Planning a solar park is not child’s play. Too many factors are at play here. First of all, it matters where exactly your site is located. How often does the sun shine there on average and with what intensity? Depending on the local conditions, a coordinated project drawing is created. In addition, the electrical data of the future PV system must be determined. Depending on the size of the area, a different number of PV modules can be installed. You’ll also need to buy some inverter chargers.
The more modules are installed in the solar park, the higher the overall performance of your solar power generator system. Once this work is completed, the finished solar park can be projected into it. If everything fits, the final yield calculation takes place so that your investment is secure. No matter how large the solar park is to be, careful planning is immensely important. The PV system must work very reliably over a long period of time. After all, the investment should flow back into your pocket relatively quickly.
As soon as the building permit has been granted and the grid operator has checked the grid compatibility on site, your solar park can be built. The PV system is created here first. The photovoltaic modules of a PV system are mounted on metal frames. This means that the alignment and inclination of the solar modules are optimal.
The racks are usually quite low, but there are also racks that allow agricultural use below the plant in parts. The distance between the modules is several meters so that the modules do not shade each other. Incidentally, the direct current generated is converted into the required alternating current on site and immediately fed into the power grid. To do this, however, the network operator must be given more remote control options.
For the PV system, the supports for the supporting frame are first rammed. It is of great importance to pay attention to plumb alignment and alignment. After all, depending on the size of the solar park, several thousand supports are required.
The trenches for the power lines will then be dug. This is done quite normally with an excavator. In addition, the cables are laid to the inverter stations. Now you can start mounting the mounting rails, which are essential for the PV modules. All this takes about 3 weeks up to this point.
A good time for an interim acceptance. Here the inclination and alignment of your system is checked. Once the entire support structure is complete, assembly can begin. The PV modules are then electrically connected to one another.
Since the inverters require stations, these must be installed in the next step. In addition, the DC and AC sides are connected. Of course, this work is done by qualified electricians.
A station has around four to six inverters. However, this depends on the wiring. For example, a PV solar system can have 13 stations with 3000w power inverter. This is then a decentralized inverter topology. In principle, your solar park is now complete. The connections are then checked more precisely using special measuring devices.
The logging that is done here is extremely important to you. If everything is in order, the cables of the inverter stations can be connected. This works very simply. They are simply placed on large switch disconnectors in the low-voltage distribution system. Now they are connected to the transformer (medium voltage) via a so-called busbar system. The voltage there is around 20,000 volts. As soon as electricity flows there, it will be around 1,600 amperes at full power.
The solar system is now complete. You can start commissioning. However, this requires a thorough examination of the outdoor area in advance. During assembly, especially in larger solar parks, damage can occur in the long rows of modules.
This may have happened because of the dredging work, but also because of stray animals. Such damage can cause problems as soon as the system is switched on. For this reason, a technician will inspect the exterior particularly thoroughly.
Meanwhile, another technician will adjust the system according to the grid operator’s specifications. Otherwise the stability of the network cannot be guaranteed. You have to consider that after commissioning, up to 1 megawatt of electrical power is fed into the public power grid. If there is an error, it can have fatal consequences. The system will only be gradually connected to the public power grid when everything has been completely set up and thoroughly checked and inspected.
The commissioning has long since taken place, and then the final inspection of your system is due. For this purpose, performance is measured and various security aspects are checked. With the performance measurement, it can be determined whether your solar park can produce the yields previously calculated for you.
The measurements are carried out in so-called full-load operation. They are carried out with the help of a thermal imaging camera and a characteristic curve measuring device. The data supplied in this way enable the precise creation of a performance profile. In addition, the thermal imaging camera can show any damage to the PV modules.
From time to time, such damage can occur during transport and assembly, which sometimes cannot be seen with the eyes alone. After all the data has been evaluated, you will receive a system pass. It is the basis for regular maintenance and servicing of the system.
The most important questions about your solar park
How much does a solar park cost?
A solar park costs an average of EUR 1,000 per kWp. Around 1% of the investment costs are incurred annually for the operation of the system.
Which modules are best suited for this?
Inexpensive thin-film modules are primarily used for large-area solar parks.
Are German or Chinese modules better?
As a rule, the quality of the Chinese modules is just as good as that of the German modules. In addition, Chinese manufacturers complete numerous tests and have themselves certified. The Chinese modules are popular because they cost up to 20% less.
However, there is a distinct disadvantage. The commissioned photovoltaic installer is obliged to give his customers a guarantee for the first two years after installation. If a complaint occurs and there is no Chinese contact person, this is not only a problem for the installer. In terms of quality, however, there is not a great difference.
Which inverters are suitable?
The inverter must be selected depending on the power, configuration and number of connected modules. Inverters are already available from a power of 2 kilowatts and only end in the megawatt range.
So far, so-called central inverters have mainly been installed, but now the string inverters, which are preferably used in private systems, are also suitable for large systems.
Which substructure is required?
The substructure is crucial for the stability of your solar power system. The solar modules are supported by it and it gives the whole system the necessary support.
The modules are located on the elevations and can usually be tilted in order to make the best possible use of the sunlight. In addition, special weighting areas should be part of the substructure so that even strong winds cannot cause any problems.
Steel substructures are also particularly suitable for a solar park.
Should tracking systems be used?
Tracking solar systems follow the position of the sun. In this way, more income can be generated. There are two options here, namely single-axis tracking and dual-axis tracking.
Depending on the version, the single-axis tracking ensures that the module array follows the sun horizontally according to the sun’s angle of attack or vertically according to the sun’s path.
Two-axis tracking offers both options and thus offers the highest yield. Sensor-controlled tracking systems promise optimum yield even in adverse weather conditions. Tracking systems are therefore quite useful.
What monitoring systems are there?
Monitoring systems inform you about the performance of your system. Depending on the system and monitoring mode, you will receive data on yields, the level of self-consumption and the level of feed-in, among other things.
You can also use these systems to draw initial conclusions about the current functionality of the system. If the data deviate from the norm, something is wrong with the system.
The monitoring systems include normal meters that you can read yourself as regularly as possible in order to be able to collect the data in a meaningful way.
So-called data loggers, i.e. electronic data storage devices, are more convenient here. They monitor the system fully automatically and record yields and other parameters relating to the system’s performance around the clock. A data logger receives the necessary data from the inverter.
What would the profitability look like using an example?
An annual electricity yield of between 400,000 and 500,000 KWh per hectare is normal. Up to an output of 10 MW, a feed-in tariff is granted for solar systems according to the EEG. Of course, the system must be located on an eligible area.
Depending on the development, the feed-in tariff is around 10 cents. In this way, the economic use of a solar park is given in any case. In addition, the prices for modules continue to fall, while electricity prices continue to rise. For this reason, an investment is very worthwhile today, even without state subsidies.
Is there anti-theft protection?
There are ways to protect your own solar panel system kit from theft. This includes special screws that have been processed in such a way that disassembly is only possible by drilling.
In this way, you can quickly track down your property in the event of theft. Ultimately, most insurers require secure fencing for solar parks anyway. Camera surveillance and an alarm system are also options that make sense.
How much time elapses from planning to commissioning?
Depending on the size of the area, it takes around eight weeks from planning to commissioning. Most of the time falls on the official approvals. The construction itself is usually completed within three to four weeks, so that the solar park can then go into operation.
Can the electricity produced also be used by the company itself?
Yes, the electricity produced can generally be used as required. The electricity not used by the company is then fed into the grid.