Solar Photovoltaics

Solar Photovoltaics

Solar photovoltaics (Solar PV) is the process of capturing the energy from the sun and converting it into electricity. The energy produced does not contribute to climate change, produces no pollution, and is completely silent. Solar panels have no moving parts, so they are reliable and virtually maintenance free. There are no running costs, so once your system is installed the electricity doesn't cost you a penny.

It doesn´t require direct sunlight, so it works even in cloudy Britain.

How does the photovoltaic effect work?

When photons from light of a suitable wavelength hit a photovoltaic cell, usually made of silicon, they can transfer their energy to some of the electrons in the material. The electrons become free to conduct electric current by moving through the material. One side of a photovoltaic cell is positive and the other negative and with the respective connections made to each, a circuit is formed and the cells generate electricity.

Different types of panel :

There are three main types of panel widely available on the market today.

Monocrystaline

Monocrystalline are the most efficient and generally the most expensive type of solar panel.

They are manufactured using very pure silicon and a complicated process of crystal growth to produce a silicon rod. The silicon rod is then cut into thin slices (0.2mm – 0.4mm thick) which go on to from the individual cells that make up the solar panel.

Polycrystaline

Polycrystalline panels are marginally less efficient than their monocrystalline cousins. Accordingly they are also slightly cheaper.

Rather than a being made from a single crystal of silicon, large blocks of many crystals are grown and then sliced to create the individual solar cells. It is the grouping together of many silicon crystals in blocks that gives polycrystalline panels their distinctive ‘shattered glass’ appearance.

Amorphous

Amorphous panels are much cheaper than crystalline panels, but are less efficient and therefore need a greater area (typically double) to produce a similar output. Having said that, they do tend to out perform crystalline panels in low light levels, which is worthwhile knowing, particularly with UK weather!

They are not produced by slicing crystals but by depositing a thin layer of silicon on a suitable background such as metal or glass. This allows the production of the panels to be much more flexible – literally. Amorphous panels can be made into flexible modules (e.g. Sunlinq foldable panels) which can be rolled up or folded away or even made into long sheets of roofing material.

In addition to the main panels identified above there are also some Hybrid Solar Panels now being produced which combine monocrystalline and amorphous cells. This makes a panel that has the advantage of better all round performance in a wider range of light conditions but is hampered by it’s lack of flexibility and high price.

How can I benefit from Solar Energy?

Great, now I know all about solar panels, but how can I use them to benefit me and the environment? Well, there are loads of great ways to use solar power in our every day lives. Take a look at our easy to follow guide : Practical Solar Power.