| 2000 | 2018 | 2019 | 2020 | 2021 | ||
|---|---|---|---|---|---|---|
| Total Single Detached Heating System Stock (thousands) | 302.3 | 354.3 | 356.6 | 358.8 | 361.2 | |
Heating System Stock by Heating System Type (thousands) | ||||||
| Heating Oil – Normal Efficiency | 1.4 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 4.3 | 2.6 | 2.1 | 1.6 | 1.2 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 83.9 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 49.4 | 44.6 | 40.3 | 36.3 | 32.4 | |
| Natural Gas – High Efficiency | 40.5 | 143.6 | 149.0 | 154.0 | 159.0 | |
| Electric | 89.7 | 126.5 | 127.6 | 128.7 | 129.7 | |
| Heat Pump | 7.0 | 14.0 | 14.4 | 14.8 | 15.2 | |
| Other1 | 2.9 | 1.4 | 1.4 | 1.3 | 1.3 | |
| Wood | 5.7 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 13.9 | 16.7 | 16.9 | 17.1 | 17.2 | |
| Wood/Heating Oil | 2.2 | 2.8 | 2.8 | 2.8 | 2.9 | |
| Natural Gas/Electric | 0.3 | 0.5 | 0.5 | 0.5 | 0.5 | |
| Heating Oil/Electric | 1.0 | 1.6 | 1.6 | 1.7 | 1.7 | |
Shares (%) | ||||||
| Heating Oil – Normal Efficiency | 0.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 1.4 | 0.7 | 0.6 | 0.5 | 0.3 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 27.7 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 16.3 | 12.6 | 11.3 | 10.1 | 9.0 | |
| Natural Gas – High Efficiency | 13.4 | 40.5 | 41.8 | 42.9 | 44.0 | |
| Electric | 29.7 | 35.7 | 35.8 | 35.9 | 35.9 | |
| Heat Pump | 2.3 | 3.9 | 4.0 | 4.1 | 4.2 | |
| Other1 | 1.0 | 0.4 | 0.4 | 0.4 | 0.4 | |
| Wood | 1.9 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 4.6 | 4.7 | 4.7 | 4.8 | 4.8 | |
| Wood/Heating Oil | 0.7 | 0.8 | 0.8 | 0.8 | 0.8 | |
| Natural Gas/Electric | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | |
| Heating Oil/Electric | 0.3 | 0.5 | 0.5 | 0.5 | 0.5 | |