In these times of expensive energy prices for fuel oil, gasoline and gas, more and more people are switching to  solar panels.

In the following images you will find more information about solar panels, you just have to click on them and access all the information



 Solar panels are quite expensive to buy, but after a few years it recovers the investment, especially now that prices have dropped considerably. 

Another great advantage is that a solar panel does not pollute and is a great advantage if we want to reduce CO2 emissions to keep the land habitable for our children and future generations.

What are solar panels?

Solar panels are devices designed to generate electricity or hot water and heating according to the type of solar panels used.

Sometimes people get confused when we talk about solar panels, we usually associate the term “solar panels” with photovoltaic solar panels, but this is not always the case.

 What are solar panels for?

There are two types of solar panels that fulfill completely different functions:

  • Photovoltaic solar panels : destined to produce electricity using the sun’s rays.
  • The solar thermal panels : destined to produce hot water for sanitary use and heating of the home.

Solar panels that are What is a solar panel and how does it work?

-A photovoltaic solar panel is a collection of solar cells that are responsible for transforming sunlight into electricity through the photovoltaic effect.

  • The thermal solar panels absorb sunlight through the solar collectors and convert it into heat, which heats a liquid flowing into a tank, heating the water containing.

Solar panels as they work

The operation of  solar panels  is based on the photovoltaic effect, which occurs when, on semiconductor materials conveniently treated, the solar radiation affects electricity producing as I mentioned above.

At the moment when it is exposed to solar radiation, the  different contents in the light transmit their energy to the electrons  of the semiconductor materials that, then, can break the potential barrier of the PN junction, and thus leave the semiconductor through of an external circuit.

These  photovoltaic cells  are combined in many different ways to achieve both the desired voltage and power and thus be able to get the solar energy is converted into energy to be able to consume.

Not surprisingly, we understand by photovoltaic cell the smallest semiconductor material with PN junction and also with the capacity to produce electricity.

We should not forget at this point that the photovoltaic panel is referred to as the set of cells on the appropriate support and which have the coatings that protect them from atmospheric agents.

In another article we explain in detail the different  types of solar panels  that exist. Do not miss it if you want to know the different types of panels that we can find on the market today.

What voltage can a solar panel produce?

The 24V solar panels work in the same way as the 12V insulated panels but at a 24V voltage. They are formed by 72 cells with which their size is greater and generate powers ranging from 150 to 195 watts  (W).

Prices of solar panels

The prices of solar panels in a summary.

The prices of solar panels depend on your home and energy consumption. Below you will find a summary of the average electricity consumption for different households per year, the required number of Wp, the required number of panels and the average costs and benefits.

# house peopleAvg choose the annual consumption in kWh.# Wp to provide (kWh / 0.85)# panels (250 Wp per panel)Average price of solar panels (including inverter and installation).Avgahorro per year
one2,3002,700eleven€ 5.100€ 527
two3,4004.00016€ 7,600€ 782
34.1004,800twenty€ 9,100€ 938
44,6005,40022€ 10,200€ 1,055
55,3006,20025€ 11,700€ 1,212
65,4006.35026€ 12,000€ 1,241

Do you have a large home with, say, 5 people? Then you can take into account the following factors:

  • Average energy consumption: 5,300 kWh per year.
  • Solar panels of energy: approximately 6,000 Wp (for example, 20 solar panels of 300 Wp)
  • Price of solar panels: approximately € 11,300, including inverter and installation.

Of course, it is also important to know how many solar panels you can place on your roof. The size of an average solar panel is approximately 1.5 m2. You can place up to 20 solar panels on an average sloped roof.

Of course, if you do not have enough space, you can also choose to install fewer solar panels and only partially meet your energy needs. With this you can still achieve a great benefit.

What are the types of photovoltaic solar panels that exist?

  • monocrystalline solar panel
  • monocrystalline photovoltaic panel
  • Polycrystalline photovoltaic panels

Images of photovoltaic solar panels. 

Photovoltaic solar panels: information on solar panels.

What is a photovoltaic solar panel?

The  solar panels power per square meter  are simply a panel that converts solar energy into electricity. However, a solar panel is a bit more complex than this definition.

