The energy market is strongly defined by rises in electricity prices and the increasingly monopolistic position that individual energy providers hold. A photovoltaic system will allow you to counteract these trends and produce your own environmentally friendly solar electricity. SOLARWATT is offering you all-inclusive photovoltaic packages to ensure that you consume solar electricity as efficiently as possible in your own home.
The more solar electricity you use in your own household and the higher your internal consumption is, the less electricity you need to purchase from your energy provider. SOLARWATT all-inclusive packages are designed to maximize internal consumption: they allow you to access solar electricity at any time, day and night, whether the sun is shining or not. High electricity bills will thus be a thing of the past.
How does a photovoltaic system work?
Solar systems generate electricity from sunlight, or rather solar energy. The sun’s rays fall on the solar cells in the modules, creating DC electricity. Since alternating current flows both in the household network and in the national grid, however, an inverter subsequently converts the direct current to alternating current.
The solar energy generated in the solar power system can now either be used directly by household appliances and other consumers, stored in a battery storage system for later use or fed into the national grid.
Generating electricity yourself – requirements and preconditions
Certain structural preconditions need to be met for the installation of a photovoltaic system. Things to be considered in advance are, for example, the orientation and pitch of the roof as well as the size and condition of the roof surface. In the case of a roof with many windows or dormers, the usable area for the PV system and the solar energy yield are reduced in comparison with a roof with no such special features. Further important factors are the roof statics and possible shading.
Preconditions for your PV system
On flat roofs the solar modules are uprighted with the aid of metal frames, while on pitched roofs they are mounted parallel to the roof surface. In case of deviations it may be necessary to mount more modules for the same output. The rule of thumb is: a roof pitch of between 20° and 30° is ideal for the generation of solar electricity.
Strength of the solar irradiation
Solar irradiation figures help plan solar power systems and are needed to determine a system’s yields. These figures are high enough almost anywhere in the world to operate a PV system profitably.
Shade can lead to a reduced output of a photovoltaic system. It is therefore advisable to observe the roof surface before the installation with regard to possible shading, including in the future due to tree growth or the neighbour’s building plans.
A roof facing south is ideal, but photovoltaic systems can also be mounted roof surfaces with other orientations. In that case, however, a larger number of modules may be required to achieve the same output.
Domestic electrical installation
For the connection to the national grid, solar cables need to be laid from the roof to the basement or the utility room.
Legal aspects related to photovoltaic systems
Legal questions always have to be observed when installing a PV system. These include the following topics: The necessity of planning permission, how the income from the system is to be taxed and guarantees/warranties for the components.
Planning permission is not normally required for a photovoltaic system on the roof of a house, since this is considered a structural measure. Special rules apply to installations on listed buildings. Further exceptions, depending on the federal state, are systems that project from the building or regulations arising from the local development plans. You can get information about the respective rules from the applicable building regulations.
Particular caution must be exercised in relation to the natural surroundings of a planned system. The building regulations specify the extent to which the surroundings may be adapted to suit the requirements of a photovoltaic system – for example, whether a tree may be felled in order to prevent shading.
Observe applicable building regulations
The applicable building regulations must be checked to ascertain whether and what changes to the surroundings may be made in order to improve the output of the PV system.
Installation of a solar system
The installation of a photovoltaic system should be carried out only by specialist companies. Our competent specialist partners in your area will be glad to help you.
The photovoltaic systems are mounted with a sub-construction on the existing roof covering and are thus particularly suitable for retrofitting PV to existing properties. The modules are mounted a small distance above the roofing tiles – it is essential to ensure sufficient air circulation behind the modules. Particular care must be taken during the installation not to damage the roofing tiles or the insulation.
In the case of tiled roofs, which are commonest in Germany, hooks are screwed into the rafters. The installer then mounts rails on the hooks to which the solar modules are fastened. Depending on the type of module, they can be bolted, hooked in or fastened with clamps. An alternative to conventional rooftop solar systems are roof-integrated systems.
Self-consumption optimisation with photovoltaic systems
What does self-consumption optimisation with photovoltaic systems mean? The central concept is to consume as much of the self-generated solar electricity as possible in one’s own household in order to reduce the quantity of mains electricity required. There is a very simple calculation behind this: The more free solar electricity consumed by the system operator, the lower the requirement for mains electricity.
This means: If you feed in solar electricity for a remuneration of 12.31 euro cents per kWh and purchase in its place mains electricity for around 28 euro cents per kWh, you still pay almost 16 euro cents for your solar electricity despite your photovoltaic system, even though the actual solar electricity costs nothing.
How can you achieve the highest possible self-consumption? Combine your solar system with a battery storage system, as in the SOLARWATT Store complete package. This stores excess electricity until you really need it. Since the electricity consumption is highest in the evening and at the weekend, you can use the stored electricity during this period instead of the expensive mains electricity.
A high self-consumption hence results on the one hand in a lower electricity bill and on the other in more independence, because the less mains electricity you require, the more independent you become from the energy supplier.
Independent thanks to high self-consumption.
The process, from the search for information to the installation and commissioning of a photovoltaic system, is very complex and requires extensive planning. We support and advise you through the individual steps. Our reliable specialist partners also help with the precise planning and take care of the installation of the SOLARWATT complete package for you.