Sonne für die Energiewende

WIRSOL ist Ihr Partner für erneuerbare Energien.
Wir stehen für Kompetenz, Zuverlässigkeit, Unabhängigkeit,
Qualität und Service. Gemeinsam mit Ihnen planen und installieren
wir umfassende Photovoltaik-Lösungen jeder Größenordnung.


Photovoltaik für Gewerbe und Industrie

Das Potenzial ungenutzter Gewerbe- und Industriedächer in Deutschland ist hoch.
Heben Sie es: Mit Ihrer eigenen Photovoltaikanlage von WIRSOL! Wir unterstützen Sie
von der Finanzierung und Planung über die Installation bis zu Versicherung und Service.
Sprechen Sie uns an, wir helfen Ihnen gerne weiter – auch, wenn es um die Verpachtung
Ihrer Dachflächen oder um den Strombezug direkt von Ihrem Dach geht!

WIRSOL Solarpark mit Photovoltaikmodulen für die Energiewende mit Erneuerbaren Energien

Photovoltaik für Solarparks

Solarparks sind das Rückgrat der Energiewende. WIRSOL steht
Ihnen als erfahrener Projektierer und Betreiber im Freiflächensegment
zur Seite. Ob Gutachten, Projektierung, Finanzierung, Installation,
Asset Management, Service oder Vertragsmanagement:
Setzen Sie auf unsere Erfahrung!


Photovoltaik für die Wohnungswirtschaft

In den ersten Städten haben wir sie schon umgesetzt: Zusätzliche Einkünfte aus Solarenergie
für Eigentümer und Vorteile für die Mieter aus intelligenten Mieterstrom-Projekten. WIRSOL
sorgt dafür, dass Sie als Mieter oder Genossenschaftsmitglied ebenso wie Eigenheimbesitzer
Solarstrom von Ihrem eigenen Dach beziehen können. Wir bringen die Energiewende mit unseren
neuen Konzepten jetzt auch zum Mieter!

Frequently asked questions concerning photovoltaics

Photovoltaic systems are becoming increasingly popular. We have put together the key questions concerning photovoltaics below. Find out, among other things, about costs, feasibility, advice, taxes, regulations and service life cycles.

Is a solar system worthwhile?

The cost effectiveness of a solar system is calculated on the basis of how much the system costs and the feed-in remuneration paid to the system operator by his utility company. Depending on its alignment to the sun and how it is financed, a photovoltaic system will have paid for itself in around ten to 15 years.

What is an inverter?

Inverters form the heart of a solar system, functioning as the link between solar generators and the electricity grid. The inverter converts the direct current generated by the solar panels into alternating current suitable for the electricity grid. This is the reason why inverters are also known as grid feed-in devices (abbreviated to NEG in German). Parallel to this, inverters also store operating data and monitor the solar generator’s grid connection. As a general rule, one inverter is used to serve several strings of solar panels.

What types of shading are there?

Photovoltaic systems can be affected by many different forms of shading. When structuring the panel layout it is thus particularly important to take care that the panels are not shaded. The various types of shading include:

      • Temporary shading – caused, for example, by fallen leaves, snow, bird excrement or dust. These temporary shading elements usually dissolve without action being taken – for example when rainwater flows over them.
      • Partial shading – caused, for example, by adjacent houses, trees, chimneys or aerials. Even minor partial shading can result in significant impairments in the system’s performance since the weakest solar cell dictates the intensity of current, causing the overall performance of the photovoltaic system to decrease. The shading caused by an aerial can already result in a 10 to 15 % decrease in System performance.

What is a solar panel?

Solar panels consist of individual, interlinked solar cells. They are either encapsulated between two panes of glass or between glass and a rear sheet of film. This ensures that the solar panel is weatherproof and stable. Panels can be manufactured with and without metal frames. Models built without frames are also known as laminated panels.

Are photovoltaic systems recyclable?

The eco-balance of photovoltaic systems remains positive throughout their life cycles. This is due to the fact that all components – such as glass, aluminium, plastics, silicon and other cell materials – are recyclable.

What does ‘photovoltaic’ mean?

