How to calculate equipment power consumption？

First, confirm the power parameter of the device, and then multiply it by the corresponding working time to calculate the power consumption of the camera.
W=p.t, take the camera DS-2CD3T45 as an example, the maximum power is 7W, working for 1 hour (equal to 3600 seconds), the power consumption is
W=p.t=7*1*3600=25200 Joule
25200/(3.6*10^6)=0.007 kWh
It can be seen that the power consumption per hour is about 0.007 kWh.
Note: The unit of W is Joule (the general unit is kilowatt-hour, commonly known as degree, which needs to be converted after calculation, 1 kilowatt hour = 1 degree = 3.6 multiplied by 10 to the 6th power of Joule)