PV modules, inverters, energy storage, heat pumps and more! Here you will find answers to bothering questions about the components from our offer.
Our FAQ’s will answer those questions and more!
Photovoltaic modules
Are modules and panels the same thing? Structure of a photovoltaic modules.

Yes, these terms can be used interchangeably. A module or panel is a set of interconnected photovoltaic cells that produce electricity in the form of direct current.

The term “panel” appeared in Poland as an English loanword and has been in use on our market for several years.

It is also useful to know what a photovoltaic cell is. It is a single junction of P-type and N-type semiconductors that converts solar energy into electricity. The cells, often called wafers, generate a low DC voltage when exposed to light. For the most common silicon cell, it is about 0.6 V. To obtain a useable voltage (around a few dozen volts), the wafers are connected in rows by solder or glue. The standardised number of 60 silicon cells can achieve around 40 V. The voltage of a single cell will vary depending on the material of the semiconductor. Therefore, string lengths vary, which directly affects the electrical performance of the entire photovoltaic module.

Strings of cells are often connected in parallel to obtain more power for the entire module.

A module is a collection of individual cells, so the wrongly derided name, “photovoltaic cell battery,” is the correct one.

In contrast, the term “solar collector” should not be used as it means a device used to convert solar energy into thermal energy.

How does a PV module work?

Sunlight is a stream of photons. When it falls on a photovoltaic cell, i.e., a P-N junction, it causes the electron-hole pairs to break apart. The released negatively charged electrons and positively charged holes accumulate at opposite poles of the cell, generating a constant flow of voltage. When the electrical circuit is closed, electrons travel from cells connected in rows toward positive holes through metallised contacts to equalise the potential. The electrical current created in this manner can be processed by a photovoltaic inverter or used, for example, to power DC loads.

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PV inverters
What is an inverter?

PV modules produce electricity in the form of direct current. The inverter’s job is to convert this energy into alternating current that is compatible with the electricity in the power grid.

What is the difference between an inverter and a micro-inverter?

Micro-inverters are devices that enable the conversion of direct current to alternating current from one or more PV modules. Unlike standard string inverters, which are placed further away from the modules, for example, on a wall in the service room, micro-inverters are fitted directly underneath the PV module. This minimises losses as less DC wiring is required, and it cuts out the cost of DC circuit protectors which are needed for string inverters. Such configuration significantly improves the installation’s safety as the maximum DC voltage that flows through the system is that of a single module. In addition, there is no need for any protection on the DC side. Micro-inverters are connected in parallel to one or three phases of AC wiring that leads directly to an AC switchboard.

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Energy storage systems
Do energy storage systems guarantee independence from the grid?

Energy storage is a particularly effective way to increase your energy autonomy. During the summer, daytime power production often exceeds the demand at any given time. In a standard installation, the excess is sent to the grid and the prosumer can collect it later. However, the grid owner takes 20–30% of the energy received. Whereas installations equipped with an energy storage system, redirect the electricity straight to the batteries, and the installation owner does not lose any kilowatts produced.

Owners of inverters with UPS or ESS function are also protected against power outages. The inverter will switch to emergency power mode and begin drawing power from the charged batteries. The prosumer will therefore be able to use electrical appliances despite the lack of electricity in the area.

Achieving full energy independence under current technical conditions is justified in places where there is no power grid. The optimal solution is to increase self-consumption in on-grid installations by using batteries.

How to choose an energy storage system?

The first step is to determine energy requirements. To do this, the prosumer should contact their installer or an advisor and analyse electricity bills from recent years as well as additional needs, such as  protection against power outages.

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PV installation designs
Can Solfinity design the entire installation and prepare the necessary documentation?

Yes, our design team can create a complete design of any installation up to 3 MW and prepare all necessary documents. Please contact your account manager for details.

How long does it take for Solfinity to prepare a PV installation design and how much does it cost?

The time of execution and pricing of the design is an individual matter which depends on many factors. In most cases, this should take no more than 7 business days. Please contact your account manager to discuss details.

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Other questions
What does a PV installation consist of?

The basic components of any PV systems are the photovoltaic modules and the inverter. Photovoltaic modules are the muscles of the installation that are responsible for production of energy. The inverter converts direct current generated by the panels into alternating current and monitors the operation of the entire system. Thanks to the inverter, we know how much electricity the home power plant has generated. It is the brain of the entire system.

An installation also includes connecting cables that connect the modules to the inverter and the inverter to the switchboard. A vital component is the mounting structure, which ensures that the PV modules are securely attached to your roof or the ground.

Building your own PV system is expensive, so it is important to make sure it is safe. Electrical protections such as surge arresters are an important part of this.

To maximise energy yields, it is also worthwhile to consider purchasing power optimisers.

For those who want to store the energy produced, we propose to enhance the installation with an energy storage system.

How do Tigo power optimisers work?

Tigo power optimisers search for maximum power point at the level of a given module to which they are connected. These allow the module to achieve the highest possible capacity it can at any given time, regardless of how much power other modules are generating. An installation without optimisers works as well as the weakest panel that is, e.g., in the shade. By using optimisers, we improve the operation of the weakest panels so that the entire installation works even better.

This is a perfect solution, for example, when the module is partially shaded or when the roof has many slopes.

The big advantage of Tigo power optimisers is that they are fully compatible with most inverters and that they can be fitted to modules that require it and not to all modules in the installation.