| 2000 | 2018 | 2019 | 2020 | 2021 | ||
|---|---|---|---|---|---|---|
| Total Single Detached Heating System Stock (thousands) | 211.2 | 242.6 | 243.5 | 244.4 | 245.6 | |
Heating System Stock by Heating System Type (thousands) | ||||||
| Heating Oil – Normal Efficiency | 14.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 26.3 | 28.9 | 26.9 | 24.6 | 22.1 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 0.8 | 0.1 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 1.1 | 0.9 | 0.8 | 0.7 | 0.6 | |
| Natural Gas – High Efficiency | 1.3 | 5.8 | 6.1 | 6.5 | 6.9 | |
| Electric | 104.9 | 149.7 | 151.7 | 154.0 | 156.5 | |
| Heat Pump | 5.4 | 10.0 | 10.3 | 10.7 | 11.1 | |
| Other1 | 0.7 | 3.0 | 2.9 | 2.8 | 2.8 | |
| Wood | 9.6 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 32.3 | 30.0 | 30.2 | 30.4 | 30.8 | |
| Wood/Heating Oil | 13.4 | 12.3 | 12.4 | 12.5 | 12.7 | |
| Natural Gas/Electric | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil/Electric | 1.4 | 2.0 | 2.0 | 2.1 | 2.2 | |
Shares (%) | ||||||
| Heating Oil – Normal Efficiency | 6.6 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 12.5 | 11.9 | 11.1 | 10.1 | 9.0 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 0.5 | 0.4 | 0.3 | 0.3 | 0.2 | |
| Natural Gas – High Efficiency | 0.6 | 2.4 | 2.5 | 2.7 | 2.8 | |
| Electric | 49.6 | 61.7 | 62.3 | 63.0 | 63.7 | |
| Heat Pump | 2.6 | 4.1 | 4.2 | 4.4 | 4.5 | |
| Other1 | 0.3 | 1.2 | 1.2 | 1.2 | 1.1 | |
| Wood | 4.6 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 15.3 | 12.3 | 12.4 | 12.4 | 12.5 | |
| Wood/Heating Oil | 6.3 | 5.1 | 5.1 | 5.1 | 5.2 | |
| Natural Gas/Electric | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil/Electric | 0.7 | 0.8 | 0.8 | 0.9 | 0.9 | |