Common mistakes
According to Andrias Jonušauskas, the project manager of the renewable energy company Energobalt, there are two types of errors in the installation of solar power plants: technological and qualitative.
“In the first case, the wrong materials are used. For example, cables of the wrong specification are selected, installation pipes that are not UV-resistant, metal fasteners that are not corrosion-resistant, or improperly attached solar panels.
I would classify quality errors as work that is rejected, when due to lack of time, knowledge, and sometimes lack of desire, the installation of the power plant is messy, improperly assembled. Most often, electrical cables are left unattached or improperly attached, using screws or self-tapping screws that are not intended for outdoor work,” the specialist points out, adding that relatively often all defects are caused by simple non-compliance with the installation instructions provided by the manufacturer.
According to him, perhaps the biggest problem is that people who order solar power plants blindly trust the hired installers and think that they will do the work properly. In addition, many people do not feel that they have enough knowledge to appreciate the work of craftsmen. However, Vilius Ivanauskas, manager of Energobalt, says that anyone can check the main aspects of the installation of a solar power plant and it does not require special competences.
“It’s a mistake to think that – “oh, I don’t know anything, so I won’t go in”. First of all, it is necessary to observe the installation process. If you see something that you think is wrong, tell the masters about it. If these comments are not taken into account, the management of the company or at least the representative of the sellers with whom you communicated should be reported. I would also recommend inspecting the roof after installation. Assess how the cables are fixed, whether the connections are not lying in the bends of the roof, where the most water flows, whether the modules and fasteners are not distorted, whether the roof is not damaged, and finally, there is no debris left behind,” he points out.
The best result can be expected by choosing structures that have not only CE (Conformité Européene) certificates, but also resistance calculations. It is they who help to best assess whether the structures will withstand the snow and wind loads typical of our climate.
“I recommend choosing such metal constructions and details that are best protected from the effects of the environment. Assess the coating of the steel and its thickness. If the manufacturer declares that its construction is covered with a Magnel coating, which is three times more resistant than a hot-dip galvanizing coating, ask for documents confirming this,” advises the expert.
His colleague also emphasizes that apparently small nuances can have a big impact on the efficient operation of solar power plants. For example, when installing a power plant on the roof, it is necessary to remember that the decking of the aluminum structure must be made of the same material as the roof. Therefore, the use of EPDM-type coatings made from synthetic rubber components on PVC coatings should be avoided. These substances are incompatible and destroy each other.
The wrong angle of inclination of the solar modules can also determine how long it will take to pay off the investment in the solar power plant. The difference whether it is installed on a slope, or on a flat roof, or on the ground is huge.
“As the tilt angle of the modules decreases, the electricity generation also decreases. On pitched roofs, they are installed at the same angle as the roof slope, and on flat roofs, they are tilted by 10-15 degrees. Certain solutions allow to obtain an angle of 20-30 degrees. In any case, installers should always evaluate the surface on which the power plant will be built and select the appropriate solution individually. Specialized software is used for these calculations, which is a mandatory work tool for experienced contractors,” the expert teaches.
Effects and risks of installation errors
According to the head of the company, the biggest mistakes in the installation of solar power plants are often made at the design stage. This one is very important, but it got too little attention at the beginning of the solar boom. Today, design-related errors are much less common. However, this process still needs to be monitored very carefully.
“Design is important for several reasons. Ideally, it accurately calculates the expected production, specifies the electrical and installation parts, lists how exactly the equipment will be located and installed, how the objects on the roof and in the path to the entrance will be taken into account, the possible roof loads are estimated, taking into account the natural conditions and etc. Accurate assessments of this kind can only be carried out by certified constructors”, emphasizes the expert.
According to him, before starting the installation work, two types of projects must be prepared: an electrotechnical work project, which contains calculations of the effect of the power plant on the electrical network, and a complete work project, where the location of installation structures, troughs, cable extension paths, transitions in walls, firewalls, is specified , how the transition holes are plugged, etc
“Usually limited to an electrical work design, but if you want fewer interpretations and more precise contractor commitments, prepare a work design as well. Yes, it will cost money to prepare it and evaluate it by specialists, because the project needs to be verified, more precise assessments to be performed, but later you will have the entire process described in detail and the contractor’s responsibility for the final result guaranteed,” the company manager pointed out.
