Solar panels explained


Introduction to solar panels

The Algarve is the perfect location to take advantage of the financial, practical and ecological benefits associated with solar panels. It is rare to have a day when the sun is not visible, so you can make the most of a solar system all year round.

There is often confusion about the types of solar panels available, and their functions. These can be broadly divided into two types-panels that produce electricity (photovoltaic) and those that produce hot water (thermal solar). This article will explain the principles behind photovoltaic systems


Photovoltaic solar panels work by converting sunlight into electricity using the photoelectric effect. There are no moving parts within a photovoltaic solar panel. Apart from occasional cleaning and verification that the power inverters are operating correctly, there is no routine maintenance needed.

The electricity generated from the panels is DC (direct current) and an electronic device (known as in inverter) converts this to AC (alternating current) so that it can be used to power appliances in the home.

There are many different types of solar panels and inverters, and care should be taken when selecting the equipment for your home. Cheap panels have lower outputs, and are not constructed to the same standard that premium products have. Top of the range panels are now double sided, so they can produce electricity from sunlight reflected on the rear of the panel, thus increasing the output.

Inverters vary greatly in their quality, functionality and durability. The principle types of inverters are:

  • micro inverters. These are the simplest type and cheapest type of inverter. They generally have the capability to control fewer panels than the other types of inverter, so one micro inverter is needed for every group of panels. These inverters are often mounted directly to the rear of the solar panels, making for a simplified installation.
  • intelligent inverters. These are more complicated and have more advanced monitoring and control systems. They can control a larger amount of panels than a micro inverter. This type of inverter can (in some instances) be installed outside of a building, but in most cases will need to be installed where it is protected from the elements
  • hybrid inverters. These have the same functionality as intelligent inverters, but battery packs can also be added to store excess energy.

The vast majority of photovoltaic panels are fixed in place. When solar photovoltaic systems were first introduced in the Algarve there was a tendency to install tracking systems, that moved the panels to align in the most efficient way with the sun throughout the day. With the increase in performance from fixed panels, these tracking systems are no longer considered to be worthwhile.

When it comes to the way that the electricity is used, there are two options-simple and storage.

Simple photovoltaic

This system creates electricity and feeds it back into the electrical network with the home, thus reducing the amount of electricity that has to be supplied from the grid.

If you are producing more electricity than you need, this excess is imported to the grid and you do not receive any payment for this.

The key to maximising the efficiency of this system is to use as much of the electricity produced as possible. As an example, a swimming pool pump uses a significant amount of electricity, so if this is used during the day it will use the generated electricity, and maximise your saving.

A common error with this type of system is to install a system that has too many panels, and is constantly producing more electricity than you can use. It is better to have a smaller system, and use all of the electricity generated.

Storage photovoltaic

This system adds a method of storing the electricity generated (batteries of some form), so that it can be used when you are not generating electricity. It is the chosen system for off-grid properties, where there is no connection to the electrical network.

The costs and benefits of this type of system have to be carefully considered. The batteries add a significant cost, and you may not recoup the cost of the batteries within their useful lifetime. More panels will be needed to generate sufficient electricity, so your initial cost is much higher than for a simple system.

With the improvements in battery technology and control systems that ensure efficient use of electricity, the efficiency and financial benefits of these systems are becoming more attractive.

There is also a market for recycling used batteries (from electric cars as an example) that do not have 100% of their capacity but can be used for a domestic solar system. This is an interesting development, as the batteries have a reduced cost and are more than adequate for use as domestic power storage.

Other considerations

There are some other points that are important to consider when you are considering the installation of solar panels for your home in the Algarve.

Aesthetics-It is possible to install panels in a manner where they can operate efficiently, and not be an eyesore. Often the highest roof is the ideal position, as the panels will not be shaded, and are hidden from normal view.

It is also possible to install the panels within the garden, and away from the house. This is often a good solution where there is an area within the garden that is hidden.

Monitoring-whilst photovoltaic systems are generally “fit and forget”, it is important to check that they are working correctly from time to time. Power surges can damage the equipment, and cause failures.

There are many monitoring systems that allow you to check on the performance of your system remotely (via the internet). These range from simple systems that give basic information to very detailed software that provides a wealth of information.

Insurance-a solar system is a significant investment. Most home insurance policies include coverage for solar panels, but you should check to make sure that your policy does cover breakages and electrical surges.


The use of solar systems in the Algarve is, in our opinion, one of the best investments you can make, as long as the system is specified correctly to meet (and not exceed) your needs.

We encourage all of our clients to consider the use of photovoltaic solar systems to reduce their electricity consumption, and if you have any questions in relation to this please send us an email