Watts per hour (W/h) is not a standard unit of measurement. Watts (W) are a unit of power, and they represent the rate at which energy is used or transferred per unit of time. So, when you say “100 watts per hour,” it doesn’t have a specific meaning on its own because it’s like saying “100 units of power per hour,” which isn’t a common or meaningful measurement.

If you’re looking to measure energy usage over time, you would typically use the unit of watt-hours (Wh) or kilowatt-hours (kWh). A watt-hour is a unit of energy equal to using 1 watt of power for 1 hour. Similarly, a kilowatt-hour is equal to using 1 kilowatt (1,000 watts) of power for 1 hour.

So, if you want to calculate energy usage over time, you would need to provide more information about how long you’re using the 100 watts of power. For example:

- If you use 100 watts for 1 hour, it would be 100 watt-hours (Wh).
- If you use 100 watts for 2 hours, it would be 200 watt-hours (Wh).
- If you use 100 watts for 1 hour every day for a month, it would be approximately 3,000 watt-hours or 3 kilowatt-hours (kWh) for the month.

To calculate the energy usage in watt-hours, multiply the power in watts (100 W in this case) by the time in hours that the power is being used.