ABOUT SOLAR

Solar Cell Technology

A solar cell is a device that converts sunlight into electricity and typically about the size of a greeting card, but less than half a millimetre thick. At the heart of a solar cell is a tiny electric field that splits negative charges from positive charges using the energy of sunlight. It is an incredible invention and the only way we make electricity on Earth at scale, without any moving parts. When sunlight shines on a solar panel, the DC electricity that it produces is transported by conducting wires into an inverter, which transforms the electricity into the 240V AC supply that we use to power our fridge, TV, lights and hot water system.

Solar Cell Efficiency

The efficiency records for solar cells are continually increasing with improvements of new material combinations and smart engineering ideas. It takes about two to five years for a solar panel to "pay back" the energy that went into making them (depending on how sunny it is where you live). Queensland is leading the way in solar power and battery storage as the number of Australian homes adopting the technology has seen a dramatic increase in recent times. There is more than one and a half million solar-powered homes in Australia generating around half of their own electricity needs with more than 32% of homes in Queensland with solar panels on their rooftops making it the biggest power plant in Queensland.

How Solar Cells work

At the heart of a solar cell is a tiny electric field that splits negative charges from positive charges using the energy of sunlight. In a silicon wafer solar cell, the electric field is set up with the help of small amounts of other atoms. On one side of the wafer are some boron atoms (with one less electron than silicon) and on the other side are phosphorus atoms (with one more electron). Together they create what is called a positive-negative (p-n) junction. Opposites usually attract, but the p-n junction forms the electric field that is able to drive positive and negative charges apart. When sunlight is absorbed by the solar cell an electron is knocked free inside the silicon and pushed across the wafer due to the electric field. It can then be collected by metal contacts to become usable electricity.

Solar Panels efficiency

The efficiency records for solar cells are continually increasing. The improvements are thanks to the use of new material combinations, advanced anti-reflection coatings, clever semiconductor processing that avoid electrical losses, and other smart engineering ideas. The world's mass-producers of solar cells are continually incorporating these advances into their own solar cells, meaning that the panels on rooftops are steadily getting more efficient too.

How 'green' are solar cells?

It takes about two to five years for a solar panel to "pay back" the energy that went into making them (depending on how sunny it is where you live). This includes the energy needed to mine the silicon and process it into a solar cell, and also make the aluminium frame and glass in the panel module housing. Solar panels usually come with a guarantee of 80 per cent output for 25 years and there is no reason why they should not last longer, which means energy-wise solar panels are a good thing. Silicon is the second most abundant element in the Earth's crust, so there will not be any material shortages in the foreseeable future. And, sunshine itself is the most sustainable resource we have.