Key Figures & Formulas: The Reference
Technical key figures are the language of energy technology. This overview explains all important parameters for solar systems and heat pumps.
Note: The articles are currently only available in German.
Solar System Key Figures
kW, kWh, kWp, efficiency, C-rate – what do these figures mean and how do they help with planning?
Read: Solar System Key Figures: The Glossary →Heat Pump Key Figures
COP, SPF, bivalence point – the most important key figures for planning and evaluation.
Read: Heat Pump Key Figures and Sizing →Quick Reference: The Most Important Units
Photovoltaics
| Unit | Name | Meaning |
|---|---|---|
| kW | Kilowatt | Power (work per time) |
| kWh | Kilowatt-hour | Energy (1 kW for 1 hour) |
| kWp | Kilowatt-Peak | Maximum PV power (STC) |
| % (η) | Efficiency | Usable / applied energy |
Battery Storage
| Unit | Name | Meaning |
|---|---|---|
| C | C-rate | Charge/discharge power / capacity |
| % DoD | Depth of Discharge | Maximum discharge depth |
| Cycles | Lifetime | Charge/discharge cycles to 80% capacity |
Heat Pumps
| Key Figure | Name | Meaning |
|---|---|---|
| COP | Coefficient of Performance | Momentary performance ratio |
| SPF | Seasonal Performance Factor | Year-round efficiency |
| SCOP | Seasonal COP | Normalized annual efficiency |