The photovoltaic cells are placed on the panel to convert solar energy into electricity. The most important part of these cells is a piece of semiconductor material. 

When sunlight falls on the solar cell, the energy is released in the form of electrons. The solar panel supplies direct voltage.

When the panel is connected to an inverter, alternating current can be obtained. This energy can be used directly by the connected devices.

In practice, standard panels with a size of approximately 1.6 square meters are normally used.


Types of solar cells 

The solar cells that are placed on the solar panels are made of silicone in most cases. Silicon consists of two layers, an electric current that flows between these two layers under the influence of light.

The way in which this silicon is processed determines how sunlight or daylight is processed and, therefore, the quality of a solar cell. 

When buying the correct panel, therefore, it is important to delve into the type of solar cell. There are three  types of solar cells  :

  • Monocrystalline  : higher price, but the best performance.
  • Polycrystalline  : affordable price and quite high efficiency
  • Thin film : lower price, but lower profitability.

Size of photovoltaic solar panels, what size are they?

The size of a solar panel is a factor that determines how many solar panels you can place on your roof. The amount of solar panels that you can place on your roof depends, on the one hand, on the size of the solar panels and, on the other hand, on the situation.

Solar panels with solar cells generally have fixed dimensions that depend on the  capacity  of the solar panels.


1) Standard solar panels:  dimensions 165 x 99 cm. This size is generally used for solar panels with a capacity between 245 and 285 WP.

2)  Large solar panels: size 195 x 99 cm. This size is generally used for solar panels with a capacity greater than or equal to approximately 300WP.

3) CIS solar panels: generally with smaller dimensions. The best-selling Solar Frontier has a size of 126 x 100 cm.

4 ) Small solar panels : with dimensions of 158 x 81 cm they are also on the market, but they are almost never used.

The dimensions of the thin film solar panels  are vastly different and different according to the manufacturer. The market leader, Solar Frontier, uses a dimension of 126 x 100 cm for its 170WP panel.

 However, the question is how long these panels will be available. Solar Frontier has indicated that it will stop distribution in Europe.

With the dimensions of the solar panels, you can now make your own installation plan. In this way, you can see if you can better position the solar panels horizontally (horizontally) or vertically (vertical). An area called

No-Go also applies to sloped roofs: a space of approximately 20 centimeters between the solar panels and the eaves. Along with the dimensions of solar panels, you can now determine how many solar panels you can place on your roof.

For flat roofs, the flat roof of the No-Go zone is applied, caused by regulations and wind load. We also have the useful tool to calculate the distance between the solar panels and the flat roof.

Advantages and disadvantages of photovoltaic solar panels. 

Before buying solar panels, it may be good to know more about the advantages and disadvantages of solar panels. Many people often wonder why they should invest in solar panels.

This is, of course, a disadvantage, fortunately, the return of the solar panels is high. Therefore, a solar panel has advantages in terms of finances, the environment and the value of your home.

Why solar panels?

Solar panels are increasingly seen in the Dutch street scene. There is a lot involved in the purchase of solar panels.

Your interest in solar panels has clearly awakened, but there may be even more advantages of solar panels than you already know:

  • Contribute to the production of sustainable energy.

    More and more people are aware that it is important that we use our energy in a different way. The solar panels are ideal to make your contribution to this. For most, this is the most important reason to buy solar panels.

  • The independence of energy suppliers.

    Because it can generate its own energy, it no longer depends on the energy providers. This also means that it no longer depends on price fluctuations and, therefore, determines the  price  of your energy.

What are the advantages of solar panels?


  • environmental friendly
  • Form of high quality energy.
  • Low maintenance
  • There is enough solar radiation everywhere.
  • Modular and, therefore, usable from very small to very large capacities.
  • Sustainable installation with safe operation.
  • Short time of manufacture and installation.

What are the disadvantages of solar panels?


  • High cost price, especially for systems connected to the network.
  • Low energy density, large surface area required per unit of energy efficiency
  • Variable energy supply from the sun, energy storage or reserve capacity is required.

What is the useful life of a photovoltaic solar panel?

