Part 1 : Data description:

The Data was recorded between September 20th, 21:01:42 and October 10th, 13:00:47.

There is one record every 10 minutes.

The created Excel files contains 2 features :

• The date of the record, format yyyy-mm-dd hh:mm:ss

• The Electric consumption (in Wh) through the smart socket, in the 10 min interval before the indicated time. 

Part 2 : Data Cleaning and outliers

Data was mostly clean, no missing data, no repeated time code.

I divide the date column in three features : the day of the week, the date, and the time.

Looking at the line chart of the consumption, I see one outlier :

Whereas the consumption, in 10 minutes, is always under 20Wh, it reached more than 100Wh the October 10th, around 6:30pm.

After looking at the date, it is the time where I put my vacuum cleaner on the power board instead of the mural socket on the other side of the room.

So at look at the average consumption during the day :

Part 3 : Patterns

I changed the y-axis to keep only the time where consumption was under 20Wh.

We can distinguish three main behaviours: when the socket is off during the night (green), when only the Wi-Fi box is on (yellow), and when we are using TV (orange).

To have more precise analysis, I can filter by date, to see the difference induced by the presence of my daughter at home (she watches one cartoon in the morning, one in the afternoon) or at the day care (I sometimes watch TV in the morning, and almost anytime at lunch).

Part 4 : Answer the question

The average consumption, at intervals of 10 minutes, between 7 a.m. and 7:59 a.m. every morning is 4.72225758 Wh.

That gives me an average power of 28.40 W

The socket is off every night for 7 hours (from 11:30 p.m. to 06:30a.m.)

And my actual price of electricity is $0.39955/kWh.

So, each night allows me to save: $0.08.

To reimburse the power socket, bought $69, I will need 869 night, or 2 years, 4 months, and 17 days.

Part 5 : Conclusion

My answer doesn’t include increase of electricity rates. Data about past electricity rates could allow me to forecast the cost for the next 2 years and improve my result.

Moreover, I don’t know the durability of the smart socket.

I need to continue thinking about it…'