PV Yield per kWp in 2026: How Many kWh Are Realistic?
In 2026, a solar power system in Germany will generate, on a long-term average, approximately 900–1,100 kWh per installed kilowatt-peak per year. This specific yield is the most important metric for comparing systems of different sizes and locations—and forms the basis of any economic feasibility analysis.
The short answer
A professionally installed PV system in Germany will generate approximately 1,000 kWh per kWp per year on a long-term average in 2026—with a range from about 900 kWh/kWp in northern Germany to 1,150 kWh/kWp in southern Germany. In its “Current Facts on Photovoltaics in Germany,” the Fraunhofer ISE cites a reference value of approximately 980–1,000 kWh/kWp for an average location. 2025 was an above-average year, with 1,187 kWh/m² of global radiation and over 1,945 hours of sunshine—many systems performed at the upper end of the range. Modern TOPCon and HJT modules now lose only 0.3–0.4% of their output per year; the performance ratio of high-quality systems ranges from 80–87%. Over 25 years, the total yield amounts to approximately 23,000 kWh per kWp. For a reliable profitability analysis, you should base your calculations on the long-term average of approximately 1,000 kWh/kWp, not on the peak values from 2025.
How many kWh per kWp will a photovoltaic system actually generate in 2026? The specific PV yield is the key metric for comparing systems of different sizes and locations. This article explains how this value is determined by solar irradiance, the performance ratio, and module degradation; highlights regional differences between southern and northern Germany; and details how much electricity a 5-, 10-, 30-, or 100-kWp system actually produces. It is aimed at businesses with their own rooftop space and at investors in direct PV investments, for whom the specific yield forms the basis of every revenue forecast.
1. What does "specific yield" mean?
Three terms are often confused in practice, but they should be clearly distinguished:
Rated power (kWp – kilowatt-peak): The maximum power output of the modules under standardized test conditions (1,000 W/m² irradiance, 25 °C module temperature, AM 1.5 spectrum). This is purely a laboratory figure, not the operating point on a German roof. Watt-peak (Wp) is the smaller unit; 1 kWp = 1,000 Wp.
Output (kWh): The amount of electrical energy actually generated over a given period (day, month, year), also known as electricity output.
Specific annual yield (kWh/kWp per year): Annual yield divided by rated power. An 8-kWp system in Munich with a yield of 9,200 kWh has the same specific yield (1,150 kWh/kWp) as an 80-kWp system at the same location with a yield of 92,000 kWh—hence the comparability.
Convert kWp to kWh
The calculation: Annual yield (kWh) = rated power (kWp) × specific yield (kWh/kWp). Conversely, specific yield = annual yield ÷ rated power. To convert kWp to kWh, multiply the rated power by the specific yield typical for the location. On average across all locations and years in Germany, the specific yield is around 1,000 kWh/kWp—a value that has appeared for years as a reference in the Fraunhofer ISE’s “Current Facts on Photovoltaics in Germany” and is confirmed in the EU database PVGIS.
2. Current Figures for 2025/2026: Global Radiation, Sunshine Hours, PV Generation
| Key figure | Value | Classification |
|---|---|---|
| Global Radiation in Germany in 2025 | 1,187 kWh/m² | Above average, approximately +9% above the 1991–2020 average (DWD) |
| Sunshine Duration in 2025 | over 1,945 hours | One of the top 5 years since 1951 (DWD) |
| Gross PV Generation in 2025 | about 87 TWh | +21% compared to 2024 (Fraunhofer ISE) |
| Installed PV capacity by the end of 2025 | 116.8 GWp DC | EEG Expansion Target Achieved (Fraunhofer ISE / MaStR) |
| Installed PV Capacity as of the End of May 2026 | 118.2 GWp | continuing to rise (BSW Solar) |
| PV Grid Feed-in H1 2026 | 43.2 TWh | +10% compared to the previous year, a half-year record (Fraunhofer ISE) |
| Share of Solar Power in Net Electricity Generation, H1 2026 | 18,2 % | +1.3 percentage points (Fraunhofer ISE) |
| Sources: DWD press release “Weather in Germany in 2025” (December 30, 2025) · Fraunhofer ISE / Energy-Charts · Federal Network Agency Market Master Data Register. | ||
Important Note: 2025 was an exceptional year. For a reliable economic analysis spanning 20 or 30 years, you should not base your calculations on the peak values from 2025, but rather on the long-term average of approximately 1,000 kWh/kWp at a typical location.
