Energy Metering: How Much Electricity Does My Home Office Consume In A Month?

I keep a list of overhead expenses that I update from time to time in my office. It helps me determine how much I need to charge for a day’s work. Most items on that list are easily quantifiable, except for the electricity cost.

I have worked from home since I started as a sole proprietor in March 2015. I chose a home office setup not because I predicted a pandemic would occur five years later but because it was the most practical way to get started as an architectural practitioner.

My office is inside my bedroom, and I did not bother installing a submeter. I would love to have it, but I didn’t have the time to be concerned with re-wiring works back then. Not to mention the cash I need to shell out to make it happen. Besides, I am a one-person team that would only require minimal office equipment to get the job done. So for the longest time, I allot a fixed amount for electrical expenses without measuring how much I consume because there’s just no means other than going over the trouble of calculating it manually.

Recently I came across a device capable of doing what a submeter does and much more. A “smart socket,” as the merchant calls it, is a device that turns your existing “dumb” power outlets into a “smart” one. When connected to your home’s WiFi, it allows you to control the appliance plugged into it wirelessly. The regular variant lets you turn it on and off on-demand or through a preset schedule via a smartphone app or voice command. The other variant, which piqued my interest, has an energy monitoring capability that records the appliance’s energy consumption in real-time. I took the plunge and purchased several. I plugged all of my office equipment into it, measured the energy consumption for twenty-six (26) working days, and tallied the results.

My workstation setup

My typical working hours are from 8:30 AM to 6 PM Monday to Saturday. I use the following equipment: 

1. Laptop (51 Wh battery) 
2. HD webcam, USB
3. Condenser microphone, USB
4. LED monitor screen bar lamp, USB
5. Keyboard, bluetooth, rechargeable
6. Mouse, WiFi and bluetooth capable, rechargeable
7. USB fan 
8. LED IPS monitor, 24″ (25 W)
9. Multimedia speakers with subwoofer (9 W)
10. WiFi mesh device
11. Desk lamp with 7 W LED bulb
12. DC stand fan (25 W max. consumption)
13. Mobile phone, 3200 mAh battery
14. Mono headset, bluetooth, rechargeable
15. Power bank, 20,000 mAh, two pieces
16. Battery charger
17. Air purifier

As a sole practitioner architect, master plumber, and green building auditor and consultant, my workflow does not involve 3D modeling. I have trusted colleagues who do it for me for a fee.

Note

3D modeling on computers consumes more electricity than 2D designing and detailing.

Smart socket distribution

I have three smart sockets:

1. One for the laptop where the peripherals were connected (webcam, condenser microphone, keyboard, mouse, and USB fan)
2. One for the air purifier, and
3. One for all other devices where I plugged them into an extension cord with multiple sockets and USB ports (LED IPS monitor, LED monitor screen bar lamp, multimedia speakers, WiFi mesh device, desk lamp, DC stand fan, and rechargeable devices)

Then I set a schedule via the smart home app. The sockets turn on at 8:30 AM, turn off at 12 NN, and turn on again at 1 PM. I record the consumption of each socket at 6 PM.

The results

I recorded and tallied the energy consumption for twenty-six working days from April 01 to 30, considered one of the Philippines’ hottest months. The prevailing price of electricity where I live and work is PHP13.71 per kilowatt hour (kWh) as of April 2022. That includes all other charges aside from the generation and transmission costs. I took the total amount in our electricity bill and then divided it by the total kWh consumption to arrive at the price per kWh. Here are the results:

Conclusion

The data shows that my home office has consumed 17.77 kWh of electricity from April 01 up to April 30, operating at eight and a half hours for twenty-six working days. That is approximately PHP243.63 or PHP9.32 per day or PHP1.10 per hour. But as you may know, sole practitioners have indefinite working hours. I have recorded my electricity consumption for working hours before 8:30 AM and beyond 6 PM, and needless to say, the amount is more than what I disclosed here. Nevertheless, I can now precisely determine my electricity consumption, which I couldn’t do before. It’s time to update my overhead expenses with new data.

Take-aways

With the advent of smart home devices, we can finally measure electricity consumption effortlessly. Knowing how much electricity we consume in real-time also increases our awareness, which may contribute to energy-saving efforts later on. As they say, you can only manage what you can measure.