt of electricity worth?

According to the Energy Information Administration, the average cost of a kilowatt-hour of electricity in the residential sector in America is around 13.7 cents per kilowatt-hour. This means that the cost of 1 MWh of power for a homeowner is around $137. In some states, however, it can be more like $200 per MWh or $0.20 per kilowatt hour.

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


How much do solar panels for home cost to produce enough MWh's of solar energy to power your home?




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