Building our own Solar Power Plant

The solar power plant and its power panel selection.

The size of the solar power plant we install should be based directly on our annual electricity consumption. It makes no sense to buy too large a photovoltaic installation because at the moment it is not possible to sell electricity to the energy company. Currently, we can balance energy, so we cancalculatethe excess we send to the power company and recover 80% of it when we need it or use what we produce directly for our own needs. It should be borne in mind that one kWp of a photovoltaic module will produce about 1000 kWh of power annually. If our annual consumption is about 2000 kWh, we should design a power plant with a capacity of about 2000 kWp. However, if our consumption is as much as 10,000 kWh per year, we should consider a 10 kWp power plant. (kWp is the power of the PV module expressed in watts.)

When buying solar panels it is important to purchase a name brand from a known source, and not one of thecheap Chinese productions. The solar panel used in the installation of a solar power plant should have a linear power warranty which guarantees high efficiency for a full 25 years of use. It is also important to make sure that the solar panels are certified for ammoniatoprevent pitting in the solar cells and costly replacement after a few years.

Selection of grid inverter

The grid inverter, otherwise known as the inverter, is responsible for changing the direct voltage generated by solar panels into the alternating voltage of 230V or 400V that we have in the power grid. It is the heart of the photovoltaic system, and we must ensure that it is of high quality. The companies we recommend are Fronius SMA and Steca. They are the leading manufacturers of photovoltaic inverters that guaranteea high efficiency of over 98% and a long service life of over 25 years of operation. Please note that the cheaper Chinese substitutes produce significantly less solar energy (up to 20% less) than the high-performance brand name devices. 

Installation site of the solar power plant.

The best place to install solar panels is on the south side of the roof, angled between 25 and 50 degrees. Care should be taken that solar panels are not installed in an east-west direction or, even worse,towards the north. They should face the south with a slighttiltto the east or west of preferably no more than 15 to 20 degrees.

An alternative is to install the solar panels on the ground on adedicated structure integrated with the ground, by driving piles for example,or to place it on another type of structure not integrated with the ground. This option is much better because it does not require a building permit.

Solar power plant overvoltage protection.

Without exception, every solar power plant should have overvoltage protection both on the DC side (i.e., on the side of the solar panels that generate DC voltage) and on the AC side (i.e., on the side of the electricity supplier–230V or 400V alternating voltage). This type of AC/DC overvoltage protection will protect us against lightning during a storm and against overvoltage coming from the power grid. In the worst case, we wouldonly lose a fuse worth PLN 100 or PLN 200, depending on the model, and not an inverter that can cost up to several thousand or more PLN. Even if the installer/solar power plant contractor does not see the need for such security measures, we should strongly insist that they be installed.

How to choose a renewable energy installer

When choosing a solar power installer, you should look for a professional contractor who has been in the market for many years. It is not a good idea to choose a company founded only recently in response to the growing wave of popularity for solar power plants, because the installer’slack of experience can lead to serious errors in the design of the photovoltaic installation itself. It is also not a good idea toaccept the installation offers of energy companies and large sellers (e.g., furniture or other large stores) because theinstallerwill almost always be a subcontractor and if we need to report problems with the installation we will be forced to contact the energy company or the store, and not be able to deal directly with the contractor who installed the solar power plant.

“My Electricity”Photovoltaic co-financing

Currently, our country is running a nationwide solar power plant financing program called My Electricity. This means that after presenting the invoice for the purchase of a solar power plant connected to the grid, we can geta state reimbursement of PLN 5,000 for each photovoltaic installation. The application for co-financing must be submitted to the National Fund for Environmental Protection and Water Management along with the purchase document and a signed contract with the energy company for energy balancing.

What to Avoid When Installing a Solar Power Plant.

Choosing a photovoltaic installation–a solar power plant–is a decisionyou will live with for many years. Each solar power plant should be planned for a minimum of 25 years of continuous operation. The worst possible choice is thepower plant with the lowest price. Budget Chinese photovoltaic installations are characterized by low efficiency and a very high failure rate. If we want our power plant to operate for a long time and without failure, as well as to work efficiently without major problems, we should choose proven brand-name products.

Our company does not offer solar power plant assembly services. We only sellthe necessary components.