# PHOTOVOLTAIC SOLAR PANELS SPECIFICATIONS

Do you know what the photovoltaic solar panels specifications are? In this article we will analyze the meaning of each data that appears on the labels of the solar panels.

## PHOTOVOLTAIC SOLAR PANELS SPECIFICATIONS

When we see the technical sheet of a photovoltaic panel, they give us a series of parameters that define it electrically, we will try to explain this technical data to better understand the chips given by the manufacturers. We talk about the  electrical characteristics of solar panels .

The characteristic parameters of a panel are measured by the manufacturers under standard conditions (STC): for an irradiance of 1000W / m2, a cell temperature of 25º and a spectral distribution of AM 1.5G.

The  photovoltaic panels  include a set of suitably connected cells each other, so that meet the optimum conditions for subsequent use in power generation systems, converting sunlight into electricity. For example, the 12V panels consist of 36 cells, the 24V panels for 72 cells and the so-called “network connection” for 60 cells.

The behavior of a photovoltaic cell is defined by the Intensity-Voltage (IV) curve represented below:

## Electrical characteristics of the solar panels: different parameters that are given in the technical sheet:

• Short circuit current (Icc or Isc):  is one that occurs at voltage 0 volts, so it can be measured directly on terminals by an ammeter. Its value will vary depending on the atmospheric conditions of measurement.
• Open circuit voltage (Vca or Voc):  is the maximum voltage of the panel, can be measured by not having any load connected, directly with a voltmeter, its value will vary depending on atmospheric conditions.
• Maximum power (Pmax) , measured in peak watts (Wp): it is the maximum power that the panel can supply, it is the point where the product intensity and tension is maximum, under standard conditions of measurement.
• Current at the point of maximum power (Imp):  is the current produced when the power is maximum, under standard conditions of measurement.
• Voltage at the point of maximum power (Vmp):  is the voltage produced when the power is maximum, under standard conditions of measurement.
• Efficiency (%):  this parameter defines the conversion efficiency (ƞ), the amount of power radiation incident on the panel that is capable of becoming electrical power.

### Performance or efficiency = Wp / Wr

Where Wr is the power of radiation incident on the solar panel.

• Tolerance (%):  in the manufacturing process not all solar panels are identical, they present a small dispersion. In general, manufacturers guarantee that the power of the P * module is within a band; 63%, 65, 0 + 3%.

Also ideally, look for panels with only positive tolerances, so the manufacturer guarantees at least the power of the panel declared in the data sheet.

• TONC (ºC), nominal operating temperature of the cell:  the temperature reached by the cells when subjected to an irradiance of 800W / m2, ambient temperature of 20ºC, a wind speed of 1m / s and a spectral distribution AM 1 ,5.

## Electrical characteristics of solar panels:

### Other important features to consider:

1. Effect of illumination intensity (Irradiance)

The current supplied by a panel is proportional to the intensity of the radiation and the cell surface of the panel. Let’s see a graph in different irradiances at constant temperature, to show how the intensity varies,  to higher incident radiation greater intensity .

• The panels present losses due to an increase in the operating temperature , as a rule they oscillate by every 10ºC of increase by 4%.

Thus the tension provided by a panel varies depending on the temperature. The higher the temperature, the lower the voltage. In the graph that we show below, you can see:

So in the technical sheets we will give the variation in the maximum power (Pmax). Also open circuit voltage (Voc) and short circuit current (Isc) with temperature.

## Solar panels; types and specifications

Choosing between  different solar panels  is not the easiest subject, but we will try to help you more. You can probably continue on the basis of the explanation below. Do you prefer direct advice from one of our advisors? That is, of course, also possible; Free and without obligation.

## Important specifications of a solar panel.

There are many different producers around the world that offer solar panels. Unfortunately, one producer is not the other. The solar panels are also all different. Below you will find a series of specifications and factors that are important when buying solar panels.

### Choose a good manufacturer

When choosing a solar panel, it is very important to choose a specific manufacturer. In the market there are companies (especially Chinese) that want to make money quickly and, therefore, offer low prices. If such a company collapses, it often can not claim the factory warranty.

Therefore, we have selected a series of matches in which we believe. You also have a 10-year manufacturer’s warranty.

### Maximum peak watts

Manufacturers declare the capacity of a solar panel at the maximum watt peak (Wp). This does not mean that the performance is equal to the Watt peak number. This has to do with the number of factors, such as the placement of the panels, but also the number of hours of sunshine. Our experience shows that you generate between 80% and 95% in kWhs compared to the total number of maximum watts.

An average solar panel provides approximately 250 to 260 watts peak. We deliver solar panels with an even greater capacity. We have solar panels in our range with a peak of 320 watts! Then you need fewer panels to generate the same power.

### Module efficiency

The efficiency module indicates how much light energy can be converted into electricity by solar panels. In addition to the efficiency of the module, the efficiency of the cell is also often used. A solar panel consists of several solar cells. The higher the efficiency of the module or cell, the greater the efficiency that a solar panel provides.

### Approvals and certificates

Approvals provide guidance when choosing a good and reliable product. They also help you choose the best product for solar panels. For example, the CE mark must appear on the solar panels, otherwise they can not be sold in the Netherlands. The CE mark is a European brand that the product complies with European legislation.