Preliminary steady-state analysis

I've collected data for the total power demand of a home sampled at 1 second intervals for a 24 hour period. Here's the plot:

There are loads of peaks at around 2000 W, which are easy for a human to recognise. I wanted to pick these positive and negative step changes out automatically, so I wrote a script to calculate the difference between adjacent power readings, and if the difference was greater than 1000 W, record them. I've plotted the result:

I was hoping to see each red dot sitting roughly level with at least one blue dot and visa versa. This would mean that the step change for the appliance as it turns off is roughly the same as when it turns on. However, very few of red and blue dots actually sit on the same level, and even worse there's not even the same number of red as there are blue.

Tomorrow I'm planning to compare readings within a window, instead of using adjacent readings.