A quick note on terminology: Sun hours are not the same as full-load hours. The 1,945 hours of sunshine in 2025 refer to the time during which the sun shone unfiltered. The full-load hours of a system—the time during which it theoretically generates power at its rated output—amount to around 1,000 hours per year, because diffuse light also generates electricity, but the module output rarely reaches 100%.
3. How many kWh per kWp in your region?
Global radiation—the total amount of solar energy per square meter—is not distributed evenly across Germany. In terms of climate, southern Germany receives 1,150–1,300 kWh/m² of annual solar radiation, while northern Germany receives 950–1,080 kWh/m². The following PV yield table lists the specific yield for ten locations based on the EU database PVGIS-SARAH2 (15-year average, south-facing orientation, 30° tilt, 14% system losses).
| City / Region | State | Total solar radiation (kWh/m²) | Specific Yield (kWh/kWp) |
|---|---|---|---|
| Freiburg | Baden-Württemberg | 1,250–1,300 | 1,100–1,160 |
| Munich | Bavaria | 1,180–1,230 | 1,080–1,130 |
| Stuttgart | Baden-Württemberg | 1,150–1,200 | 1,050–1,100 |
| Nuremberg | Bavaria | 1,130–1,180 | 1,030–1,080 |
| Frankfurt | Hesse | 1,100–1,150 | 1,020–1,070 |
| Berlin / Potsdam | Berlin / Brandenburg | 1,060–1,110 | 1,000–1,055 |
| Cologne | North Rhine-Westphalia | 1,030–1,080 | 970–1,020 |
| Hanover | Lower Saxony | 1,000–1,050 | 950–990 |
| Hamburg | Hamburg | 970–1,020 | 920–970 |
| Kiel | Schleswig-Holstein | 950–1,000 | 900–950 |
| Calculation performed using PVGIS Version 5.2, PVGIS-SARAH2 database. Assumptions: monocrystalline modules, 14% system losses (inverter, cabling, soiling, mismatch, temperature). Actual yields vary by ±10–15% from year to year. | |||
The difference in solar output may seem small—but for a 10-kWp system, there’s a difference of about 2,000 kWh per year between Freiburg and Hamburg. Over 20 years, that adds up to 40,000 kWh; at a commercial electricity rate of 25 ct/kWh, that amounts to a difference of about €10,000 due solely to the location.
4. PV Output Over the Course of the Year: The Monthly Trend
Seasonal distribution is critical to economic efficiency. If a business has a consistent electricity demand throughout the year, but the system produces a surplus in the summer and does not supply enough in the winter, this affects the self-consumption rate and the storage system design.
| Month | Share of annual revenue | kWh/kWp (at 1,000 kWh/kWp per year) |
|---|---|---|
| January | 2–3% | 20–30 |
| February | 4–5% | 40–50 |
| March | 8–9% | 80–95 |
| April | 11–12% | 110–125 |
| May | 13–15% | 130–150 |
| June | 13–15% | 130–155 |
| July | 13–14% | 125–145 |
| August | 12–13% | 115–135 |
| September | 9–10% | 90–105 |
| October | 6–7% | 55–70 |
| November | 3–4% | 25–35 |
| December | 2–3% | 17–30 |
| Summer half-year (April–September): approximately 70% of annual output. Four months (May–August): approximately 50–55%. Source: PVGIS-SARAH2 and Fraunhofer ISE Energy Charts (monthly balances for 2020–2025). With optimized east-west mounting, the curve may be flatter. | ||
This distribution is relevant for two decisions: storage sizing—those who want to be more independent of the grid in winter need disproportionately large storage systems—and the self-consumption rate—businesses with consumption concentrated in the summer (air conditioning, cold storage, irrigation) benefit disproportionately. The article “PV with Battery Storage: Self-Consumption and Cost-Effectiveness in 2026” explores the economic viability of storage in greater depth.
5. How much electricity does a 10-kWp system generate? Sample calculations for 5 to 100 kWp
| Appendix | Annual yield (average) | North–South Bandwidth | Ø Day Summer | Ø Day Winter |
|---|---|---|---|---|
| 5 kWp | 5,000 kWh | 4,500–5,750 kWh | 18–25 kWh | 3–6 kWh |
| 10 kWp | 10,000 kWh | 9,000–11,500 kWh | 35–50 kWh | 5–10 kWh |
| 30 kWp small commercial system | 30,000 kWh | 27,000–34,500 kWh | 105–150 kWh | 15–30 kWh |
| 100 kWp commercial/industrial roof | 100,000 kWh | 90,000–115,000 kWh | 350–500 kWh | 50–100 kWh |
| The range is due to regional differences in global radiation. Daily values are monthly averages—a sunny day in June can yield as much as 60 kWh from a 10-kWp system, while an overcast day in December yields only 1–2 kWh. Our own calculation based on data from Fraunhofer ISE and PVGIS. | ||||
Energy Output of a 10-kWp Photovoltaic System
Calculation using the example of 10 kWp: Annual yield = 10 kWp × 1,000 kWh/kWp = 10,000 kWh. During the summer months (about 70%), this amounts to 7,000 kWh over 183 days, or about 38 kWh per day; during the winter months, it’s about 16 kWh per day.
