How Do Solar Panels Work?
Solar panels can also be referred to as Photovoltaic (PV) modules. They are able to directly convert sunlight into electricity by using crucial materials that transformed the world [1] called “Semiconductors”.
When it comes to electricity, there are two main types of materials: Conductive materials (Metals such as bronze, iron, etc) and Non-conductive materials (Insulators such as ceramics, glasses, rubbers, etc). Semiconductors are crystal materials which possess both electrical conductivity and resistivity characteristics (conducting when temperature goes up).
Semiconductors can be doped with Boron (B), Aluminium (Al) to form P-type semiconductors which possess holes (positive), or Phosphorus (P), Arsenic (As), Antimony (Sb) to form N-type semiconductors which possess free electrons (negative). A combination of a P-type and a N-type semiconductor forms a vital concept, a PN junction where a P-type semiconductor is able to take free electrons from a N-type semiconductor in a non-directional way. The depletion region is formed after that in the centre of a PN junction, and it basically means that a voltage source is created to allow the free electrons to move in a certain direction.
When placing a solar cell under sunlight, free electrons in the N-type semiconductor will be knocked by particles of light or photons and migrate to the P-type semiconductor if the load is connected.
A PN junction forms a cell with a voltage of around 0.6V and they are connected in parallel or series to increase current and voltage to a practical value, forming a solar panel.
Types of Solar Panels
Recently, three main types of solar panels commonly known in the solar industry are monocrystalline (single-crystalline cells), polycrystalline (multi-crystalline cells) and thin-film.
| Solar Panel Type | Manufacturing process | Advantages | Disadvantages |
| Monocrystalline | Purest silicons -> Cylindrical ingots -> Doped materials: Single silicon crystal is used -> Wafers -> Solar cells -> Solar panels | Higher efficiency and performance | Higher costs |
| Polycrystalline | Purest silicons -> Cylindrical ingots -> Doped materials: Multiple silicon crystals are used -> Wafers -> Solar cells -> Solar panels | Lower costs | Lower efficiency and performance |
| Thin-film | Reams of aluminium foil -> aluminum substrate -> CdS and ZnO layers -> Solar cells -> Solar panels | Lower costs
Portable and flexible |
Lower efficiency and performance |
At GreenElec, we always choose to install tier 1 solar panels with monocrystalline technology; hence, the highest efficiency including: LG and SunPower solar panels. Besides, we also supply some other tier 1 solar panels with affordable costs such as: QCELL, Canadian, Jinko, Trina solar panels.
Recommendation of solar panels for particular sites
1. No shading on the roof
The best option is Hanwha Q Cells solar panels due to their price to quality ratio with fairly high efficiency. Passivated Emitter Rear Contact (PERC) technology is developed by Hanwha Q Cells under the name of Q.ANTUM technology [3], which allows the solar panels to capture more energy than conventional solar panels. The solar panels are engineered in Germany and have an office in Sydney which provides customers more after sales service support. Q Cells include a 25 year limited warranty for power output of the solar panels.
More expensive solar panels but more efficient and have a better reputation are LG solar panels with the same warranty period of 25 year.
2. Shading on the roof
The best option is SunPower solar panels due to SunPower’s solution to overcome shading effects [2]. SunPower solar panels are one of the most efficient in the industry. SunPower Performance panels are designed to allow energy flowing in independent and parallel rows, which brings the overall efficiency of the solar panels up compared to other competitors. At GreenElec, we offer many solutions to handle shading effects including utilizing SunPower solar panels along with module level power electronics (MLPEs) such as SolarEdge power optimizers or Enphase microinverters.
Reference
[1] https://www.bbc.com/future/bespoke/made-on-earth/how-the-chip-changed-everything/
[2] https://sunpower.maxeon.com/au/blog/shade-happens
[3] https://www.q-cells.com/au/main.html
Author: Hieu Uong
Electrical Designer & Estimator
GreenElec
