Solar PV calculator

Step 1: Access to the Calculator

• Open solar-calculation.com/en in your browser
• Click on the Solar Calculator button
• You will be automatically redirected to the calculation tool

Step 2: Enter Location Precisely

• Enter address: Enter your complete address or ZIP code in the white input field
• Search location: Click the blue Search Location button
• Check position: A map opens - verify that the displayed location is correct
• Confirm: Click Accept Position to continue

Step 3: Enter Basic System Data

Define power consumption:

• Enter your annual power consumption in kWh
• Orientation help: The reference values displayed on the left help with estimation
• Tip: Check your last electricity bill for exact values

Choose system size - two options:

Option A - Detailed input:

• Click Determine Solar Data and Continue
• Leads to comprehensive configuration (recommended for precise results)

Option B - Quick estimate:

• Select a predefined system size from the dropdown (S/M/L)
• Only inclination and orientation need to be adjusted
• Ideal for initial cost estimates

Step 4: Configure Solar System in Detail

4a) Basic Data Tab

• Name of solar surface: Assign a unique name (e.g., "South roof")
• Specify modules or area:
  • Either enter number of modules
  • Or enter available roof area in m² (automatically converted)
• Inclination angle: Roof pitch in degrees (optimal: 30-35° in Germany)
• Orientation: Set with slider (optimal: South = 180°)
• Save: Click Save or Save + Close

4b) Technology Tab (optional for experts)

• Solar modules: Specific performance data, efficiency, technology
• Inverter: Efficiency, maximum power, number of MPP trackers

4c) Shading Tab (important for accurate results)

• Add shading times: Click Add
• Select time period: Individual months or half-years
• Define times: From/to times of shading
• Shading degree: Percentage of shading (0% = none, 100% = complete)

Step 5: Advanced Configuration

5a) Storage Tab

• Enter storage capacity: Desired battery size in kWh
• Automatic calculation: Use Calculate Recommended Storage Size for optimal sizing
• Advanced parameters:
  • Battery type (Lithium-Ion, Lead-Acid)
  • Depth of discharge and efficiency
  • Lifespan and degradation
• Save changes: Don't forget to save

5b) Consumer Tab - Optimize Power Consumption

The calculator automatically created a basic consumer, you can add more:

General Consumer (Annual consumption):

• Assign name: e.g., "Household consumption"
• Usage times tab: Create individual daily profile
• Intensity curve: Set with slider for each hour of the day

Individual Consumer (specific devices):

• Add devices: e.g., heat pump, e-car charging, pool heating
• Define operating times:
  • Months: In which months is the device active?
  • Weekdays: On which days does it run?
  • Time intervals: Pre-made times (Morning, Midday, etc.)
  • Specific hours: Precise times from 0-24 hours

5c) Finance Tab - Calculate Profitability

Observation period:

• Recommended: 20-25 years (typical system lifespan)

Basic data:

• Electricity price: Current price per kWh (including basic fee converted)
• Electricity price increase: Annual increase in % (typical: 2-4%)
• Feed-in tariff: Current compensation rate according to EEG
• Operating costs: Annual maintenance and insurance (approx. 1-2% of acquisition)

Acquisition costs:

• Solar system: Complete system including installation
• Battery storage: Specify separately (if available)

Financing (optional):

• Direct purchase: Only enter equity capital, other fields remain deactivated
• Activate financing: Toggle switch for additional options:
  • Interest rate of financing
  • Term in years
  • Equity share

Use cost calculator:

• Click Open Cost Calculator for automatic cost estimation
• Installation type: On-roof, In-roof, or Ground-mount
• Installation: Professional or self-installation
• Additional components: Power optimizers, extended monitoring
• Apply results: Overwrite Costs or Add Costs

Start Calculation

• Click the blue Calculate button (top right)
• The calculation takes a few seconds
• You will be automatically redirected to the results page

Overview Tab - Key Figures at a Glance

• System power: Installed kWp and expected annual yield
• Self-consumption rate: What % of generated electricity is used by yourself
• Degree of autonomy: What % of electricity demand is covered by the solar system
• Payback time: After how many years the system has paid for itself
• Total yield: Yield over the entire lifespan

Finance Tab - Economic Efficiency in Detail

• Year selection: View different years with dropdown or slider
• Before/after comparison: Electricity costs with and without solar system
• Revenue breakdown:
  • Saved electricity costs through self-consumption
  • Income from grid feed-in
  • Tax advantages (if applicable)
• Cost breakdown:
  • Operating costs (maintenance, insurance)
  • Financing costs (with loan)
  • Depreciation
• Total balance: Cumulative balance since system start

Yield Tab - Detailed Analysis of Power Generation

Power Flow Overview:

• Generation vs. consumption: Total electricity quantities overview
• Usage diagram: How is the generated electricity used?
  • Direct self-consumption
  • Battery storage
  • Grid feed-in
• Autonomy diagram: Where does the consumed electricity come from?
  • Directly from the solar system
  • From battery storage
  • From the public grid

Temporal Breakdown:

• Monthly values: Seasonal variations recognizable
  • High yields in summer (May-August)
  • Lower yields in winter (November-February)
• Hourly profiles: Daily course of power generation
  • Peak around midday
  • Zero generation at night

Diagram Interaction:

• Click legend entries on/off to show/hide individual values
• This allows you to focus on specific aspects

Areas Tab - Analysis of Individual Roof Surfaces

• Area selection: View multiple roof surfaces individually
• Monthly yield: How much kWh does this specific surface generate?
• Hourly profile: Detailed generation distributed over the day
• Daily analysis: Select individual months for daily courses

For Realistic Calculations:

• Power consumption: Use annual statements from the last 2-3 years
• Don't forget shading: Even small obstacles can noticeably reduce yield
• Realistic price assumptions: Rather set conservative electricity price increases
• Plan operating costs: Approx. 1-2% of acquisition costs per year

For Different Scenarios:

• Vary system size: Test different numbers of modules
• Compare with/without storage: Is the battery economically viable?
• Optimize consumer timing: Schedule large consumers during sunny hours
• Financing vs. purchase: Calculate different financing options

Common Optimization Approaches:

• Maximize self-consumption: Run appliances like washing machine, dishwasher during the day
• Consider e-mobility: Plan e-car as additional consumer
• Integrate heat pump: Cover heating electricity through solar system
• Size storage correctly: Too small = missed opportunities, too large = uneconomical