Learn About Solar Panels
What you need to know about solar panels and PV technology.
Which solar panels are the best?
It can be a challenge to decide which solar panels are the best for your house, commercial/industrial building or solar power plant.
The more you know, the easier it is to make a decision. That is why we have listed some information on solar modules for you below.
How do solar panels work?
Photovoltaic panels are made of 8 major components:
1. Aluminium frame
2. Tempered cover glass
3. Encapsulation foil 1
4. Solar cells
5. Encapsulation foil 2
6. Back sheet
7. Junction box(es)
Solar photovoltaic cells convert sunlight into electrical energy. The solar energy is conducted via small metal strips (fingers) on the solar cells to wider metal strips (bus bars), which collect the energy and transport it to the junction box(es) on the back of the module. Via the junction box the solar panel is connected to other PV modules to form a string. A solar installation then usually consists of several strings.
What to consider when choosing solar panels?
Before deciding on PV panels, you should check these criteria:
✓ Trustworthiness of the brand
For a safe investment, you should choose a well-known and bankable (Tier 1) solar brand with a successful track record for many years.
✓ PV panel output and efficiency
The performance of a solar panel is stated in WP (watt peak, also referred to as wattage) and the efficiency in %. The higher the values, the better, but you should also consider the costs per Wp.
✓ Product guarantee
The product warranty is a guarantee on product material and workmanship, and covers your solar panels should you find issues caused by a manufacturing defect.
✓ Power output guarantee
The solar panel performance warranty provides a guarantee that your solar panels will perform at a certain level of efficiency after a specific number of years (e.g. during 25 years).
✓ Solar panel certificates
Solar modules are usually tested under extreme conditions (e.g. ammonia, salt mist, sand and PID resistance) and have the corresponding certificates.
How efficient is a solar panel?
The solar cell efficiency describes the proportion of energy in the form of sunlight that can be converted into electricity by the solar cell via photovoltaics.
Over the past 10 years the efficiency of average commercial wafer-based silicon panels has increased from about 15% to 20% and more. This means that a solar panel with 20% efficiency and an area of 1 m2 nowadays produces 200 kWh/year at Standard Test Conditions.
The Standard Test Conditions relate to a mean value of solar radiation. The actual output depends very much on the geographic installation of a solar module. The higher the sun is and the fewer clouds there are, the greater the output.
The module efficiency is specified on the data sheet of a solar panel.
But what are the most efficient solar panels in the world? High concentration multi-junction solar panels currently achieve an efficiency of up to 38.9% (up to 47.1% on cell level). This technology is still too costly for commercial use, but is already used e.g. for satellites.