Energy Signature (PES)#
Goal
Display a Proposed Energy Signature (PES) with regression lines, following Eriksson et al. (2020). The PES relates the heating power of a building to the outdoor temperature while also considering the room temperature. Here the data is the electric power of a heat pump, so the regression describes the heat pump’s electricity demand (heat demand divided by its efficiency), not the heat demand itself.
Data Basis
The dataset bldgEngySigProposedData.csv contains hourly data with columns: time, outsideTemp, electricityHeatPump, roomTemp (separator ,). We build a 4-column DataFrame [timestamp, outside_temp, power, room_temp].
Data Preparation#
import pandas as pd
url = "https://raw.githubusercontent.com/retomarek/edap/main/edap/sampleData/bldgEngySigProposedData.csv"
raw = pd.read_csv(url, sep=",")
# Parse timestamp
raw["time"] = pd.to_datetime(raw["time"], utc=True).dt.tz_localize(None)
# Build 4-column DataFrame [timestamp, outside_temp, power, room_temp]
df = raw[["time", "outsideTemp", "electricityHeatPump", "roomTemp"]].copy()
df.columns = ["timestamp", "outside_temp", "power", "room_temp"]
df = df.dropna()
print(f"{len(df)} rows")
df.head()
11927 rows
| timestamp | outside_temp | power | room_temp | |
|---|---|---|---|---|
| 8212 | 2018-12-01 00:00:00 | 6.878333 | 7.143 | 23.300000 |
| 8213 | 2018-12-01 01:00:00 | 7.046667 | 0.159 | 23.300000 |
| 8214 | 2018-12-01 02:00:00 | 7.048333 | 0.159 | 23.300000 |
| 8215 | 2018-12-01 03:00:00 | 6.950000 | 0.160 | 23.300000 |
| 8216 | 2018-12-01 04:00:00 | 6.738333 | 0.159 | 23.266667 |
Visualization#
from pyedautils.plots import plot_energy_signature_pes
fig = plot_energy_signature_pes(df, title="Proposed Energy Signature (PES)")
fig.show()
Customization
The 4-column DataFrame must follow the column order [timestamp, outside_temp, power, room_temp]. With heat meter data instead of heat pump electricity, the same plot gives the building’s heat loss coefficient and balance temperature.
fig = plot_energy_signature_pes(df, title="Custom PES Title")
Reference: M. Eriksson, J. Akander, B. Moshfegh (2020): Development and validation of energy signature method – Case study on a multi-family building in Sweden before and after deep renovation. Energy and Buildings 210, 109756. doi:10.1016/j.enbuild.2020.109756