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Solar Calculator: Consumption Data Scientifically Validated
Realistic self-consumption calculations require realistic consumption data. We have reviewed and adjusted our standard household profiles based on four scientific studies and current official statistics.
Why Does This Matter?
The self-consumption rate of a solar system depends significantly on the consumption profile. If consumption is overestimated, the calculated self-consumption rate becomes too optimistic. If underestimated, the economic viability is understated.
Our goal: Standard profiles that accurately represent typical German households.
Analysed Data Sources
We evaluated four scientific datasets compiled by the HTW Berlin:
1. ISFH Dataset (Lower Saxony)
| Property | Value |
|---|---|
| Households | 38 single-family homes |
| Measurement Period | 2018-2020 |
| Resolution | 10 seconds to 60 minutes |
| Focus | Heat pump households |
Source: Zenodo 5642902
2. Fresh Energy / TU Berlin
| Property | Value |
|---|---|
| Households | 200 households |
| Measurement Period | 01/2019 - 01/2020 |
| Resolution | 0.5 Hz (half-seconds!) |
| Special Feature | NILM device disaggregation |
Source: Zenodo 3855575
3. Open Power System Data (ISC Konstanz)
| Property | Value |
|---|---|
| Households | 6 residential buildings |
| Measurement Period | 12/2014 - 05/2019 (4.5 years) |
| Resolution | 1 minute to 60 minutes |
| Special Feature | Incl. PV, EV, heat pump |
Source: Open Power System Data
4. ECO Dataset (ETH Zurich)
| Property | Value |
|---|---|
| Households | 6 Swiss households |
| Measurement Period | 8 months |
| Resolution | 1 Hz + plug-level |
| Special Feature | Occupancy data |
Source: ETH Zurich
Comparison with Electricity Mirror 2024
Since the research datasets don't provide direct annual consumption by household size, we also compared our values with the Stromspiegel from co2online:
Single-Family Home (without electric water heating)
| Persons | Statistics 2024 | Calculator (old) | Calculator (new) | Difference |
|---|---|---|---|---|
| 1 | 1,800 kWh | 1,865 kWh | 1,865 kWh | +3.6% |
| 2 | 2,700 kWh | 2,525 kWh | 2,685 kWh | -0.6% |
| 3 | 3,500 kWh | 3,505 kWh | 3,505 kWh | +0.1% |
| 4 | 3,800 kWh | 4,385 kWh | 3,895 kWh | +2.5% |
| 5+ | 4,500 kWh | 5,485 kWh | 4,625 kWh | +2.8% |
Apartment (without electric water heating)
| Persons | Statistics 2024 | Calculator (old) | Calculator (new) | Difference |
|---|---|---|---|---|
| 1 | 1,200 kWh | 1,165 kWh | 1,165 kWh | -2.9% |
| 2 | 1,900 kWh | 1,745 kWh | 1,865 kWh | -1.8% |
| 3 | 2,400 kWh | 2,575 kWh | 2,575 kWh | +7.3% |
| 4 | 2,600 kWh | 3,275 kWh | 2,785 kWh | +7.1% |
| 5+ | 3,100 kWh | 4,155 kWh | 3,175 kWh | +2.4% |
What We Adjusted
The largest corrections affected larger households:
4-Person Households
- Gaming: Consumption reduced from 250 to 150 kWh (more realistic usage duration)
- Dryer: Reduced from 4x to 3x per week
- Cooking: Adjusted to typical household values
Large Families (5+ Persons)
- Computer/Gaming: Usage times and consumption reduced
- Washing Machine: Adjusted from 8x to 7x per week
- Second Refrigerator: Consumption slightly reduced
2-Person Households
- Dishwasher: Frequency increased (5x instead of 4x per week)
- Cooking: Slightly increased for more realistic total consumption
Conclusion
The standard profiles in the Solar Calculator now represent typical German households much more accurately. The maximum deviation from official statistics is now below 8% instead of up to 34% previously.
For you, this means: More precise self-consumption forecasts and more realistic economic calculations.
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