2021 had the most heating required on record in 15 years

From summer wildfires to fall flooding, extreme weather events made 2021 a memorable and difficult year for many. The changing climate over the past 30 years also means significant impact on building energy use.

The chart below, updated to include 2021 data, shows how much variation there has been in Heating Degree Days (HDDs) each year since 2005, compared to a 30-year average.

HDDs are a key figure used for predicting building energy use and are directly calculated from the weather and a “balance point”, in this case 15 degrees Celsius. HDDs are a measure of how much heating energy is required over a period. The balance point is the temperature below which a building requires heating.

Remember the lack of snow on Cypress at the 2010 Olympics? You can see that the average HDDs that year was 9% less than the 30-year average, as reflected in the chart below.  In contrast, the 2021 calendar had 13% more HDDs than the 30-year average.

The most remarkable thing about this chart is how much it varies year to year. This variation is why PUMA uses weather data and built-in algorithms for utility use calculations.