The word “photovoltaic” is made up of the Greek term for light (photo) and name of the Italian physicist Alessandro Volta. He also gave his name to the unit of measurement for electric potential. Photovoltaic thus describes the transformation of sunlight into electric energy using solar cells.

Which angle of inclination is suitable for photovoltaic units?

The angle between the solar panel and the horizontal axis is known as the angle of inclination. The ideal angle of inclination depends on the degree of latitude on which the system is located. Due to the curvature of the earth the difference between northern and southern Germany is already several degrees. Our experts will be pleased to help you check your roof’s inclination.

What different types of installation are there?

Photovoltaic systems can be mounted on a variety of subsurfaces:

      • On sloping roofs as on-roof or in-roof Systems
      • On flat roofs with the aid of elevation System
      • On façades as so-called building-integrated photovoltaics (BIPV)
      • On areas of ground using racks or tracking systems

What is a kilowatt peak?

The maximum performance of a solar cell or panel is calculated in kilowatt peak (kWp). This performance represents maximum power point performance (MPP) under standard test conditions (STC). This method is used to describe the overall performance of the generator field in a photovoltaic system. In purely mathematical terms, 1 kWp can produce from 800 to 1 000 kWh electricity. An area of 8 to 10 m2 is required for this purpose.

What is a stand-alone power system?

Stand-alone power systems are off-grid – i.e. they are not connected to the public electricity distribution system. The direct current produced in this way is used at source. Insofar as you would like to use the energy you generate independent of whether the sun shines, power is stored in batteries. A special inverter is required for this purpose – for example so that domestic appliances can be connected to the system.

What do I have to take into consideration if I have a flat roof?

When panels are used on a flat roof they are installed using a corresponding system to mount them at an angle. It is essential that the roof’s statics are checked before such a system is installed. This is the only means to establish whether installation can go ahead and the roof area can bear the load. The inspection also provides information about whether there are roof points or walls which could bear the additional load. Modifications to roof cladding are not required for most installation systems. In specific terms, this means that professional installation will avoid the risk of water damage.

How does a feed-in meter work?

A feed-in meter measures the amount of energy generated by the photovoltaic system and fed into the public grid in kilowatt hours (kWh). Following the introduction of statutory fixed minimum remuneration within the scope of the German Renewable Energy Sources Act (EEG) PV systems connected to the grid must be equipped with such meters. As a general rule feed-in meters are installed next to existing consumption meters.

What regulations does the German Renewable Energy Sources Act include?

System operators receive statutory feed-in remuneration for any electricity they feed into the public grid. In Germany this is regulated within the scope of the Renewable Energy Sources Act (EEG). Network operators pay for the number of kilowatt hours fed into the grid, subsequently including the costs of such payments in their electricity tariffs. The tariff for feed-in remuneration decreases at regular intervals, with the aim of forcing the market to reduce the required investment costs and thus also prices.

Are network operators obliged to purchase my electricity?

Electricity utility companies are obliged to purchase power generated by photovoltaic systems with a capacity of up to 30 kWp. Since domestic systems are generally smaller than this, there is no problem obtaining a connection to the grid. Systems with a capacity of more than 30 kWp must have a so-called DC isolating switch, which allows the network operator to disconnect the system from the grid. In addition to this, you must always apply to the relevant electricity company to have the power supply lines checked. The inspection must establish whether the power supply line to the next feed-in point is equipped to take up sufficient quantities of electricity. Should this not be the case, then the supply line must be increased as required.

What are the operating costs for a solar system?

As a general rule, the operating costs for a solar system are relatively low. The only items they include are contingency sums for possible replacement of inverters and to insure the system.

Do I need a lightning protection for my solar system?

In Germany, regional laws specify that lightning protectors must, as a matter of principle, be installed on public buildings. Installation on private buildings is voluntary and not generally necessary. Should a lightning strike cause damage to the system, then this will be covered by its insurance.

What are thin-film solar cells made of?

Thin-film cells are even thinner than crystalline silicon cells. They are made up of amorphous silicon, copper indium gallium diselenide (CIGS) or cadmium telluride (CdTe). The proactive semiconductors are applied in thin layers to glass, metal or plastic film.