Edwards Technical Writing

Solar power for my office is working very well!

Sunday, Feb 7, 2021
It was a beautiful sunny day in Victoria, BC. Solar input was consistently 60W all afternoon. When the sun went down my laptop was fully charged, and both lithium ion batteries were charged to 100% capacity, meaning I started the work week at 9 am on Monday morning with 660W of stored power, and a fully charged laptop. 

Monday, Feb 8, 2021
When my batteries are fully charged, there is no capacity for storage, and my solar power generation is zero. I have been working on my laptop for several hours. There is no need to use a desk light today. At lunch time my laptop battery is 95% and my lithium ion batteries are at 100%

To be as sustainable as possible, I try not to run a printer, and either read docs on my laptop screen or add them to my Dropbox™, which is synchronized with a kobo e-reader (charged using solar generated power). 
At 3 pm: solar output (running laptop, inverter, desk light, and charging cell phone) was 30W. Input was 5W. Battery charge = 100% (I know that doesn’t add up, I can’t explain it). Reports of brief snow in Vancouver, but no snow, or precipitation of any kind, in Victoria!

End of Day Monday: Lithium ion batteries charged 100%, laptop 88%; phone 52%

Tuesday, Feb 9, 2021
9:00 am: Solar power generation = 2W at 9:00 am; running laptop on its own battery. Today, in addition to my regular work activities, I have two webinars (total duration = 3 h). Total stored energy = 660W.
Lunchtime: Input = 33W; output = 25W (desk light and webinar). Lithium ion batteries still charged 100% (660W stored). 

End of Day Tuesday: Lithium ion batteries charged 90% (594W stored)

Wednesday Feb 10, 2021 
Despite snow, solar generation has stayed within 5 to 10W all morning. Both lithium ion batteries were 90%charged at the start of the day. Considering that the next sun in the forecast is one week away; I plan to conserve the stored power by using my laptop monitor only, and not using a second monitor.
Mid-day: Input = 6W; output = 5W

End of Day Wednesday total stored power = 539.6W; Laptop battery charged to 85%.

It’s winter, solar input is consistently low (<5W) with occasional sunny periods. I don’t think input and output details throughout the day are useful. I’m just going to estimate the quantity of stored energy at the end of each work day, and see how long I can power my office on solar power alone. Moving forward updates will be the total Watts of stored energy at the end of each work day, or when the sun goes down.

Thursday EOD (end of day): Total stored energy from solar generation = 565.2W

Friday EOD: Total stored energy = 558.8W

This weekend it snowed heavily in Victoria. Therefore no solar power generation to charge my batteries. Total stored power  usage for the week (Feb 8 – 12) = 101.2W. It is raining now, but I hope to top up my batteries, and keep the office running on solar power, even with low winter light levels. 

Week starting: Monday February 15, 2021

9 am Monday: total stored power = 542W

Feb 16: EOD total stored energy = 461.6 W

Feb 17: EOD total stored energy = 565W

Feb 18: EOD total stored energy= 418.4 W

Feb 19: EOD total energy storage = 372.6 W

Feb 22: 9 am total stored energy = 404.6 W

The last two weeks of dull, and dreary, BC winter, have included snow, rain, and some sun; The total stored power has been depleted by 118 W and 137.4 W per week respectively. It is reasonable to assume that running a full time office with multiple Zoom meetings per day, a desk light, a fully charged laptop, that is running the full suite of MS Windows, is connected to the internet by Wi-Fi, and is keeping a phone charged, will need up to an additional 140 W of power most weeks. This means that once the batteries are fully charged, during winter, I can expect to keep the office running on solar for five weeks without a top up.
Today was a beautiful sunny day, and I stored an extra 147 W of power. If tomorrow is similar, my lithium ion batteries will be fully charged by the end of day (EOD).  This winter was a bit of an experiment to see if I could keep running my office on solar, in dull, grey, BC, and the answer is heck yes!