Frequently asked questions and answers

In July, a new government program called “Mój Prąd” appeared, supporting the installation of photovoltaic installations. The program’s beneficiaries can be individuals who decide to install an installation with a capacity of 2 to 10 kWp. The subsidy amounts to PLN 5,000.

In accordance with the regulation of the Minister of Investment and Development of December 29, 2018, from January 1, 2019, individuals can deduct expenses incurred for the installation of a photovoltaic installation and thermal modernization of a building from their income tax base.

We also have an interesting loan offer from BNP Paribas bank. The Zielona Energia investment loan has an attractive interest rate – 3% for a period of up to 5 years, and 4.2% for a period of up to 10 years. Loan amount up to PLN 60,000.

Opinions are divided. Some customers believe that this is the case because it is the only way for them to finance their installation. Others, however, claim that it is not worth it because the whole process is too long. Unfortunately, the latter are quite right, because the service and preparation of full documentation also cost money, although many companies swear that it is free. In addition, an important aspect is the need to pay income tax on the subsidy. The subsidy also involves taking out a loan for the remaining amount. Interest and commissions therefore generate additional costs. A common requirement is also to insure the installation with a preferred insurance company. In practice, about 10% of the obtained subsidy of around 30% remains in the customer’s pocket. Of course, assuming that the system costs several dozen thousand zlotys, the amount saved is already quite large.

Depending on the power of the installation, prices are at the level of PLN 3,500 – 6,000 gross per 1 kW of power. The price of a 4 kW photovoltaic installation is at the level of PLN 20,000 gross.

The average payback time for the installation is around 5-8 years, however, taking into account the subsidy system, the installation may pay off faster. The payback time of the photovoltaic installation is influenced not only by the subsidy, but also by the amount of energy used on an ongoing basis, the price of energy and the value of VAT.

The installation consists of several basic elements, i.e. photovoltaic modules, inverter, cabling, structure, overload and surge protection.

A photovoltaic installation can power all electrical devices in your home or business.

Poland has almost identical solar exposure conditions to Germany, which is the world leader in the number of installed photovoltaic installations. Solar exposure is about 1000 kWh/m2 per year, which gives us a yield of 240-320 kWh per year from one photovoltaic module.

The impact of the assembly kit and the panels themselves on the roof load is small, as their weight is only 20 kg/m2 of surface. For comparison, a layer of snow a few centimetres thick weighs much more. The assembly systems are designed in such a way as not to interfere with the structure and stability of the roof.

Photovoltaic panels are protected by a layer of tempered glass, so hailstorms and heavy rains are not a threat to them.

Shade significantly reduces the efficiency of the photovoltaic system, but this effect can be reduced by equipping the modules with power optimizers. Thanks to them, shaded panels do not affect the operation of the remaining unshaded parts of the system.

A prosumer is a person who produces electricity from renewable sources and is also its consumer.

The surplus energy is transferred to the power grid and drawn back during periods of increased consumption or in winter, when energy yields are not sufficient. In the case of a photovoltaic installation with a capacity of less than 10 kW, we can collect 80% of the energy we have stored, and in the case of photovoltaic installations with a capacity of more than 10 kW, we can collect 70% of the stored energy.

Unfortunately, changing the contract is necessary. All formalities are carried out on the basis of the photovoltaic installation notification, which our company prepares on your behalf. So you don’t have to worry about anything, because everything will be taken care of by an experienced company, which we are.

According to current legal regulations, the distribution network operator is obliged to replace the old meter with a bidirectional meter. The investor does not incur any costs in connection with this. The only obligation is to report the installation of the system, which our company does on behalf of each client.

Yes, in accordance with the Act, the operator has 30 days to accept the notification and connect the installation to the power grid.

Settlement takes place in bimonthly, semi-annual or annual cycles, depending on the customer’s preferences. The power plant counts the energy produced by the installations and consumed by the user. After balancing these two numbers, the power company issues an invoice. A shorter settlement period does not affect the profitability of the PV system because each invoice contains information about the amount of excess energy to be used during the next year.