This linearity also applies to direct investments: Anyone investing in a 1-MW ground-mounted system (1,000 kWp) can expect an annual yield of approximately 1,000,000 kWh. Scaling up works precisely even into the double-digit megawatt range because the specific yield is independent of the system size.
What level of yield is realistic for your location?
Logic Energy designs, builds, and operates turnkey PV systems for businesses and investors—using conservative yield assumptions, calibrated modules, and a documented performance ratio. The contractual partner for direct investments is mediplan Helm e.K., with personal liability on the part of the owners.
Plan Your Own Solar Power SystemInvest as a Capital Investor
6. What Affects PV Output? Nine Factors
| factor | Typical effect | Note |
|---|---|---|
| Location (global radiation) | ±15–20% | South vs. North |
| Alignment and Tilt | −5% to −30% | South 30° = 100%, East-West 10° = 92%, North 30° = 70% |
| Shading (in certain areas) | −5% to −20% | In a string inverter, the weakest module determines the string |
| Soiling | −2 to −5% per year | Self-cleaning by rain at slopes of 15° or greater; in agricultural settings, up to −12% |
| Module temperature (60 °C in summer) | −10% to −12% | Temperature coefficient: PERC −0.35%/°C, TOPCon −0.30%/°C, HJT −0.25%/°C |
| Module Efficiency in 2026 | 19–26% | PERC 19–21%, TOPCon 22–23.5%, HJT 24–26% |
| Inverter Efficiency | 96–98.4% | Premium appliances with over 98% Euro efficiency |
| Cabling and Mismatch | −2% to −4% | DC cable 1–2%, mismatch 1–2% |
| Module Under-Performance Compared to Datasheet | −1.2% on average | Fraunhofer ISE CalLab 2024: 1,034 modules measured |
| Sources: Fraunhofer ISE, PVGIS, manufacturer data sheets as of 2025/26. | ||
Roof orientation, pitch, and module area
Orientation and tilt angle are key factors in determining the energy yield per square meter of module area. A south-facing orientation yields the highest output; in Germany, the optimal tilt angle is around 30–35 degrees. A north-facing roof surface significantly reduces output—to about 70% of the south-facing value at a 30° tilt. High-quality monocrystalline modules convert sunlight more efficiently than older polycrystalline types, and cool, sunny days are particularly productive due to the temperature coefficient. Shading from trees or neighboring buildings, on the other hand, can greatly reduce electricity output.
Module Power Derating Compared to the Datasheet
A survey conducted by Fraunhofer ISE CalLab in 2024 found that the actual power output of 1,034 monocrystalline modules was, on average, 1.2% below the manufacturers’ specifications. Prior to 2017, the deviation was neutral. For system planning, this means factoring in a 1–2% safety margin.
Pollution
In Germany, annual losses due to soiling (dust, pollen, bird droppings, Saharan dust) typically range from 2–5%. In agricultural areas with ammonia pollution, losses can reach up to 12%. Modules with an inclination of less than 15° become dirtier more quickly because rain is less effective at cleaning them.
Module Temperature
Modules are calibrated at 25 °C, but their surface temperature can reach 50–70 °C in the summer. At 65 °C, a PERC module loses about 14% of its power output compared to standard conditions, while a modern HJT module loses only about 10%. In midsummer, HJT technology therefore delivers 2–4% higher yield for the same rated power—a factor that is particularly relevant for ground-mounted systems in southern Germany.
7. Performance Ratio: Your Investment's Quality Metric
The PR highlights the difference between weather conditions and system quality. Two systems at the same location should produce similar yields in the same year. If they do not, the specific yield alone does not indicate the cause. The PR is calculated by dividing the actual yield by the theoretically possible yield based on measured irradiance.
