Solar Panels
They come in different sizes and colours with different solar cell types from various manufactures. Sunlight reaches our solar panel in the form of photons, small energetic particles/waves. These photons carry energy in the form of light, heat, and radiation, but it’s the light energy that a solar cell uses.
There is an anti-reflective coating on the front of a solar panel that protects the cell inside while allowing through as much light as possible. Glass is an excellent material for antireflective coatings, so solar panels are coated in strengthen laminated glass.
The inside of a solar cell contains a semiconductor material. Silicon is the semiconductor we use in home solar panels. A semiconductor is a material that is sometimes a good conductor of electricity and sometimes not. This changing conductivity is what we use to generate electricity.
Sizes
Solar panels for grid-tied systems come in two main sizes, depending on the number of solar cells they are made from. 60 cell panels are about 1.6m tall and 1m wide, 72 cell panels area about 2m tall and 1m.
Larger panels are not better because they are bigger, they will generate the same energy on the same area of roof as smaller panels. i.e. the performance of 5 X 72 cells panels will be identical to 6 X 60 cell ones with the same energy and the same roof area. The choice is about which size of panel will best fit the available roof space.
Cell Types
A solar panel is made using solar cells. Each cell is about 6 inches, 125mm, square. The cells are made using one of two different materials, monocrystalline or polycrystalline. Polycrystalline is slightly cheaper but is less efficient so a solar panel made with monocrystalline cells will generate more energy than one made using polycrystalline cells, but will be more expensive. Monocrystalline cells are also darker and so best used when you want a black back sheet for the best looking solar panels.
Manufacturers
With major world brands like Canadian Solar, JA Solar and others you can be confident they will be around for the long term. Other smaller companies may not survive in the very competitive solar market. Often brand names you will see are not the actual manufacturer so it is important to find out who actually makes the panel and how secure they are as a business.
Between them the Top 7 solar panel manufacturers in the world made over 50% of the total panels made world-wide in 2017 and these form what is known as the Silicon Module Super League. It is highly recommended that you choose one of these brands to give you best the chance of long term reliability and performance.
