The PV yield and profitability of a photovoltaic system result from a combination of technical, site-specific, and economic factors.
In short:
- The Yield describes how much electricity a plant produces
- The Economic efficiency depends on how this electricity is used or marketed
A reliable calculation can only be made with a individual analysis possible—especially for commercial systems. Rules of thumb such as “a PV system generates 800 to 1,200 kWh per year per installed kWp” or “east-west-facing roofs yield about 80–90% of the southern exposure yield” are unsuitable for this purpose. Especially for large systems in the megawatt range, even the slightest deviations can determine the profitability of the entire project.
What factors influence PV yield?
The actual electricity yield of a PV system is determined by several key factors:
1. Solar radiation (location)
- Most important influencing factor
- Depending on the region, weather, and annual cycle
- Basis of every earnings forecast
2. Module Alignment & Tilt Angle
- Classically optimal: South-facing
- Tilt angle for solar modules: 20–30°
- But not always economically optimal
Example:
- South-facing maximum yield at noon
- East-west orientation → consistent yield throughout the day
For companies, east-west orientation is often more sensible, as the yield is better matched to consumption.
3. Company Profile
- Crucial for economic viability
- High daily consumption = high self-consumption = better return
Therefore, the best investment is not the one with the highest return, but the one with the highest self-consumption.
4. Shading & Environment
- Buildings, trees, superstructures (e.g., chimneys) or high-voltage pylons and lines
- Even small shadings can cause large yield losses
5. Temperature & Environmental Conditions
- High temperatures reduce efficiency
- Dust, dirt, or industrial emissions reduce the yield
6. Components of the PV System
- Efficiency of the solar cells or module quality (e.g., monocrystalline vs. other technologies)
- Inverter oversizing factor
- Cabling (Lengths, Losses)
Errors in planning can lead to runtime issues five-figure revenue losses cause.
7. Operation & Maintenance
- Regular Maintenance of PV systems secures the yield
- Errors or performance losses are detected early
- Photovoltaic cleaning boosts profitability and efficiency
Why is economic efficiency more important than pure PV yield?
A high PV yield does not automatically mean high profitability. What is decisive is:
- When the electricity is generated
- How it is used
- At what price it is being evaluated
Example:
- Feed-in → low compensation
- Self-consumption → high savings
Therefore, the following applies: Self-consumption is the most important lever for economic efficiency.
What factors determine the economic viability of a PV system?
Besides the PV yield, other economic factors play a role:
- Electricity price (current and future)
- Self-consumption rate
- Investment costs
- Operating costs
- Funding and regulatory frameworks
- Asset lifetime (typical: 20+ years)
Why aren't online calculators sufficient for businesses?
Standardized PV calculators are usually unsuitable for commercial installations because they:
- do not consider individual load profiles
- Roughly capture shading
- Do not depict complex electricity price structures
- ignore regulatory factors
For companies, even the smallest deviations can lead to massive economic miscalculations lead.
How is a realistic PV economic feasibility study created?
A well-founded calculation includes several steps:
1. location analysis
- Irradiation
- Roof/Area inspection
- Shading
2. Consequence Analysis
- Electricity consumption over time
- Identification of optimization potential
3. System Planning
- System Sizing
- Alignment and Technique
4. Economic feasibility model
- Investment costs
- Electricity price assumptions
- Self-consumption and feed-in
5. Scenario Evaluation
- Best Case / Worst Case
- Sensitivity analyses (e.g., electricity prices)
What common mistakes should companies avoid?
- Focus only on maximum yield instead of profitability
- Incorrect system sizing
- Neglect of the load profile
- insufficient consideration of shading
- missing energy management
Conclusion: PV yield is predictable – economic viability is crucial
The PV yield is the technical basis – profitability only arises from proper planning and utilization.
For companies, this means:
- Individual planning instead of standard solutions
- Focus on self-consumption and load optimization
- holistic view of technology and economics
Only this way can photovoltaic systems be operated optimally and used economically in the long term.