| 2000 | 2018 | 2019 | 2020 | 2021 | ||
|---|---|---|---|---|---|---|
| Total Single Detached Heating System Stock (thousands) | 255.9 | 290.7 | 292.1 | 293.6 | 295.3 | |
Heating System Stock by Heating System Type (thousands) | ||||||
| Heating Oil – Normal Efficiency | 55.1 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 71.4 | 83.2 | 82.7 | 80.3 | 79.7 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 0.4 | 0.1 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Medium Efficiency | 1.4 | 1.0 | 0.9 | 0.8 | 0.7 | |
| Natural Gas – High Efficiency | 1.6 | 5.9 | 6.3 | 6.8 | 7.1 | |
| Electric | 56.3 | 118.0 | 119.3 | 121.6 | 123.1 | |
| Heat Pump | 9.8 | 17.3 | 17.6 | 18.0 | 18.4 | |
| Other1 | 5.1 | 5.8 | 5.9 | 6.0 | 6.3 | |
| Wood | 1.4 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 21.9 | 24.2 | 24.2 | 24.4 | 24.5 | |
| Wood/Heating Oil | 30.4 | 33.5 | 33.5 | 33.8 | 33.9 | |
| Natural Gas/Electric | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil/Electric | 1.1 | 1.6 | 1.6 | 1.7 | 1.7 | |
Shares (%) | ||||||
| Heating Oil – Normal Efficiency | 21.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil – Medium Efficiency | 27.9 | 28.6 | 28.3 | 27.4 | 27.0 | |
| Heating Oil – High Efficiency | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Natural Gas – Normal Efficiency | 0.2 | 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 | 2.0 | 2.2 | 2.3 | 2.4 | |
| Electric | 22.0 | 40.6 | 40.9 | 41.4 | 41.7 | |
| Heat Pump | 3.8 | 6.0 | 6.0 | 6.1 | 6.2 | |
| Other1 | 2.0 | 2.0 | 2.0 | 2.1 | 2.1 | |
| Wood | 0.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
Dual Systems | ||||||
| Wood/Electric | 8.5 | 8.3 | 8.3 | 8.3 | 8.3 | |
| Wood/Heating Oil | 11.9 | 11.5 | 11.5 | 11.5 | 11.5 | |
| Natural Gas/Electric | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Heating Oil/Electric | 0.4 | 0.6 | 0.6 | 0.6 | 0.6 | |