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# Energy at NYU:FAQ

Who is this website for?
This website is for students, faculty, administrators, and staff of NYU who need or would like to know about building energy performance on campus. However, it may also be of interest to those outside the NYU community who would like to learn more about NYU's efforts to increase building operating effeciency.

What information can be found on this website?
This website shows electricity usage data for certain buildings for certain time periods. It does not show energy use other than electricity, or every building at NYU. This is because our smart meters only capture electricity data and at this time they are not present in every building.

What is the difference between a kilowatt (kW) and a kilowatt-hour (kWh)?
Kilowatts (kW) measures how much electricity comes through the electrical service wires into the building. For instance, turning on more lights at the same time will cause the smart meter to read a higher number of kilowatts being used by the building at that moment. This is called "demand." Your apartment might demand 4 kW from the grid when you are home and using appliances, and only 0.5 kW when you are away and things are turned off. A kilowatt is 1000 watts.

Kilowatt-hours (kWh) measure how much electricity was consumed by the building over a period of time. For instance, in a day, your home might consume 10 kWh, and over the month it might consume 300 kWh. A kilowatt-hour is 1000 watt-hours.

A 25 watt compact fluorescent light bulb (CFL) running for 40 hours consumes 1 kWh (25 watts times 40 hours is 1000 watt-hours, or 1 kWh). This is the same energy consumed by a 100 watt incandescent bulb running for only 10 hours (100 watts times 10 hours is the same 1000 watt-hours or 1 kWh). Since those two bulbs put out the same amount of light, you can tell that you can run the CFL four times as long for the same energy consumption.

Consumption is calculated: consumption (kWh) = demand (kW) x time (h).

The smart meters calculate consumption from demand by averaging the demand (kW) every 15 minutes and multiplying that by the associated time frame of a quarter of an hour (.25):
kWh = (avg kW for past 15 mins) x .25
150 kWh = 600 kW x .25