We know that power consumption or Energy is

```
E = Power x Time

```

for utility billing, we used

```
E = kWatt x Hour

```

But I am not sure how to get the total Energy if we will based it per second having different power over a period of time.

```
0.5 Watt (time check 5:00:00 AM)
1.0 Watt  (time check 5:00:04 AM)
0.7 Watt  (time check 5:00:07 AM)
and so on.

```

Let say I wanted to calculate the energy from 5:00:00 AM - 5:00:07 AM

Is this the right calculation?

```
E1 =  0.5 x 4 = 2.0 Watt-sec
E2 =  1.0 x 3 = 3.0 Watt-sec
E3 =  0.7 x 1 = 0.7 Watt-sec

E1 + E2 + E3
2 + 3 + .7 = 5.7 Watt-sec
           = .00158 Watt-Hr

```

I just want to know if my calculation is right.
Thanks