Gigajoules to Watt-hours conversion

How to convert gigajoules to watt-hours?

Certainly! Let's start with the conversion from gigajoules to watt-hours.

Conversion from Gigajoules to Watt-hours

1 gigajoule (GJ) is equal to 1,000,000,000 joules (since a "giga" is 10^9).

1 joule is equal to 1 watt-second (W⋅s).

To convert watt-seconds to watt-hours (W⋅h), you need to divide by the number of seconds in an hour.

There are 3600 seconds in an hour.

So, the conversion steps are:

$\text{1 GJ} = 1,000,000,000 \, \text{joules}$ $1,000,000,000 \, \text{joules} = 1,000,000,000 \, \text{W⋅s}$ $1,000,000,000 \, \text{W⋅s} \div 3600 \, \text{s/hour} = 277,777.78 \, \text{W⋅h}$

Therefore:

$1 \, \text{GJ} = 277,777.78 \, \text{Watt-hours (W⋅h)}$

Real-World Examples

1. Household Energy Usage:

   • A typical household in the U.S. uses about 877 kWh (kilowatt-hours) per month.
   • 1 GJ is approximately 278 kWh.
   • So, 1 GJ can power an average household for about 1/3 of a month.

2. Automotive Fuel:

   • 1 liter of gasoline contains roughly 34.2 megajoules (MJ) of energy.
   • So, 1 GJ would be equivalent to the energy in about 29.2 liters of gasoline (1000 / 34.2 = ~29.2).

3. Food Energy:

   • A typical adult needs about 2,000 kilocalories (kcal) per day.
   • 1 kcal is approximately 4.184 kJ.
   • So, a day's worth of food energy is about 8.37 MJ.
   • 1 GJ would be equivalent to roughly 119.41 days' worth of food for a typical adult (1000 / 8.37 = ~119.4).

4. Electric Vehicles:

   • A Tesla Model 3 has a battery capacity of around 75 kWh.
   • 1 GJ can charge the battery approximately 3.7 times (278 / 75 = ~3.7).

5. Lighting:

   • A 10-watt LED light bulb consumes 10 watts per hour.
   • So, in 1 hour it uses 10 Wh.
   • 1 GJ equals 277,777.78 Wh.
   • So, 1 GJ can keep the LED light bulb running for roughly 27,777.78 hours.

These examples give you a sense of how much energy 1 gigajoule represents in various contexts and how it can be applied to everyday real-world situations.