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Price of the solar electric system
Please consider: For the calculation of price, size and yield of the planned PV system standard modules (nominal power: 275 Wp, dimensions: 1665 mm x 991 mm) are preset.
The selection of certain module types with different dimensions, prices or efficiencies may lead to different results.
For an accurate calculation, a local appointment as well as a system calculation and dimensioning by a specialist is necessary.
With appropriate consideration, the value-added tax could be refunded by the finance office. For this, please consult a tax expert.
Barred areas
For example barred areas are windows, dormers, chimneys.
This parameter has a direct influence on the calculation of the system`s size.
In order to determine the accurate size, please specify in (m²) which areas cannot be covered with solar panels.
Shading
Roof shadings arise from trees, antenna, neighboring houses, chimneys and other obstacles. They reduce the energy yield.
Please estimate whether your roof is affected by shading. This information is of crucial importance for the planning and configuration of your solar power system by a specialist installer.
Set-up angle
The set-up angle for the mounting of flat or ground mounted systems affects the performance of the photovoltaic system in many ways: Due to the mounting of the modules is among other things:
- an optimal angle of inclination to the sun,
- the ventilation of the modules is guaranteed and
- the self-cleaning effect of the modules by rain or snow is utilized.
For systems in northern Germany we recommend a set-up angle of 20°.

Performance Ratio
The performance ratio is a location-dependent indicator for assessing the quality of the pv-system. It results from the ratio between the optimal and the real yield and takes into account the total losses of the entire system, inter alia, through cables, meters and contacts. This indication influences the efficiency of pv systems even more than the location factors. Today´s pv systems have a PR of 0,75-0,85.
Set-up angle
The set-up angle for the mounting of flat or open area systems affects the power of the pv-system in many ways. Flat roof or open area systems have a greate influence on the power of the pv-system: Due to the mounting of the modules is, inter alia,
- an optimal angle of inclination created to the sun
- the ventilation of the modules guaranteed
- the self-cleaning effect utilized by rain or snow
For pv systems in northern germany we recommend a set-up angle of 20°.
For you as a benchmark:
For 1 kWp installed maximum power, it is required
with silicon modules: | about 8 m² pv-area |
with thin-film modules: | about 11 m² pv-area |
Please note: In case of flat roofs or open area systems, only about one third of the available area can be counted as a pv-area. To avoid mutual shading, a certain distance between the rows of modules is necessary.
Annual safety margin
This value describes the assumed annual degradation of the pv-system performance (standard 0,25 %)
guaranteed feed-in remuneration
The EEG (Renewable-Energy-Act) provides operators of a solar power system a fixed feed-in renumeration over 20 years plus the year of commissioning.
(The stated value contains the security margin)
Calculation basis
Depending on the system size, different shares of the generated electricity are remunerated. Since january 2016, the limit of the system size is 100 kWp.
If the limit is exceeded, the feed-in remuneration will be reduced to 80% of the current valid remuneration rate. (§ 38 Satz 2 EEG). Pv-systems above 10 MWp do not receive feed-in remunerations.
A more detailed calculation is offered in our profitability calculation.
Feed-in tariffs
The Renewable-Energy-Act (EEG) provides a gradual reduction of the feed-in remuneration. Thus, the time of commissioning determines - apart from the system type, the system size and the share of self-consumption - The amount of remuneration for electricity fed into the grid.
Adaption of feed-in remuneration according to EEG 2017:
The feed-in remuneration applies for a period of 20 years plus the year of commissioning. The amount is determined on the basis of the pv capacity of the previous six months. If the expansion of pv systems exceed or fall below the target value defined in the act (2,5 Gigawatt per year), the monthly reduction of the remuneration rates will be adjusted automatically. The correction of the basis degression takes place on a quarterly basis.
If there is no concrete rate of degression for the chosen date of commissioning, a non-binding forecast-value based on the current market situation is expected.
Please note: The existing fixed feed-in remuneration since 01.08.2014 only exist for small pv systems. Since 2016, operators of pv systems with a power of more than 100 kWp, have to sell their solar electricity directly on the market.
A degression value is already known for this month.
Effective annual local radiation
This value describes the effective annual solar radiation at the location on the horizontal plane, in consideration of temperatur and wind influences.
Enter your object data or supplement the existing information.
For your information: All yellow fields are required to determine the expected yield and profitability.