Calculation: PR = Actual yield (kWh) ÷ [Rated power (kWp) × Global radiation at the module level (kWh/m²) ÷ 1 kW/m²]. Example: A 10-kWp system receives 1,100 kWh/m² at the module level and generates 9,000 kWh per year. PR = 9,000 ÷ (10 × 1,100) = 0.818, or 81.8%—a typically good value.
| Public Relations | Rating | A typical situation |
|---|---|---|
| over 85% | excellent | Professional ground-mounted system, new modules, optimal location |
| 80–85% | Very good, industry standard | Well-designed rooftop system, modern inverter |
| 75–80% | acceptable | suboptimal orientation or slight shading |
| less than 75% | Room for improvement | Shading, dirt, broken strings – Check the system |
| Source: Fraunhofer ISE. The improvement from around 70% before 2000 to 80–87% today is due to higher module efficiencies, better MPP trackers, more efficient inverters, and glass-glass modules with lower mismatch. | ||
For investors, the PR is relevant for two reasons: First, it determines the revenue forecast—an improvement in PR from 78% to 84% corresponds to approximately an 8% increase in revenue. Second, it serves as an objective quality criterion: A system with a documented PR above 84% after three years of operation demonstrates sound design and effective monitoring. The article on inverter revenue sharing illustrates how measured generation can be directly linked to investor returns.
8. Degradation: What remains of the yield after 25 years?
Degradation is the most gradual, yet mathematically decisive factor in life-cycle costs. Unlike weather-related annual fluctuations (±10–15%), it is a monotonous and irreversible process.
| Technology | Mainstream 2026 | Premium | Discontinued |
|---|---|---|---|
| Name | TOPCon (n-type) | HJT (Heterojunction) | PERC (p-type) |
| Module efficiency | 22–23.5% | 24–26% | 19–21% |
| Temperature Coefficient Pmax | −0.29 to −0.32 %/°C | −0.24 to −0.26 %/°C | −0.34 to −0.35%/°C |
| Annual demotion | 0.3–0.4% | 0.25–0.30% | about 0.5% |
| Typical Performance Guarantee | 25 years (linear), approximately 85% | 30 years (linear), approximately 87% | 25 years linear, 80–84% |
| Sources: Fraunhofer ISE Photovoltaics Report · ITRPV Roadmap · NREL (Jordan/Kurtz) · Manufacturer data sheets 2026. TOPCon surpassed PERC as the global market leader for the first time in 2024. | |||
A 25-year projection with 0.5% linear degradation and an initial value of 1,000 kWh/kWp illustrates the order of magnitude: In year 25, the system still delivers about 880 kWh/kWp; cumulatively, that amounts to about 23,000 kWh per kWp. For TOPCon with 0.4% degradation, the cumulative 25-year generation is about 1.5% higher; for HJT with 0.30% degradation, it is about 3% higher.
For direct investments with a term of 20 to 40 years, degradation is the main reason why revenue forecasts decline over time. In year 25, a system generates about 12% less electricity than in year 1—but this is usually offset by stable or rising electricity prices. For businesses with their own rooftop systems, degradation means that the self-consumption rate tends to rise over the years as electricity demand increases.
9. Theory vs. Reality: Putting Vendor Promises into Perspective
Four recurring sources of discrepancies between forecasts and reality: First, optimistic loss assumptions—quotes often assume 8–10% system losses, while PVGIS uses a more realistic estimate of 14%. Second, data sheet optimism—the Fraunhofer CalLab study showed a 1.2% reduction in output. Third, shading underestimated during on-site visits—a loss of 2–5% for each overlooked shadow cast. Fourth, weather variability—in 2024, the average PV yield in Germany was significantly lower than in the peak year of 2025.
For reliable profitability calculations, it is recommended to use long-term averages: approximately 950 kWh/kWp for central Germany, 1,050 for southern Germany, and 900 for northern Germany. If a provider uses significantly higher values in their calculations, you should ask about the underlying loss assumptions and the data source—PVGIS-SARAH2 or Meteonorm are reliable sources. For investors, the following also applies: A revenue forecast that does not distinguish between the high-yielding first years of operation and the later years, when degradation sets in, is methodologically flawed.
10. Outlook: What Does 2026 Hold for New Installations?
Three trends are emerging for 2026. First, module efficiencies continue to rise: mainstream TOPCon modules are reaching 22–24%, and the first perovskite-silicon tandem modules are on the market with efficiencies exceeding 24%, though widespread adoption is not expected until 2027/28. Second, new installations are shifting toward large-scale systems: In the residential segment, new installations declined in 2025, while ground-mounted and large-scale rooftop systems are growing—see the article on photovoltaic expansion in Germany for details. Third, following the peak year of 2025, a return to the long-term average is statistically likely—anyone calculating a new system in 2026 based on 2025 figures will systematically overestimate the yield. A conservative estimate of around 1,000 kWh/kWp remains the most reliable basis.
