A solar panel is a module of solar cells, commonly made with silicon. Treated silicon (or ‘doped’ silicon) can respond to light and emit a flow of electrons, as a direct current (DC) of electricity. There are two designs incorporating silicon into cells, crystalline and amorphous, or thin-layer. Crystalline versions of silicon can either be a single (mono) crystal, or multiple (poly) crystals.
Mono-crystalline cells are sliced from large cylindrical ‘ingots’ of silicon crystals, grown in controlled conditions. They generate the most electricity per unit area, but are the most expensive. The solar cells are recognisable square cells with ‘missing corners’ due to the manufacturing process.
Poly-crystalline are, instead, multiple slices of silicon, cut from smaller crystals made using molten silicon. These are locked together to form a solar cell.
The production is cheaper than single crystal cells, but they are slightly less efficient.
Amorphous solar panels comprise of thin layers of silicon deposited on backing (metal) sheets. They tend to be much more flexible and have been traditionally used in calculators or garden lamps. They are relatively cheap to manufacture but with as little as half the efficiency of crystalline models. The main advantage, however, is greatly increased performance in low light conditions.
Hybrid panels of crystalline and thin-layer silicon have been produced to combine higher efficiency with low light efficiency, offering the best of both worlds.
Efficiency of solar panels
The amount of electricity a panel generates against the amount of sun energy required to generate it, gives the efficiency. If 500W of the sun’s energy is required to generate 50w of electricity, the panel would be 10% efficient
Crystalline efficiencies range from about 11% to 14%, with mono-crystalline being the most efficient. In some hybrid panels of mono crystalline silicon combined with thin-layer, efficiencies as high as 24% have been achieved.
The efficiency of thin layered panels range from 6% to 11% but, in terms of cost, they are still good value and their low light performance can make them better suited to shady climates.
Solar power is a clean efficient means for houses to generate up to a third of the home’s electricity using renewable energy, whilst also benefiting from a generous annual Government incentive, interest linked and paid to you for 20 yrs.
Photovoltaic (PV) cells are not a new invention. These ‘microgenerators’ are currently the world’s most expanding form of renewable energy and the most popular clean alternative to fossil fuel power.
Because it is relatively cheap and clean to install, can apply to most domestic and commercial properties and, with incentives, can earn back considerably more than the cost of installation
Semi-conductor plates in solar panels generate direct Current (DC) electricity in the presence of sun light. When converted to the more familiar alternating current (AC) through an inverter, this can power electrical appliances in domestic and business environments in exactly the same way as electricity bought from conventional suppliers.