There are two types of solar panels: thermal and photovoltaic. 

Thermal solar panels concentrate sunlight to produce heat. Photovoltaic (PV) solar panels capture energy from the sun and convert it into electricity.

Solar thermal panels, also known as solar thermal collectors or solar water heaters, are devices that use sunlight to heat water or other fluids for various applications. Unlike photovoltaic (PV) panels that convert sunlight directly into electricity, solar thermal panels harness the sun's energy to generate heat.

Photovoltaic (PV) solar panels are a clean, renewable source of energy that uses solar radiation to produce electricity. Solar panels and photovoltaic systems are synonymous. If several solar cells are electrically connected with each other within a supporting structure, a photovoltaic module is made.

Monocrystalline and polycrystalline solar panels are the two most common types of solar PV modules. Both work using photovoltaic cells made of silicon and the same material used in chips for electronic gadgets. The only difference between both two is configuration of the silicon.

Monocrystalline solar panels: Monocrystalline refers to a material or structure consisting of a single crystal. In the context of solar panels, monocrystalline solar panels are made from a single crystal structure of silicon.

Polycrystalline solar panels: Polycrystalline refers to a material or structure composed of multiple crystals. In the context of solar panels, polycrystalline solar panels are made from multiple silicon crystals.

Both types of solar panels have the same purpose: converting sunlight into electricity.

Key Difference between monocrystalline or polycrystalline

The main differences between monocrystalline and polycrystalline solar panels lie in their manufacturing process, efficiency, and appearance.

• Manufacturing Process:
  Monocrystalline solar panels are made from a single crystal structure of silicon.
  Polycrystalline solar panels are made from multiple silicon crystals.
   
• Efficiency:
  Monocrystalline panels tend to have higher efficiency compared to polycrystalline panels. The uniform crystal structure of monocrystalline panels allows for more efficient electron flow, resulting in a higher conversion rate of sunlight into electricity.
  Polycrystalline panels have slightly lower efficiency compared to monocrystalline panels. The presence of multiple crystals and grain boundaries in polycrystalline panels can cause some electron recombination, reducing their overall efficiency.
   
• Appearance:
  Monocrystalline panels have a uniform, sleek, and typically black or dark blue appearance.
  Polycrystalline panels have a textured or "grainy" appearance due to the presence of multiple crystals.
   
• Cost:
  Monocrystalline panels are generally more expensive to produce due to the higher purity of the silicon and the more complex manufacturing process involved in creating a single crystal structure.
  Polycrystalline panels are typically more cost-effective to produce since the silicon melting and solidification process allows for higher throughput and lower production costs.
   

It's important to note that the differences in efficiency between monocrystalline and polycrystalline panels are relatively small, and both types can effectively generate electricity from sunlight. The choice between the two often comes down to personal preferences, project requirements, and budget considerations.