Figure 1
Example of power signature for a single-family house.
Figure 2
Comparison of power signatures for three different data resolutions: hourly mean(left), daily mean (middle) and weekly mean (right).
Table 1
Estimated energy for heating with power signature and energy use for domestic hot water and domestic electricity.
| HOUSE NO: | HEATING SYSTEM | ENERGY CLASS1 | HEAT LOSS FACTOR (W/°C) | BALANCE TEMPERATURE (°C) | R2-VALUE | ENERGY FOR HEATING (kWh/YEAR) | ENERGY FOR DOMESTIC HOT WATER (DHW) AND DOMESTIC ELECTRICITY (DE) (kWh/YEAR) |
|---|---|---|---|---|---|---|---|
| 1 | Air-water heat pump | 268 | 12 | 0.86 | 10,238 | 9,173 | |
| 2 | Air-water heat pump2 | C | 240 | 14 | 0.76 | 12,256 | 3,060 |
| 3 | District heating | 94 | 14 | 0.71 | 4,656 | DHW: 4,822 | |
| Electricity | 54 | 22 | 0.61 | 5,987 | DE: 7,486 | ||
| 4 | District heating | 517 | 16.5 | 0.82 | 33,801 | DHW: 3,579 | |
| Electricity | –2 | 0.1 | DE: 3,990 | ||||
| 5 | Exhaust air heat pump | D | 141 | 11.5 | 0.68 | 5,255 | 7,043 |
| 6 | Exhaust air heat pump | B | 121 | 9 | 0.84 | 3,054 | 4,175 |
| 7 | Direct electric heating | F | 236 | 14.8 | 0.77 | 13,212 | 5,423 |
| 8 | Exhaust air heat pump2 | B | 62 | 14 | 0.27 | 3,150 | 6,458 |
| 9 | Air-water heat pump2 | 119 | 13 | 0.82 | 5,400 | 4,046 | |
| 10 | Ground source heat pump, Passive house2 | A | 52 | 11 | 0.17 | 1,559 | 5,584 |
| 11 | Electric boiler, year 2020 | E | 184 | 15 | 0.78 | 8,562 | 6,811 |
| Electric boiler, new windows, year 2021 | 130 | 15 | 0.75 | 7,575 | 10,517 | ||
| Air-water heat pump, year 2024 | 70 | 13 | 0.76 | 2,804 | 3,241 |
[i] 1For those houses where an existing Energy Performance Certificates is available.
2PV-system is available. Self-produced solar power not included in the power signature.
Figure 3
Power signature for building 11, year 2020 (left), after replacement of windows (centre, 2021) and after installation of air-water heat pump and mechanical exhaust ventilation (right, 2024).
Table 2
Energy for heating for Houses 2, 5 and 6 based on the current method and the power signature method.
| HOUSE | ELECTRICITY FOR HEATING | DOMESTIC ELECTRICITY AND ELECTRICITY FOR DOMESTIC HOT WATER | ||
|---|---|---|---|---|
| CURRENT METHOD (kWh/YEAR) | POWER SIGNATURE METHOD (kWh/YEAR) | CURRENT METHOD (kWh/YEAR) | POWER SIGNATURE METHOD (kWh/YEAR) | |
| 2 | 7,022 | 12,256 | 7,098 + 1,076 = 8,174 | 3,060 |
| 5 | 2,605 | 4,285 | 4,330 + 3,500*+ 1,348 = 9,178 | 8,153 |
| 6 | 3,042 | 3,054 | 2,634 + 1,132 = 3,766 | 4,175 |
[i] *Electricity for electric car.