During the dark and cooler days of winter time, energy bills tend to go up, which has home and business owners taking more notice. Many of you reached out to News19 about why Dominion Energy bills were so high this month. Dominion Energy tells us this winter required more heating because of the weather.
Weather related heating needs last winter were the 9th lowest on record for South Carolina (going back to 1888). NOAA tracks heating needs using heating degree days, which calculates the "coolness" of each day by taking the daily high and low temperature and subtracting the average by 65 for each day of the winter.
Overall heating needs are higher this winter than last winter, but autumn 2020 required less heating than autumn 2019. The heating requirements in both October and November 2020 were lower than in 2019 and lower than the climatological average, but more heating was required this past December. December 2020 heating needs were higher than the 30-year climatological average. This could explain an increase in energy bills that month. The weather in January 2021 has also been cooler last January, but the need for heat in January 2021 is still lower than the 30-year climatological average for the month (as of January 28).
Heating degree days are an effective way to get a general idea of energy requirements due to the weather, but there are limitations with this method. Heating degree days do not take into account how long cool temperatures last through the day. During a day where the high temperature happens at midnight and temperatures cool down in the afternoon, the heating degree day numbers will underestimate how cool the day really was. Heating degree days do not take the energy required to power lights or other appliances into account. Energy usage this season may also be higher than past years because of extra time spent at home due to the Global Health Crisis.