Theoretically yes, there are so-called off-grid systems, however such installations are currently several times more expensive. The system must be equipped with an energy storage that will provide us with an energy reserve for at least a dozen cloudy days.

In such a case, it is necessary to apply to the operator for an increase in the connection capacity. After obtaining a positive decision, the installation can be carried out. As always, our company takes care of all the formalities.

Depending on the size of the installation, the installation process usually takes 1 to 2 business days.

The photovoltaic installation is 100% maintenance-free.

It is possible, but it is much more profitable to select the installation in such a way that it produces energy only for our current needs, because the price of electricity for 1 kWh sold is approximately PLN 0.245.

The lifespan of a photovoltaic system is expected to be 25 – 30 years.

Photovoltaic panels do not require washing. Rain is sufficient to keep them clean, but periodic maintenance of the system can slightly increase its efficiency.

The best exposure is a sloping roof with an angle of 30-45 degrees with a slope facing south. However, it should be remembered that a different configuration of roof slopes does not exclude the profitability of installing the system. We also successfully install systems facing east and west.

For a 3 kWp installation, approximately 20 m2 of space is required on a pitched roof. For larger installations, it must be assumed that 1 kWp takes up 6 m2

Photovoltaic installation can be mounted on the ground, on pitched roofs and flat roofs. A wide selection of mounting systems does not disqualify any roof covering.

A building permit is only required if the nominal power of the photovoltaic installation exceeds 50 kW or the building is under the protection of a monument conservator. In extreme cases, notification of the installation is required.

There are two types of guarantees for photovoltaic panels:

• warranty against hidden defects – 12 – 15 years depending on the manufacturer
• power guarantee (after 25 years our photovoltaic modules must generate at least 85% of the rated power)

Photovoltaic module manufacturers guarantee that:

• after 5 years, the module efficiency will be 95%
• after 10 years, the module efficiency will be 90%
• after 25 years, the module efficiency will be 85%

The difference is noticeable at first glance, as these panels differ in color. Polycrystalline are navy blue, while monocrystalline are black. Another basic difference between these panels is efficiency. Polycrystalline modules achieve 16% efficiency, while monocrystalline panels achieve around 18%. Of course, this is reflected in the price.

The inverter is the heart of the photovoltaic installation, it converts direct current (produced by photovoltaic modules) into alternating current that flows in our sockets.

Inverters are generally divided into two types:

• island – used in off-grid systems to charge batteries. They cannot be connected to the power grid,
• grid – inverters used in on-grid systems are adapted to work with the power grid.

Choosing the right inverter is one of the key issues, next to choosing modules, when designing a photovoltaic installation. Its selection affects the reliability and efficiency of the system. A poorly selected inverter can be a source of much lower energy yields (even several dozen percent). In addition to the electrical features of the inverter, an important issue is the method of transmitting data on energy production to the user. Graphic LCD displays, Bluetooth and WiFi for online system monitoring are increasingly common conveniences from leading manufacturers.

Most inverters on the market are designed for outdoor conditions. However, it should be remembered that it should be installed in a place with limited access by third parties. Of course, these devices are not cheap, so you have to take into account the risk of theft and vandalism.

On-grid systems are those that are connected to the electricity grid, while off-grid systems are those that use batteries to store energy.

In traditional PV systems (without optimizers), each panel works like the weakest or most shaded panel in the series. By using optimizers, each panel works independently of the others at its maximum power.

The operation of power optimizers is to search for the maximum power point at the level of a single PV module. As for the idea, the power optimizer is to load the module in an optimal way, i.e. one that, in the given lighting conditions, provides the highest possible power at the output regardless of the current and voltage generated by the other modules in the series.

A single photovoltaic cell consists of a silicon wafer. An electron-collecting electrode in the form of a grid is placed on the upper surface of the wafer, and an electrode in the form of a metallic layer is applied to the lower surface. Single silicon cells are made in dimensions of 10×10 cm and 15×15 cm and are able to generate a current of 3-7 W. In practice, the power obtained from one cell usually does not exceed 5 W.