How long can a solar panel last? On average, solar panels last around 40 years. Manufacturers grant an average warranty of 25 years for the capacity of solar panels, but by selecting the right solar panels, you can also benefit from your solar panels for much longer than the warranty.

Lifetime and maintenance of solar panels.

Installers will tell you that their solar panels have a lifespan of at least 25 years. But is that really true?


If you buy a good brand of solar panels, they will easily reach the useful life of 25 years. But if you buy a lesser known brand, it is very likely that you will not achieve this life.

Good installation and good monitoring are of great importance in this. Below you can read what you should pay attention to. So you can enjoy the power of the sun year after year.

We do this based on the 3 most important parts of your system:

  • Solar panels
  • Investor
  • Installation and assembly

25 years of production guarantee on solar panels.

Most producers give a production guarantee of 80% after 25 years. But what does that mean?

The guarantee means that you can assume that you will continue working after 25 years. You can also assume that your capital after 25 years is more than 80% of the original capital.

These are also real guarantees, which are feasible for most solar panels in practice.


The solar panels are inclined and, in principle, clean well with the rain that falls on them. However, it does not hurt to clean once a year, like cleaning the windows.

A good installation

The installation is perhaps what can go wrong. Therefore, it is important that the installation is carried out by an expert and certified installer. The following components are essential here:

  • Good wiring and connections.
  • Solar panels do not get shade.
  • A robust installation on your roof.

Often, any problem with the installation happens during the first year and, therefore, they are covered by the total guarantee of the system.

Lifetime of the inverter.

The investor is usually the part that first breaks. The average of an investor is 10 to 15 years. There is a possibility that you may have to replace the inverter with a new one within 25 years. It is also advisable to invest in a good investor of a known brand.

Fortunately, the costs of a good investor are limited in relation to the total costs of your system and this additional investment can be monitored.

Measure your performance

How do you know if your system is still working correctly? You can measure this with your performance meter.

The quote usually indicates the expected return in kWh in the first year. It is important that your system achieve the income promised in the first year. If this is not the case, ring the doorbell of your installer as soon as possible.

In subsequent years you can track daily, monthly or yearly income. If strange deviations occur, it is very likely that there is a problem with your system. Then have your installer see your system.


Choose a  good brand of solar panels  , then this system can easily reach 25 years and probably much more. There is a possibility that you replace the inverter once.

It is also advisable to properly measure the production. Then you see what performance is and if something is wrong. While doing so, you can enjoy the power that the sun gives you year after year.

Solar panels for houses.

Solar panels for houses are an excellent option to generate your own electricity and thus help the environment and save money.

If you want to install solar panels in your home, you should know the information that we provide below.

Read more :

Best brand of solar panels

Prices of solar panels.

Are you looking for solar panel prices? What are the different types and which one best suits your needs and your budget? Continue reading this article to find all the answers to your questions.

The prices of solar panels.

Or a system of solar panels does not have more prohibitive costs but, on the contrary, implies a reduced and accessible expense.

 The cost of a solar panel system depends on the number of people living in the house, the annual energy consumption and the amount of solar panels that will be installed. 

See the following table to find the indicative cost of installing solar panels in your home.

Number of people in the house.Annual electricity consumptionPrice of solar panels
2 people3000 kWh€ 2,000 – € 4,000
3 people3500 kWh€ 3,500 – € 8,800
4 people4000 kWh€ 8,000 – € 9,000
5 people4500 kWh€ 9,000 – € 10,200
6 persons5000 kWh€ 10,000 – € 11,000

How much do solar panels cost for your home?

Installing a solar panel system will save you on your bill; In most cases, however, it is also possible to save on the cost of solar panels.

 Since the cost of solar panels can vary from one company to another, the best way to find the best offer is to compare several quotes. This will guarantee the best value for money. 

You will receive the offers and, when you compare them, you can save up to 40% on the cost of your new plant. Saving money has never been so easy and fast! A new car, a PC, a good trip … have you already thought about how to use the money saved?



What solution to choose?

Assuming you have an average Italian family of two adults and one child, you will have an average electricity consumption of 3500 kWh per year. 

However, since the sun does not always shine, the average efficiency of the solar panels is not 100%, but it is reduced to 85%. 

