What is gigawatt?

A gigawatt is a unit of power equal to one billion watts. It is used to express the total power output of national electricity grids, large power stations, and national energy policy targets.

Real-world uses

Gigawatts describe the generating capacity of entire national grids, large hydroelectric dams (Three Gorges Dam: ~22.5 GW), and the total installed solar or wind capacity of countries. Global electricity demand is often expressed in terawatts (1,000 GW). Energy policy discussions use GW to compare national ambitions.

History

Gigawatts entered common use in discussions of national and continental electricity systems during the 20th century. As installed generation capacity in large countries reached the gigawatt scale, this unit became standard for energy policy, grid planning, and international energy statistics.

Common mistakes

Confusing GW (power) with GWh (energy). A 22 GW dam running at full capacity for one hour generates 22 GWh of energy. Also, the pop-culture reference "1.21 gigawatts" from Back to the Future is frequently cited but would equal about 1,210 MW—a large power plant.

What is BTU per hour?

BTU per hour is a unit of power used to measure the heating or cooling capacity of HVAC equipment. It is the standard rating system for air conditioners, furnaces, and heat pumps in the United States.

Real-world uses

BTU per hour is the standard power unit for rating furnaces, air conditioners, heat pumps, and boilers in the United States. A residential central air conditioner might be rated at 24,000–60,000 BTU/h. In casual use, the "/h" is often dropped, so "12,000 BTU air conditioner" actually means 12,000 BTU/h.

History

BTU/h became the standard power unit for the US HVAC industry during the post-World War II residential building boom, as central air conditioning and forced-air heating became widespread. Industry standards bodies such as AHRI codified BTU/h ratings for equipment comparison.

Common mistakes

Dropping the "/h": confusing BTU (energy) with BTU/h (power) is extremely common in HVAC contexts. A unit absorbing 12,000 BTU in one hour is operating at 12,000 BTU/h of capacity. Also, 1 ton of refrigeration = 12,000 BTU/h, which can cause confusion in capacity comparisons.

When is this conversion used?

Converting between gigawatt and BTU per hour is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.

Worked examples

1 gigawatt = 3.412142e+09 BTU per hour

1 BTU per hour = 0.29307107 watt

How to convert gigawatt to BTU per hour

To convert gigawatt to BTU per hour, multiply the value by 3.412142e+09.

To convert BTU per hour back to gigawatt, multiply by 2.930711e-10.

Measurement standards

The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.

Did you know?

The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.

Quick reference: gigawatt to BTU per hour

Common values

Available Power units

• watt conversions
• kilowatt conversions
• horsepower (mechanical) conversions
• megawatt conversions
• gigawatt conversions
• milliwatt conversions
• microwatt conversions
• BTU per hour conversions
• kilocalorie per hour conversions
• ton of refrigeration conversions

More gigawatt conversions

• Convert gigawatt to watt
• Convert gigawatt to kilowatt
• Convert gigawatt to horsepower (mechanical)
• Convert gigawatt to megawatt
• Convert gigawatt to milliwatt
• Convert gigawatt to microwatt
• Convert gigawatt to BTU per hour
• Convert gigawatt to kilocalorie per hour
• Convert gigawatt to ton of refrigeration

Assumption: horsepower values use mechanical horsepower.