Frequently Asked Questions (FAQ)
How many kWh does a 10-kWp system produce per year?
A 10-kWp system in Germany generates an average of about 10,000 kWh per year over the long term. In southern Germany, the figure is 11,000–11,500 kWh, while in the north it is closer to 9,000–9,500 kWh. For a south-facing system with a 30° tilt and no shading, the specific yield is approximately 1,000 kWh/kWp.
What is considered a good yield per unit area in Germany?
A specific yield of 950–1,050 kWh/kWp per year is considered a good figure for central Germany. In southern Germany, yields of 1,050–1,150 kWh/kWp are possible, while in the north, yields range from 900 to 970 kWh/kWp. Values below 850 kWh/kWp are a warning sign of problems with orientation, shading, or the system itself.
What is the performance ratio of a solar power system?
The performance ratio measures how much of the theoretically possible energy a system actually delivers, and isolates the system's performance from the effects of weather. Modern systems achieve 80–87%; before the year 2000, the typical value was around 70%. Values below 75% indicate a need for optimization.
How much do modern solar panels degrade over time?
Current TOPCon modules lose about 0.3–0.4% of their power output per year, while premium HJT modules lose only 0.25–0.30%. After 25 years, they retain 84–88% of their initial power output. The NREL meta-study reports a median of 0.5% per year for crystalline modules. Manufacturers now offer linear warranties covering 25 to 30 years.
How much of the annual yield is produced during the winter months?
About 30% of the annual yield is produced between October and March, with the remaining 70% coming during the summer months of April through September. December accounts for only 2–3% of the annual yield, while June accounts for 13–15%. The ratio of June to December is about 7:1.
Was 2025 a typical year for PV output?
No. With 1,187 kWh/m² of global radiation, 2025 was one of the years with the highest levels of radiation since records began in 1983, and with over 1,945 hours of sunshine, it was one of the five sunniest years since 1951. When performing economic feasibility calculations, you should not base your estimates on the peak values from 2025, but rather on the long-term average of approximately 1,000 kWh/kWp.
How much electricity does a 100-kWp commercial solar system generate?
A 100-kWp system generates approximately 100,000 kWh per year in Germany, ranging from 90,000 kWh in the north to 115,000 kWh in southern Germany. The specific yield is independent of the system size; therefore, the yield scales linearly with the installed capacity.
Conclusion
The specific yield is the key metric in any PV profitability analysis—for businesses with their own roof space as well as for investors in direct investments. Realistic figures in Germany range from about 900 to 1,100 kWh/kWp per year, with an average of approximately 1,000 kWh/kWp. It is crucial to base calculations on the long-term average rather than the peak values projected for 2025, to use the performance ratio as a quality criterion, and to factor in degradation over the entire system lifetime.
If you’re planning to install your own system, you’ll find information on the investment and payback logic under “Your Own PV System for Your Business.” If you’d like to invest without owning a roof, you’ll find details on the return structure and tax benefits on the “Photovoltaic Investment” overview page; the article on “Inverter Revenue Sharing” explains how investor returns are linked to metered generation.
References
- Fraunhofer ISE – Current Facts on Photovoltaics in Germany (as of 2026): Specific Yield in Central Germany, Performance Ratio Trends, System Metrics
- Fraunhofer ISE – Photovoltaics Report: Module Efficiency, Degradation Rates, Market Shares of TOPCon/HJT/PERC
- Fraunhofer ISE / Energy Charts: PV Generation, Share of the Electricity Mix, Monthly Balances, H1 2026 Analysis
- Fraunhofer ISE – Actual Solar Module Performance Often Overstated (Press Release, March 12, 2025): CalLab Measures 1,034 Modules, Performance Shortfall of 1.2%
- NREL / DOE OSTI – Photovoltaic Degradation Rates, an Analytical Review (Jordan/Kurtz, NREL/JA-5200-51664): Median degradation of 0.5% per year
- German Weather Service – Weather in Germany in 2025 (Dec. 30, 2025): Sunshine duration 1,945 h, global radiation 1,187 kWh/m²
- PVGIS – Photovoltaic Geographical Information System (EU JRC): PVGIS-SARAH2 database for regional yields and monthly distribution
- Federal Network Agency – Market Master Data Registry: Installed PV Capacity, Monthly Additions
- BSW Solar – German Solar Industry Association: Industry Statistics, Installed Capacity, Segment Growth
- ITRPV – International Technology Roadmap for Photovoltaics: Cell Technology Market Shares, n-Type Wafer Share
Edited by Logic Energy. Last updated: August 2026.