For this reason, it will be necessary to install solar panels that provide more capacity than the actual electricity consumption. Therefore, in the case of a consumption of 3500 kWh, it will be necessary to install solar panels of 4100 Wp (the abbreviation Wp means peak watts and does not express the standard power and the maximum power supplied by a module under optimal conditions).

 The average price is € 8800 and the investment will be recovered in approximately 10 years with an annual saving of € 875.

In addition, since the solar panels will last at least 25 years, you will benefit from the aforementioned savings for at least 15 years, saving at least another € 13,000.

An important element to consider when buying your solar panels is the amount of square meters available on the roof. 

As a solar panel has an average of 1.5 square meters, in the previous case there should be 27 square meters available (18 panels x 1.5 square meters / panel).

 Also, do not worry if you do not have enough space available: you can install fewer solar panels and only meet one part instead of the total energy consumption.

On the other hand, how much can a thermal solar system cost   , not for the production of energy, but for domestic hot water? The cost, on average, is around 3000 – 9000 €.

The types of solar panels and their prices.

The price of solar panels depends, of course, also on the type of solar panel chosen. For this reason, before continuing with the purchase, it is important to carefully evaluate the different characteristics of the possible alternatives. There are three different types of solar panels, in particular:

  • monocrystalline silicon solar cells;
  • polycrystalline silicon solar cells;
  • Thin film solar cells.



The monocrystalline and polycrystalline solar panels are derived, as the name suggests, from glass. Monocrystallines have a higher efficiency, but they are also a little more expensive than polycrystalline ones. 

However, technological advances mean that these differences are getting smaller and, consequently, both types of panels are an excellent option.

Thin film solar panels, on the other hand, that have a lower yield, cost approximately 20% less. Flexibility is the characteristic that distinguishes this type of solar panels.

The cost of the inverter for solar panels.

The converter (or  photovoltaic inverter  ) has the purpose of converting the continuous electrical current produced by the modules into alternating electric current. 

As mentioned, its cost is included in that of the solar panels; however, since it has an average duration of 10/12 years, it is likely that it should be replaced at least once. 

The cost of a converter depends on its capacity and quality. The average price of a converter that offers power for solar panels with a capacity of 4000 to 6000 Wp is around € 1600.

BEST BRANDS OF SOLAR PANELS 2019 : Types of solar panels

The cost of installing the panels.

Do you wonder how to install solar panels on the roof of your house? Remember, first of all, that incorrect positioning or incorrect panel tilt can greatly affect panel performance.

 For this reason, it is essential to have a specialist who has all the knowledge, tools and experience necessary to place the solar panels correctly and safely. 

The installation cost is always included in the list price and represents 15%.

Thermal solar panels


What are thermal solar panels and why choose them?

They can also be called  solar collectors  and the main characteristic that distinguishes them in the photovoltaic market is that, by absorbing solar radiation, they can perform two fundamental functions to meet the main needs of a building:

  • heat water for the sanitary water system;
  • Provide the necessary heating or air conditioning inside.

How do thermal solar panels work?

Thermal solar panels consist of a  flat surface  or  a series of tubes  , in the type of vacuum, that contain a liquid that, with solar radiation, reaches a temperature that varies from 50 to 90 degrees.

The heat is transferred to the storage tank, where there is water, which is heated to be used.



(Diagram of operation of a solar thermal system with solar collectors, storage tank and integration with auxiliary heating.

Solar thermal panels guarantee an average water temperature of 38-45 ° C and can be used to heat the house, heat the water in the pool or water in the floor heating system.

In the summer period  , the solar thermal panels allow to guarantee an optimal fulfillment of the two functions of heating and domestic hot water, while in  the winter period  , although the efficiency of the panels allows the capture of solar radiation even on cloudy winter days. , it is not possible to use only the solar system, but it  must be integrated with a traditional system  , such as an instantaneous gas boiler.

Another solution to always have hot water available is to  insert an electric heater with a thermostat set at 40 degrees, to guarantee a certain autonomy and electrical independence.


What type of thermal solar system is better?

