There are 3 types of technology utilised in the solar panels available on the market today, these are monocrystaline, polycrystalline, and thin film amorphous.
In a Nutshell:
Monocrystaline and Polycrystaline are both pretty much the same for all intents and purposes and are both the most efficient in terms of power generated per area of panels installed. 95% of quotes you’ll receive will be for ‘Mono’ or ‘Poly’ panels as they’re known in the industry.
Choosing a good quality panel from a reputable manufacturer is much more important than deciding on whether to go ‘Mono’ or ‘Poly’.
Thin film is a totally different technology which is much less efficient and therefore uses much more roof space. Its one advantage is that it performs better in low light conditions and when there is partial shading of the system.
This is the oldest and most developed of the three technologies. Monocrystalline panels as the name suggests are created from a single continuous crystal structure.
A Monocrystalline panel can be identified from the solar cells which all appear as a single flat colour.
They are made through the Czochralski method where a silicon crystal ‘seed’ is placed in a vat of molten silicon. The seed is then slowly drawn up with the molten silicon forming a solid crystal structure around the seed. The rod of solid crystal silicon that is formed is then finely sliced and shaped into the solar cells you see making up solar panels.
cells you see making up solar panels.
To date, of all the commercially available technologies, Monocrystalline is the most efficient.
- Between 14-15% efficiency.
- More expense though less common panels can reach 20% efficiency.
- They are very susceptible to shading effects and quickly lose output with even small amounts of shading.
- Generally occupy the least space for the same amount of power than other technologies.
Polycrystalline or Multicrystalline are a newer technology and vary in the manufacturing process.
Polycrystalline also start as a silicon crystal ‘seed’ placed in a vat of molten silicon. However, rather than draw the silicon crystal seed up as with Monocrystalline the vat of silicon is simply allowed to cool. This is what forms the distinctive edges and grains in the solar cell.
Polycrystalline cells were previously thought to be inferior to Monocrystalline because they were slightly less efficient, however, because of the cheaper method by which they can be produced coupled with only slightly lower efficiencies.
Polycrystalline are now about equivalent in performance to Monocrystalline cells.
- Between 13-14% efficiency.
- Equally susceptible to shading as Monocrystalline due to the way the cells are connected
- Perform slightly better than Monocrystalline in low light
- Occupy marginally more space than Monocrystalline for the same power output
Overview and Appearance
Thin film panels are a totally different technology to Mono and Poly crystalline panels. They are a new technology compared to Mono and Polycrystalline cells and would not be considered a mature technology as vast improvements in this technology are expected in the next 10 years.
A thin film panel can be identified as having a solid black appearance. They may or may not have a frame, if the panel has no frame it is a thin film panel.
Thin film panels are made by depositing a photovoltaic substance onto a solid surface like glass. The photovoltaic substance that is used varies and multiple combinations of substances have successfully and commercially been used. Examples of the most common photovoltaic substances used are:
- Amorphous Silicon
- Cadmium Telluride (CdTe)
- Copper indium gallium selenide (CGIS)
- Dye-sensitized solar cell (DSC)
Each of the above are known as different panel ‘types’ but all fall under the umbrella of being a Thin Film panel.
Thin film cells have got a reputation as being the ‘worst’ of the solar panel technologies because they have the lowest efficiency. However, this is only because they have a lower power efficiency which only means they require the most space for the same amount of power. Since they are becoming the cheapest panels to produce because of the low material costs for thin film they are quickly becoming the more economically efficient panel types.
- Typically commercial panels sit between 6-9% efficiency
- Far less affected by shading than Mono or Polycrystalline panels
- More efficient in low light conditions.
- Performance and cost improving the most rapidly
- Likely to become the dominant technology in the next 10 years.
Mono and Polycrystalline panels have had time to mature over the much younger thin film technology and as such are currently the most dominant technology.
In areas where space is an issue, Mono and Polycrystalline technologies have been best since they are able to get the highest power output for the smallest space.
If shading is an issue and space isn’t at a premium, thin film might be the best option.
If in doubt, get a few quote and have the companies compare the returns on investment across the different technologies, also use the Energy Saving Trust Solar Savings Calculator to get a better understanding of how installing solar relates to your specific circumstances.