Solar Panels – Thin is in!
Wider acceptance of solar energy has led to many technological advances in the solar industry with the aim to make the panels compact, lighter, long lasting, cost effective and overall, more efficient. Solar panel designs have gone through a sea change since the time they were invented. The latest design change making news is the introduction of thin solar film panels. However, thin solar panels require a bigger space for installation and may be better suited for commercial applications rather than residential.
Introducing thin film solar panels
A thin-film solar panel consists of thinner layers of photovoltaic materials that are placed on a substrate. They have several light absorbing layers and believe it or not, are 300 times smaller than a conventional solar panel. The size of the photovoltaic cells used along with built-in semiconductors makes these solar panels light in weight.
Types of thin solar panels
They vary based on the substrate used in manufacturing them and mainly four types of substrates are used in making thin solar panels.
Cadmium telluride (CdTe): This is the most common type of substrate used in the making of thin-film solar panels and enjoys a fifty per cent market share. Cadmium Telluride is efficient in catching sunlight and converting it into energy, and is said to have 9 – 11 per cent efficiency. A downside of CdTE thin film panels however is the presence of a huge amount of Cadmium, a harmful element. Another drawback is, it is not commonly found, making mass production difficult.
Amorphous silicon (a-Si): Second in rank in terms of usage and popularity, solar cells made with amorphous silicon substrate, which is a non-crystalline silicon, don’t have a great efficiency range and are best used for small size operations. They are easier to produce than mono or polycrystalline solar cells. The A-Si thin film panels are considered one of the most environmentally friendly photovoltaic technology.
Copper indium gallium selenide (CIGS): These solar panels made with a copper indium gallium selenide substrate contain cadmium too but are less toxic than those found it CdTe cells. Layers of Copper, Indium, Gallium, and Selenide are placed on top of one another, which form a strong semiconductor to convert sunlight into energy. This innovation saw the light of day in Germany in 2011 and subsequently US and China have also begun manufacturing the CIGS thin-film solar panels. They have an efficiency of 10-12 per cent.
Gallium arsenide (GaAs): These thin solar film panels, which use gallium arsenide, have emerged as the most efficient of all the other options available in the market. They have an efficiency level of 28.8 per cent but are expensive. So, they are used more in applications where PV energy is needed like building space crafts.
Thin-Film Solar Panels Pros and Cons
Pros:
- They are lightweight – each layer of the panel is only 1 micron thick
- The use of silicon makes them eco-friendly
- They are cheaper and easier to install
- They perform well even in high temperatures
- Being enveloped in high-quality glass layers makes them resistant to moisture and so work efficiently in tropical climates
Cons:
- The use of cadmium in the thin-film panels is not necessarily good for the environment
- Not very suitable for residential use
- Require larger space to install than conventional panels
- Require specific material for installation
- Have a lifespan of only 10-20 years
All said and done, thin-film solar films are the best things to have happened to the solar industry in terms of innovation and technology and are certainly here to stay!
