What Is a Gigawatt-Hour (GWh)?

Gigawatt hour, abbreviated as GWh, is a unit of energy that represents one billion (1 000 000 000) watt-hours and is equal to one million kilowatt-hours. 

Gigawatt hours are mostly used as a measurement of the output of large electric power stations.

One gigawatt could power 10 million watt bulbs. With a much lower energy consumption, one gigawatt could power 100 million LED lights.

The U.S. currently generates about 135.7 gigawatts of electricity from solar panels. According to the Solar Energy Industries Association (SEIA), this is enough to power 24 million American homes. 

This is a significant increase from just over a decade ago when the country got less than one gigawatt of power from this renewable energy source.

How Is GWh Measured/Calculated?


Step 1: Determine the generator production capacity in megawatts and convert that to power production in MWh. If your generator capacity is 10 megawatts, it can yield 10 megawatts each hour, or 10 MWh.

Step 2: From that MWh figure, multiply it by 8,760 (the number of hours in a year). For this example, that would produce an annual production of 87,600 MWh.

Step 3: Divide the annual MWh figure by 1,000 to get GWh. The result would be 87,600 MWh/year, equalling 87.6 GWh/year.

Why Is It Important To Know About GWhs and Energy Usage/Conservation Measures?

GWh is an important unit of measurement for large-scale energy projects and utilities as it allows for the easy comparison of electricity production from different sources. 

It also provides a way to track progress in renewable energy generation and efficiency improvements.

For example, let's say that a new wind farm comes online and produces 100 GWh of electricity per year. 

We can then compare that to the average coal plant, which has about 700 GWh per year, or the natural gas plant, which produces 500 GWh per year.

This data can be used to decide where to invest in new energy generation projects and how to phase out older, less efficient plants.

Cumulative Global Energy Storage Deployments

According to the forecast from BloombergNEF (BNEF), energy storage installations worldwide were projected to reach a cumulative 358 gigawatts/1,028 gigawatt-hours online at the end of 2030.

This boom in stationary energy storage required more than $262 billion of investment, BNEF estimated.

Further, 345 gigawatts/999 gigawatt-hours of new energy storage capacity will be added globally between 2021 and 2030. 

This capacity amounts to more than Japan's total power generation capacity in 2020.

Over half of the global storage installations by 2030 will be carried out by the U.S. and China, which are considered the two largest markets. 

The clean power aspirations of state governments and utilities drive storage deployment in the U.S.

Meanwhile, in China, they are targeting a 30 gigawatt-installation cumulative build by 2025. 

Also, the stricter renewable integration rules augment expected storage installations.

U.S. Renewable Energy Projections by 2050

A dramatic increase in renewable energy in the power sector is expected over the coming decades. 

By 2050, 85% of power generation is projected to be achieved by renewable energy, mostly through solar and wind, a massive increase from 25% in 2017. 

This transformation requires new approaches to power system planning, system and market operations, and regulation and public policy.

The share of electricity occupied by end-use sectors would need to double from roughly 20% in 2015 to 40% in 2050 as low-carbon electricity becomes the primary energy carrier.

There is a need for increased renewable energy in the industrial, transport, and building sectors. 

These include an increased renewable electricity supply and solar thermal, geothermal energy, and bioenergy.

Energy efficiency is also critical in the building sector. Moreover, the slow rate at which energy efficiency in the industry is improving. 

This is because of the low building renovation rate of 1% per year of the existing building stock, which remains a major issue.

The global energy transformation is expected to cost $1.7 trillion annually in 2050. However, better health, cost-savings from reduced air pollution, and lower environmental damage would far outweigh these costs.

Final Thoughts

To achieve a greener future for our planet, it is important to know about GWh and understand energy conservation. 

This will help us make better decisions about where to invest in new energy generation projects.

Government and industry sectors can also use this information to track progress in renewable energy generation and efficiency improvements. 

By doing so, we can work towards a cleaner and more sustainable future for all.


1. What is a GWh?

Gigawatt hour, abbreviated as GWh, is a unit of energy that represents one billion (1,000,000,000) watt-hours and is equal to one million kilowatt-hours.

2. How is GWh calculated?

GWh is calculated by dividing the annual MWh figure by 1,000. For example, if a power plant produces 90,000 MWh of electricity per year, its GWh would be 90 GWh/year.

3. Why is it important to know about GWh?

GWh is important because it provides a way to measure and compare the energy output of different power plants. By understanding how much energy a plant can generate, we can make informed decisions about where to invest in new generation capacity.

4. What is the difference between GWh and MWh?

Gigawatt hours (GWh) and megawatt-hours (MWh) are both units of energy. MWh is equal to a million Wh or 1,000 kWh, while GWh is equal to 1,000 MWh.

5. How is GWh used?

GWh is commonly used to measure the annual output of power plants. It is also used to compare different power plants and understand new projects' potential capacity.


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