There are two types of solar thermal systems and their greater or lesser convenience is due to climatic factors, the positioning of the roof or the space in which the system will be installed. Here are some general rules:

  • Solar thermal systems with  natural circulation  are ideal for a family in northern Italy with 2-3 components, for a family in the south with 3-4 components or in the case where the solar system is installed on a flat roof or in an attic;
  • Solar thermal systems with  forced circulation  are ideal for a family of 3 or more people, with no restrictions on the location of the solar system or the tank.


Do thermal solar panels last longer than photovoltaic solar panels?

Solar thermal panels have  a superior  performance  of  strength and durability  compared to photovoltaic panels  .

It has been found that a solar thermal system  can last about twenty years  if it has been installed, placed and dimensioned according to the energy of the house in which it is located.

With routine maintenance and performance efficiency checks, a solar thermal system guarantees the optimal use of its thermal performance, understanding that its components are a case in their own right and could occur, that some parts, such as

Investors or other elements, have a greater need for extraordinary maintenance, during the normal life cycle indicated above.

In addition, do not forget that each solar thermal system  has a guarantee of at least 5 years  and, at the time of purchase, it is generally proposed an insurance policy for all risks, which often includes the cleaning of routine, annual or biennial.

How much does a solar thermal system cost?

The total cost of a solar thermal system  varies according to the useful area for the installation of the panels  : the more space there is available, the lower the price. A fair and indicative estimate of the price can be from 550 euros to 1500 per square meter.

In general, the purchase of a solar thermal system  is entitled to regional or municipal incentives  and presents  VAT at 10%  , compared to 20% of photovoltaic energy.

The  amortization times of the expenses  , being the lowest cost, vary from three to seven years maximum, in areas where the climate is more rigid.


Types of solar collectors.

There are two types of solar collectors, vacuum collectors and flat plate collectors.

Vacuum tube collector:


The  collectors of  vacuum  have little influence on outside temperatures and, therefore, can produce a lot of heat when it is cold outside.

A vacuum manifold consists of a series of vacuum glass tubes that are placed side by side. There is an absorbent inside the tubes.

This absorb absorbs solar radiation and is connected to a closed tube, which is called a heating tube. The liquid that releases its heat in the upper part of the water in the storage tank evaporates with solar irradiation.


Flat plate collector:



Several designs of this type of collector are possible, which facilitates their integration into the architecture. A flat plate collector consists of a shallow container.

This tray is constructed in turn from a fluid circuit filled with pipes, insulating material and a translucent cover plate.
How to achieve maximum efficiency with a solar thermal panel?
A solar thermal panel is not only respectful with the environment, but also reduces the energy bill.

After all, they are known for their high energy efficiency. With the help of a solar thermal panel, you can save up to 60 percent on your energy consumption to heat the water for sanitary purposes.

best brand of solar panels and their efficiency

 The  best brand of solar panels and their efficiency High efficiency, today, is considered a photovoltaic panel  that is above 19%. That is, 190W for each square meter installed. This, as you can already perceive, is very important for photovoltaic selfconsumption installations  , which are usually on rooftops where space is always limited and the more efficient the panel, the more power we can install.

And these would be the best solar panels of 2018 according to their efficiency:

Panel BrandModelMinimum efficiencyUnitary PowerSize (length x width)
SunpowerSPR-X22-37022.7%370W1,559 x 1,046 mm
SunpowerSPR-X22-36022.1%360W1,559 x 1,046 mm
SunpowerSPR-X21-34521.2%345W1,559 x 1,046 mm
LGLG360Q1C-A520.8%360W1,700 x 1,016 mm
LGLG355Q1C-A520.6%355W1,700 x 1,016 mm
AUOSunForte PM096B0020.6%335W1,559 x 1,046 mm
AUOSunForte PM096B0020.3%330W1,559 x 1,046 mm
SunpowerE20-32720.1%327W1,559 x 1,046 mm
SHARPNQ-R256A19.8%256W1,318 x 980 mm
PanasonicVBHN330SJ5319.7%330W1,590 x 1,053 mm
PanasonicVBHN325SJ5319.4%325W1,590 x 1,053 mm
SunpowerSPR-P19-40019.4%400W2,067 x 998 mm

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