| 2000 | 2018 | 2019 | 2020 | 2021 | ||
|---|---|---|---|---|---|---|
| Total Single Detached Heating System Stock (thousands) | 293.9 | 342.3 | 343.4 | 344.4 | 345.8 | |
Heating System Stock by Heating System Type (thousands) | ||||||
| Heating Oil – Normal Efficiency | 4.1 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 6.0 | 6.4 | 5.9 | 5.2 | 4.4 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 139.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 63.7 | 74.8 | 69.4 | 64.1 | 58.9 | |
| Natural Gas – High Efficiency | 48.9 | 197.8 | 202.9 | 207.9 | 213.4 | |
| Electric | 8.0 | 36.3 | 37.9 | 39.6 | 41.2 | |
| Heat Pump | 6.6 | 13.1 | 13.5 | 13.8 | 14.1 | |
| Other1 | 5.0 | 4.3 | 4.2 | 4.2 | 4.2 | |
| Wood | 4.1 | 0.2 | 0.1 | 0.1 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 2.5 | 2.3 | 2.3 | 2.3 | 2.3 | |
| Wood/Heating Oil | 3.6 | 3.3 | 3.3 | 3.3 | 3.3 | |
| Natural Gas/Electric | 1.4 | 2.1 | 2.2 | 2.2 | 2.2 | |
| Heating Oil/Electric | 1.1 | 1.7 | 1.7 | 1.7 | 1.8 | |
Shares (%) | ||||||
| Heating Oil – Normal Efficiency | 1.4 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 2.0 | 1.9 | 1.7 | 1.5 | 1.3 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 47.3 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 21.7 | 21.9 | 20.2 | 18.6 | 17.0 | |
| Natural Gas – High Efficiency | 16.6 | 57.8 | 59.1 | 60.4 | 61.7 | |
| Electric | 2.7 | 10.6 | 11.0 | 11.5 | 11.9 | |
| Heat Pump | 2.3 | 3.8 | 3.9 | 4.0 | 4.1 | |
| Other1 | 1.7 | 1.2 | 1.2 | 1.2 | 1.2 | |
| Wood | 1.4 | 0.1 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | |
| Wood/Heating Oil | 1.2 | 1.0 | 1.0 | 1.0 | 0.9 | |
| Natural Gas/Electric | 0.5 | 0.6 | 0.6 | 0.6 | 0.7 | |
| Heating Oil/Electric | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | |