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2017 Archive of Measurements of Voltage Delivered to My Home

Graphical Monthly Summaries of My Voltage Measurements

What follows are separate charts for each month of 2017 showing the thousands of voltage measurements I have made at my wall outlet of the too much voltage delivered to my home and appliances by Hydro One.  The months are in reverse chronological order.

If you have questions or comments about any of the information here, please contact me

December 2017

Average voltage for the month of December was 122.17 VAC, about the same as it had been in July 2017.  See a summary of monthly voltages.

December 2017 was a bit unusual in that it followed November 2017 (well, no surprise there!) which broke the previously established trend of ever-increasing voltage, due in part to a power outage near the beginning of the month.  During December the voltage remained fairly constant but at a slightly lower level than had been expected, based on the previous trend. 

Here are some charts that illustrate the behaviour of the voltage at my home during December. 

History of voltage, Dec 2017

Some depression in voltage was probably due to the onset of very cold weather.  Also, notice the short break in readings near mid-month when it was not possible to make any measurements. 

Histogram of voltage, Dec 2017

Below is a chart of the voltage displayed as a function of the time-of-day of the measurement.  Midnight would be "0", noon would be "0.50" and the next midnight would be "1" day, so you can see how the voltage varies on average through a typical day during the month.

Voltages at time of day during Dec 2017

November 2017

November 2017 was an unusual month with a power outage that resulted in our voltage being reduced to 120 VAC on average, followed two weeks later by a sudden increase in voltage to what it had been before the outage.  Please see here for more specific details for November 2017. 

The charts below were calculated with data for the entire month and therefore represent 3 different populations of voltage samples : before the outage, after the outage but before the "resumption" of higher voltage, and after the resumption.  As a result, the histogram shows a bi-modal distribution in spite of there being over 300 samples, and the graph of voltage versus time of day is a spread-out mix of all three populations. 

Voltage history, November 2017 Voltage histogram, November 2017 Voltage at time of day, November 2017

October 2017

The trend to a higher average voltage has continued for another month. 

History of voltage measurements, October 2017. Histogram of voltages, Oct 2017. Voltages at Time of Day, Oct 2017.

September 2017

The gradual upward trend in average voltage continued this month, and one could see signs of the supply system struggling to provide a stable voltage during the several periods of unseasonably high temperatures in the province which placed unusual demands on the electricity supply system.  This is easily seen in the histogram of voltage supplied to my home. 

History of voltage during September 2017 Histogram of voltage, September 2017 Voltage at Time of Day, Sep 2017

August 2017

A gradual upward trend continued this month with the average voltage around 122.6 VAC.  This trend seems persistent and is, therefore, probably a result of Hydro One policy.  It will be interesting to see if the trend reverses when cooler weather arrives. 

History of voltage, August 2017 Histogram of voltage measurements, Aug 2017 Voltages at Time of Day, Aug 2017

July 2017

Voltages at my home moderated somewhat during July, averaging about 122.1 VAC.  Despite several spells of very warm weather, the range of voltages seen did not increase from previous months.  The average voltage is still higher than I would prefer. 

History of voltage during July 2017 Histogram of voltages during July 2017 Voltages at time of day, July 2017

June 2017

Voltages were significantly higher this month than they have been, in fact, highest since the end of that terrible (voltage-wise) winter of 2015-16.  The recent increasees definitely look like a trend!  See the chart on the summary page

Chart of voltage history, June 2017. Chart of histogram, June 2017. Chart of voltage versus time of day, June 2017.

May 2017

Voltages seem a little higher this month.  I hope it isn't the start of a trend.

Voltage history, May 2017 Voltage histogram, May 2017 Voltage at time of day, May 2017

April 2017

Voltages during April were about the same as during March, helping to establish a definite levelling off of the voltage supplied by Hydro One.  It will be interesting to see if this level of voltage can be maintained during the coming summer months when the system is stressed by the impacts of hot and humid weather. 

History of voltage, April 2017 Histogram of voltage, April 2017 Voltage at time of day, April 2017

March 2017

March showed a slight relaxation in the trend to a higher average voltage and the average voltage seems now to be stable at a value between 121 and 122 VAC.  Sure wish they had done this during the winter of 2015/16!  As noted in February, the difference in voltage between day and night is much less now than before. 

History of voltages, March 2017 Histogram of voltages, March 2017 Scatter diagram of voltage at time of day, March 2017

February 2017

February saw a continuation of the trend to rising voltages since last summer.  The average voltage is still less than 122 VAC but not by much (121.86 VAC).  I suppose that Hydro One hopes that I will become bored and stop watching them.  (As a confirmed data junkie, I am unlikely to do that!).  Curiously, the day/night difference is much less clear now than before (see the Time of Day scatter diagram). 

History of voltage, Feb 2017 Histogram of voltage, Feb 2017 Scatter diagram of voltage at time of day, Feb 2017

January 2017

Voltages observed during January 2017 were much better behaved than a year ago and were almost normal by comparison, averaging near 121 VAC instead of 124 VAC.  Whether this was due to some new customer-friendly policy at Hydro One or was dictated by some technical circumstance of supply and demand, I do not know.  Compare the three charts below with those for January 2016, further down. 

History of voltage, Jan 2017 Histogram of voltages, Jan 2017 Scatter diagram of voltages measured at time of day, Jan 2017

Got Data?

If you have voltage measurements from your own neighbourhood and would like to share them, please contact me and I would be glad to exchange raw data and other results with you. 

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