As winter temperatures fluctuate, Massachusetts residents are keeping a close eye on their utility bills. According to EverSource spokesperson William Hinkle, a utility bill is best understood as three distinct “buckets,” each influenced by different economic and policy forces. Energy supplyThe largest and most unpredictable factor that goes into the bill is the energy supply. state Sen. William Brownsberger, policy-driven costs including Mass Save add 17.5% to 24% to electric bills and 12.3% to 39.1% to gas bills, depending on the customer type, season and utility territory. Average residential heating gas bill components in Massachusetts from the winter of 2014 and 2015 to the winter of 2024 and 2025.