What is the difference between cell, panel and module?

It’s a very common question that arises when it comes to photovoltaic is the difference between the cell, the panel and the photovoltaic module. The cell is nothing more than the basic unit to form a photovoltaic panel. Since the panels are normally fitted together to form a photovoltaic module.

Does the photovoltaic panel generate power on cloudy days?

Yes. PV systems do not need a clear day with plenty of sunshine to operate. In fact, even on cloudy days they produce electricity, but to a lesser extent than on clear days.

Which are made of solar cells?

Solar cells are usually made of super thin slices of ingots of crystalline silicon (c-si), thin films of amorphous silicon (a-si), cadmium telluride (CdTe) or copper diselenide (gallium) and indium (CIS and CIGS).

How are solar modules made?

There are two ways of manufacturing solar modules:

The first is using solar cells made from silicon thin slices in crystalline form. Usually, they are enclosed in glass, with aluminum frame. This technique is the most traditional and, currently, there is larger-scale production on a commercial level.

The second way is to manufacture the modules through plasma application (almost a “spray”) of a semiconductor material on a glass or other material (which may be flexible) and serves as a “bed”. Then, this assembly is covered by a transparent material, such as glass. This is the so-called thin film technology, easier to be integrated into urban buildings. The elements used in this case are silicon (in its non-crystalline form, which is called amorphous silicon) or chemical compounds such as cadmium telluride (CdTe) or copper diselenide (gallium) indium (CIS and CIGS).

Is there any difference between collector and solar module?

Yes. While the solar module converts light energy (visible spectrum) into electrical energy, the solar collector uses heat (infrared radiation) to generate heat (water, usually).

Why are solar cells blue?

The solar panels with crystalline silicon cells are usually blue because this is the color with which the cell has the best efficiency in converting solar energy to electricity. When they arrive at the factory,  ‘wafers’ silicon are in dull gray color, the natural color of this mineral. In one of the last steps in the manufacture of solar cell, it receives a nanometer thick antireflexive layer (typically silicon nitride), which turns it into celestial blue.

Which technology is more reliable?

There are no differences or other technology. What will ensure the reliability of the installed system are the quality in manufacturing (which can be verified with the quality tests outsourced) and proper installation (for example there are specifications that require certain modules to be installed with specific drives). The main risk to the reliability of the system is, in fact, inexperience and lack of knowledge when you installed and sized.

What technology is cheaper?

The amount paid by the PV system depends on the type of application and the design goal, considering the limitations. For example, if a large area and availability of a fixed amount of desired power, the most suitable is the use of thin films. This technology is usually cheaper but has a lower efficiency. But if there is little area available for the desired power, you need to get modules with greater efficiency, which are usually more expensive.

Which technology should I take for my project?

Again, it is necessary to determine what the project needs to be able to define what would be the best technological option. First you need to assess the energy aspects: how much power do you want? Secondly it´s important to evaluate the architectural aspects: the esthetic will be an important point of the project? Then you need to compare the available area against the installed capacity will be needed to verify whether modules more efficient or if the available area isn´t a problem.

Where can I find Brazilian standards and legislation on PV energy?

ANEEL published in 2012 a normative resolution that creates a power compensation system through which consumer are credited on their electricity bill for the energy they generate and don’t consume (and that is injected into the power grid). This is RN 482/12 and you can learn more about it here.

To learn about step-by-step installation of a photovoltaic system, we suggest you access our online brochure What should I do have electricity in my house? (Como faço para ter eletricidade em minha casa?) – Only in Portuguese.

I have doubts about the certification of photovoltaic equipment such as modules and inverters (list of certified equipment). Where can I find further information?

We designed a webpage that deals exclusively with this topic. Access here.

We also suggest you access the study “Condições de Importação de Equipamentos de Mini & MicroGeração Distribuída Fotovoltaica no Brasil” (Only in Portuguese). 

How much does it cost to install a PV solar system?

In 2014, the range price charged from PV installers in Brazil was around R$ 8,69 per Watt pic (Wp) of installed power, according to Instituto Ideal annual study  The Brazilian market of distributed solar PV generation”.  If we estimated that your house needs a solar system of 2 kWp to supply your electric needs, your investments should be around R$ 17,380.00

Remember that the amounts vary according to site conditions, which dictate the best module technology to use (such as local irradiation, conditions of roof or surface where modules will be installed), and only a specialized company is able to establish the right cost for your energy demand. You can find the company nearest to your city on our Map of PV Industry Companies. 

Learn more at Advantages and Cost section.

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