watt-hour
noun
: a unit of work or energy equivalent to the power of one watt operating for one hour
Examples of watt-hour in a Sentence
Recent Examples on the Web
Sun pointed out that the resulting batteries demonstrated a potential energy density exceeding 500 watt-hours per kilogram at the cell level, a power level that could enable electric vehicles to achieve a much longer driving range per charge.
—
Prabhat Ranjan Mishra, Interesting Engineering, 30 Oct. 2025
In fact, a U.S. Department of Energy study found that when the U.S. extended daylight saving by four weeks in 2008, electricity use dropped by about 0.5% a day — roughly 1.3 trillion watt-hours, or enough to power 100,000 homes for a year.
—Evan Moore, Charlotte Observer, 29 Oct. 2025
The carbon itself had an energy density of 65 watt-hours per kilogram, also in line with commercial supercapacitors.
—Perri Thaler, IEEE Spectrum, 22 Oct. 2025
The new rule also sets a size limit of 300 watt-hours per battery, with a grace period for larger batteries until Jan. 11, 2026.
—Michael Salerno, AZCentral.com, 20 Sep. 2025
The policy also restricts the size of lithium batteries eligible for transportation on Southwest flights, to 300 watt-hours or less.
—Zach Wichter, USA Today, 15 Sep. 2025
The Yoga's 75-watt-hour battery—generous for a 14-inch laptop—and energy-efficient chipset overcame the machine's power-hungry high-resolution OLED display.
—Mark Coppock, PC Magazine, 11 Sep. 2025
As noted in the previous article AI Prompts Drive Massive Hidden Costs in Energy and Water, a single Gemini prompt consumes about 0.24 watt-hours of electricity which looks trivial in isolation.
—Dianne Plummer, Forbes.com, 28 Aug. 2025
It's powered with a 720-watt-hour battery, which Rad Power estimates will get you to over 100 km (65 miles) of range at low assist settings.
—John Timmer, ArsTechnica, 12 Aug. 2025
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Prabhat Ranjan Mishra, Interesting Engineering, 30 Oct. 2025
In fact, a U.S. Department of Energy study found that when the U.S. extended daylight saving by four weeks in 2008, electricity use dropped by about 0.5% a day — roughly 1.3 trillion watt-hours, or enough to power 100,000 homes for a year.
—Evan Moore, Charlotte Observer, 29 Oct. 2025
The carbon itself had an energy density of 65 watt-hours per kilogram, also in line with commercial supercapacitors.
—Perri Thaler, IEEE Spectrum, 22 Oct. 2025
The new rule also sets a size limit of 300 watt-hours per battery, with a grace period for larger batteries until Jan. 11, 2026.
—Michael Salerno, AZCentral.com, 20 Sep. 2025
The policy also restricts the size of lithium batteries eligible for transportation on Southwest flights, to 300 watt-hours or less.
—Zach Wichter, USA Today, 15 Sep. 2025
The Yoga's 75-watt-hour battery—generous for a 14-inch laptop—and energy-efficient chipset overcame the machine's power-hungry high-resolution OLED display.
—Mark Coppock, PC Magazine, 11 Sep. 2025
As noted in the previous article AI Prompts Drive Massive Hidden Costs in Energy and Water, a single Gemini prompt consumes about 0.24 watt-hours of electricity which looks trivial in isolation.
—Dianne Plummer, Forbes.com, 28 Aug. 2025
It's powered with a 720-watt-hour battery, which Rad Power estimates will get you to over 100 km (65 miles) of range at low assist settings.
—John Timmer, ArsTechnica, 12 Aug. 2025
Cite this Entry
“Watt-hour.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/watt-hour. Accessed 12 Nov. 2025.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
Share