By Kristen Abels

It’s that time of year again… the days are at their shortest, the weather at its coldest – indeed, the Canadian winter has arrived! While this season might be a little gloomier than most, the holiday lights are still up and shining just as bright, bringing some much-needed joy and happiness after a long and trying year. But have you ever stopped to wonder how much energy these lights consume?

A 2008 study from the US Energy Information Administration reported that decorative holiday lights in the United States accounted for 6.63 billion kilowatt-hours (kWh) of the country’s annual electricity consumption [1]. This equates to just 0.2% of total electricity consumption in the US. Even though this might be a small fraction of total electricity use, this alone exceeds the national electricity consumption in some developing countries, as shown in the figure below [1], [2].

Figure 1. A comparison of annual electricity consumption from decorative holiday lights in the US to the total electricity use in developing countries [2]. Original image can be found here.

Also note that the above plots only represent electricity use, which is only one aspect of overall energy use. Another big factor in increased winter demand is the use of natural gas and other fuels such as propane and furnace oil for space heating. Altogether, space heating accounts for over 61% of all residential energy use in Canada. Since much of the energy for space heating comes from gas and oil, it is not accounted for when looking at electricity use alone [5]. Figure 3 shows how Canadian residential natural gas consumption has more than quadrupled in the winter months compared to the summer months over the past 2.5 years, demonstrating the seasonal trend in demand.

In fact, 6.63 billion kWh of electricity is equal to the output of a 750 MW power plant or five hundred 1.5 MW wind turbines operating at full capacity over an entire year (where continual operation at full capacity is very unlikely for wind turbines due to the dependency on weather conditions), or, equivalently, the amount of electricity consumed by more than 620,000 US homes in one year (given the average annual household consumption of 10,649 kWh) [3].

More recently, the energy company Arcadia has estimated that electricity use for Christmas lights in the US for the month of December accounts for 3.5 billion kWh, which is just over half of the 2008 figure [3]. While the adoption of more energy-efficient LED lighting has greatly reduced energy consumption, this still accounts for a substantial amount of electricity and serves as a reminder to set your lights on timers if you haven’t done so already!

That said, numerous factors beyond holiday lighting increase energy demand in the winter. With the reduced daylight hours and colder weather, increased indoor activity drives an increase in energy demand for lighting and heating. This is shown in the monthly trends of average hourly electricity demands for different zones of Ontario in Figure 2 below. Note that seasonal demand is highly dependent on location and weather – in Southern Ontario (e.g. Toronto), the winter peak is comparable to summer peak electricity demand, primarily due to increased energy use for air conditioning in the hot summer months as well. However, in colder regions such as Northwestern Ontario, winter clearly represents the season of highest electricity demand.

Figure 2. A comparison of monthly trends in average hourly electricity demand in different zones of Ontario; Left: Toronto, Right: Northwest Ontario [4]. Original image can be found here.

Also note that the above plots only represent electricity use, which is only one aspect of overall energy use. Another big factor in increased winter demand is the use of natural gas and other fuels such as propane and furnace oil for space heating. Altogether, space heating accounts for over 61% of all residential energy use in Canada. Since much of the energy for space heating comes from gas and oil, it is not accounted for when looking at electricity use alone (e.g. Figure 2) [5]. Figure 3 shows how Canadian residential natural gas consumption has more than quadrupled in the winter months compared to the summer months over the past 2.5 years, demonstrating the seasonal trend in demand.

Figure 3. Monthly trends in Canadian residential natural gas consumption [6]. Original image can be found here.

It’s safe to say that our energy demand - looking at everything from heating to decorative lighting, from natural gas consumption to electricity use - increases in the winter months. So how can you do your part to reduce the strain these high demands put on our energy systems? Consider shifting your electricity and hot-water use outside of peak hours (6 a.m. to 9 a.m. and 4 p.m. to 8 p.m.) and lowering the thermostat when no one is in the room [7]. While we can’t change the weather, we can certainly change our habits to be more energy-wise. Now that would be something to be merry about!

References

[1] Navigant Consulting Inc., “Energy Savings Estimates of Light Emitting Diodes in Niche Lighting Applications,” Washington, 2008.

[2] T. Moss and P. Atansah, “US Holiday Lights Use More Electricity Than El Salvador Does In a Year | Center For Global Development,” 18-Dec-2015. [Online]. Available: https://www.cgdev.org/blog/us-holiday-lights-use-more-electricity-el-salvador-does-year. [Accessed: 22-Dec-2020].

[3] “The Energy To Light Christmas | Electricity News,” 20-Dec-2020. [Online]. Available: https://newselectricity.com/2020/12/20/the-energy-to-light-christmas/. [Accessed: 22-Dec-2020].

[4] IESO, “Hourly Zonal Demand Report.” [Online]. Available: http://reports.ieso.ca/public/DemandZonal/. [Accessed: 19-Sep-2020].

[5] “Heating equipment for residential use.” [Online]. Available: https://www.nrcan.gc.ca/energy-efficiency/energy-efficiency-products/product-information/heating-equipment-residential-use/13740. [Accessed: 23-Dec-2020].

[6] “Supply and disposition of natural gas, monthly (data in thousands).” [Online]. Available: https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=2510005501&pickMembers%5B0%5D=1.1&pickMembers%5B1%5D=3.1&cubeTimeFrame.startMonth=01&cubeTimeFrame.startYear=2016&cubeTimeFrame.endMonth=12&cubeTimeFrame.endYear=2020&referencePeriods=20160101%2C20201201. [Accessed: 23-Dec-2020].

[7] Hydro-Québec, “Being energy wise in cold weather.” [Online]. Available: https://www.hydroquebec.com/residential/customer-space/electricity-use/winter-electricity-consumption.html. [Accessed: 23-Dec-2020].

‘Tis the season…of higher energy demand!