In turn, the expert claims that defects in the installation of a solar power plant that are not noticed in time can become critical errors. These are primarily improper electrical connections. They especially reduce the efficiency of solar power plants.
“Poor-quality connections can heat up and start sparking when an electric current flows. As the temperature rises, there is also a risk that the protective layer will melt, which can cause a short circuit and even a fire. In this case, the problem will not be less generation, but much greater losses. Therefore, it is very important that the electrical work is carried out by a qualified specialist using special tools and suitable materials”, warns the manager of solar power installation projects.
The risk of large losses is also caused by trays that are not properly covered with rubber or plastic gaskets, which are used to lay cables. Without intermediate beds, the edges remain sharp and the cable inevitably rubs against them, its insulation wears out. This is especially dangerous when the voltage reaches about 1,000 volts.
According to the specialist, too small spaces between solar modules often cause problems for users – this causes the problem of shadows.
“The latter is characteristic of flat roofs and ground-mounted solar power plants, when the row of solar modules in front can cast a shadow on those behind it. When the distance between the modules is small, the time interval when there is no shadow is shortened. This is especially felt in early spring and autumn, when the sun does not yet rise as high as in summer. The larger distances between rows of modules allow them to be kept lit longer, which means they generate energy for a longer period of time.”
According to the specialist, the majority of critical errors are clearly visible. Hanging, unsecured, unprotected wires from mechanical damage will definitely trip even those who do not understand anything about electrical work. When you see such things, you should not be silent, because there is a risk that the wires will be damaged by drifting snow, wind or roof structures.
“Some mistakes are harder to spot. For example, an improperly distributed number of modules in the voltage converter inputs, underestimated shadows from various surrounding objects – trees, roof elements. There are cases when the characteristics of the solar modules are simply not suitable for the selected voltage converter, and cables with a cross-sectional area that is too small are used for the work,” he teaches.
He is convinced that it is necessary to pay attention to even the smallest details, because over a long period of use, the difference in the amount of energy generated between a properly functioning solar plant and one with defects will be quite significant.
“The most important thing is that quality work does not require a lot of additional costs or time – it’s more a matter of desire.”
Homework is the most important thing
According to a company executive, the most expensive mistakes in solar power plants are those that cost more to fix than were saved by compromising on the original price. Therefore, he advises to make decisions based not only on price.
“Talk to the contractor, listen to how many observations and comments he has about the upcoming project, find out how he plans to install the modules, what problems he sees. To be sure of the professionalism of the contractor, ask how he plans to plug the holes made in the installation process in the roof or walls where the cables will be laid. It is possible that the installers do not have enough information about the requirements of STR (Regulation of Technical Requirements for Construction) and EĮĚBT (General Rules for the Installation of Electrical Equipment), so they do everything based on common understanding. Critical mistakes are usually made that way,” he is convinced.
If you want to insure yourself against all these potential problems, experts advise you to be critical and demanding. A solar power plant is a huge household investment, so decisions cannot be made carelessly without doing your homework. When choosing a solar power plant contractor, you must also look at the terms of the contract.
“Before signing the contract, I would recommend discussing it. Explain what the solar power plant will be like, its construction. Discuss possible alternatives. Evaluate the advantages and disadvantages of each. Remember, a quality solar power plant is inevitably more expensive. However, if you spread the price difference over a longer period of time, it won’t seem so expensive. Well, to be completely calm, it is worth insuring the installed solar power plant against the effects of the environment. This will also help protect your investment,” advises the project manager.
Both solar power plant installation experts emphasize that solar power technology is constantly being improved, and progress helps reduce the number of installation errors. In other words, it’s much harder to make a mistake now than it was at the beginning of the solar boom.
There is also more information about solar energy than ever before. Larger frame manufacturers even have special programs that help you choose the right frame and complete the most suitable equipment. However, according to the interviewees, no progress will help if there is a lack of critical thinking and the necessary competencies.
“Now, I think, it is not technological progress, but the progress of competences that is more important. The ranking of solar power plants should be carried out by experienced and specialists, most importantly, those who take responsibility for the results of their work”, emphasizes the head of the renewable energy company.
