On my commute tonight I did a 20 minute interval. My weight was 152lbs or 69 kg

Here is a screen shot from Training Peaks.

Power: YELLOW
Heart Rate: RED
Speed: BLUE
Cadence: GREEN

My Average Power was 221 watts / 69 kg = 3.20 w/kg
My Normalized Power was 249 watts / 69 kg = 3.60 w/kg

I felt good during the interval but after it I was spent for nearly 10 minutes. The interval was through a section that had traffic signals and a couple of rollers hence the spikes in power.