Each module consists of silicon cells connected in series and/or parallel. The modules are laminated with transparent foil at the top and bottom, thanks to which the cells remain in a vacuum. The module is protected against mechanical damage by 3.2 mm thick tempered glass. Properly polished tempered glass also reduces the amount of reflected solar radiation, limiting energy losses. An aluminum frame is used to stiffen the entire structure.

The basic difference between solar collectors and photovoltaic panels is that collectors produce thermal energy, which is used to heat domestic hot water. Photovoltaic panels, on the other hand, are used to produce electricity.

The roof angle should be between 10 and 60 degrees, preferably facing south, south-west or south-east.

The flat roof mounting system consists of special ballasted frames to prevent the panels from being damaged by gusty winds. The frame allows the PV modules to be tilted at an angle of about 15 degrees to imitate the arrangement of the panels on a sloping roof, thus increasing the efficiency of the photovoltaic installation. An undoubted advantage is the lack of interference with the tight roof covering.

The installation system on a pitched roof varies depending on the type of roof covering. Usually, we deal with ordinary corrugated roof tiles, between which we screw special hooks directly to the roof truss. In the case of metal roof tiles, we use double-threaded screws with double sealing, also screwed to the roof truss.

Photovoltaics should not be installed on asbestos because it becomes brittle with age, and the asbestos fibers it contains are very harmful to health. Additionally, all asbestos products should be dismantled by 2032, and photovoltaic installations are planned for a longer period than 2032.

Roof orientation and slope – as mentioned earlier, it should be south with an angle of inclination of 10 to 60.

Shade – should be as small as possible, because it has a very negative impact on the amount of energy produced.

Quality of workmanship – incorrectly designed or poorly executed installation is a common cause of low installation efficiency and customer dissatisfaction.

This way they can overheat, which reduces their efficiency. Photovoltaic modules are equipped with bypass diodes and a bypass system that prevents the module from overheating.

Photovoltaic panels connected together create a series called a “string”. Thus, photovoltaic modules connected in several strings are connected to an inverter, the number of which depends on the given model.

Unfortunately no, photovoltaics do not work at night because the basis for energy production is the emission of solar radiation.

The photovoltaic installation does not generate any pollutants, such as CO, NOx, hydrocarbon compounds or dust.

No, the photovoltaic installation (on-grid type) will not produce electricity for safety reasons. This could result in an electric shock to a power grid employee.

According to building law, lightning protection is not required in most cases of photovoltaic installations.

Thanks to the installation of photovoltaics, real estate prices increase because after installing photovoltaic panels it is largely energy independent.

• annual reduction of electricity costs by 80-85%,
• independence from energy price increases,
• use of the latest technological achievements, which provide certainty of operation for years,
• reduction of harmful CO2 emissions

Yes, it makes sense because the law is not retroactive. If the new regulations are more favorable, there will certainly be an opportunity to switch to the new rules.

With current regulations and prices on the photovoltaic market, in most cases they are not very profitable, because they can increase the price of the photovoltaic installation by up to 50%. However, there are exceptions, such as installation in facilities to which the supply of power is very expensive.

The maintenance costs of the installation are practically zero because the installation does not require servicing.

Dimensions – 1.65 x 1.00 m Weight – 18 kg Power – 270-300 Wp

Yes of course, data can be downloaded directly from the inverter to your phone, tablet or computer.

• electricity bills from last year
• photos and dimensions of the building, in extreme cases a construction project,
• information on possible obstacles, such as trees, chimneys,
• expectations related to the quality of equipment and possible arrangement of photovoltaic panels.

Wp/kWp is the power of photovoltaic modules determined under standard operating conditions.

A 1 kWp photovoltaic installation should produce about 1000 kWh of electricity. For example, a 5 kWp system will produce about 5000 kWh per year.

Photovoltaic modules operate under the influence of solar radiation. If it is a cold but sunny day, the modules will efficiently produce electricity. In the case of solar collectors, the thermal energy of the sun is used to heat the glycol that heats the water in the buffer tank.

Of course, you can repair the roof, but this involves removing the photovoltaic modules. It is therefore recommended that at least the most problematic repair work be done before installing the PV system.