In order to choose the right photovoltaic system, you first need to estimate your electricity consumption and decide how much of that energy you would like to generate from the PV system.
You need to see how much roof space is available as well as your budget.
With so many products available on the market, shopping for PV panels may be quite a daunting task, especially if you are not sure what you need to look for.
All panels look the same to the untrained eye, but in actual fact they are very different. Brand name and price should not be the only deciding factors. Here are some points that will help you recognise and buy a good quality PV system:
Ask for international PV panel certifications such as EN61215 and EN61730. Good quality PV panels would also carry the EN61701 certification for resistance to salt mist corrosion. This is vital for PV systems that are installed close to the sea.
A quality PV panel will be manufactured and assembled mechanically or by robots. This gives a 100 per cent conductivity precision to the panel which can never be obtained with hand-assembled PV panels.
Hand-soldered cells typically create more resistance, making it slightly more difficult for the power being produced in the cell to flow through the panel, which will obviously result in fewer units produced. You will be able to notice the difference between the two by looking at the alignment and soldering of the PV cells.
Most would think hot summer months are better for PV panels. However, in many cases, it is actually the contrary. Crystalline panels lose their efficiency on hot days. Efficiency loss starts when the temperature exceeds 25°C.
You could have the most efficient panel in the world. However, as soon as temperatures begin to exceed 25°C, this efficiency starts dropping as the temperature gets higher. It is therefore important to check that the panel you are buying is a panel that can resist high temperatures.
Many panels on the market are not made to cater for such heat as they are meant to be installed in cooler places. This is why a lot of Maltese people who have installed PV panels are not satisfied with the production of their system.
It is also beneficial to buy a panel from a company that specialises only in PV panels or alternative energy products. This gives you 100 per cent assurance that these people are specialists in the field and that all their energy is being invested in their products.
One of the most important things to look out for is warranty. It is important to understand the difference between the guarantee on the product and parts and the guarantee on the performance of the system.
A standard warranty on PV panels is five years on the product and 25 years on the performance of the panels.
Once a product warranty has expired, it is important to note that a claim against loss of performance within the stipulated 25-year bracket may be not claimed if the issue is related to a defect in the product material or parts.
High quality panels will carry 10 to 12 years of product warranty.
The design of a system is just as important as the quality of the product. You can have the ‘Rolls Royce’ of the PV panel market, but if poorly designed, performance will be affected. Ensure a qualified engineer designs your system.
Make sure your system has a direct current isolator and an alternating current isolator. This is critical for your safety as well as anyone working on the PV system in the future. A high quality, efficient inverter must be carefully selected in order to have efficient power output. If the inverter is not well matched, the power output will be affected.
A strong PV mounting structure is vital for windy days. Malta is prone to strong winds and powerful gusts even in summer.
Installing a PV system is an investment, so it needs to give you back the best returns as quickly as possible. It is in your interest to ensure that you purchase not only the best panels for your energy needs but that the rest of the equipment and the installation is the best in terms of quality and safety.
Ms Schembri is director, Electrofix.