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In Australia's climate, the sun is often hot enough to fry eggs. But why stop at breakfast? Capturing the rays with solar panels can provide enough electricity to take care of lunch and dinner, and all the activities in between.
Sunlight is entirely free and, most importantly, extracting it for your daily use has a low impact on the planet - a lot lower than many other methods. But there is a cost in purchasing and maintaining equipment to capture the sun's energy.
Solar panels (or photovoltaic cells) are mostly made of individual silicon crystal cells wired together to generate DC electricity when they are struck by light energy. The more sunlight that hits them, the more electricity they produce.
Typically, panels are between 12 and 17 per cent efficient - which doesn't sound like much, but is a great improvement on the 3 to 3 per cent efficiency of the 1970s.
Solar panels are the much talked about 'clean energy' technology … but what do you need to know before installing them?
The basic system
A solar cell can only generate electricity; it cannot store it for later use (such as when the sun is not shining).
With a simple system, you can use the electricity to run a DC electric appliance, like a fan to ventilate a car or hot shed, while the sunlight hits the cell.
Your roof is a good location for solar panels, but it can be installed anywhere that receives sunlight.
If you have basic DC electricity knowledge, and can use a soldering iron or crimping tool - and don't mind hanging out on the roof - you can install a system like this in a few hours.
There are no rebates for this type of system, but set-up and maintenance costs are generally low, and the cells are very robust, boasting a life of about 40 years.
Storage
It's more likely that you'll need the electricity to be available when the sun isn't there - to power lights, for example.
Because basic systems are typically small - enough to power a single light or a few efficient appliances - storing electricity might be a good way to make the most of the cells.
Storage batteries range in price from under $100 to around $1,000. Investing in one gives you the flexibility to use the electricity any time you like. In this way you can run lights, radios and even televisions using 12- or 24-volt DC straight from the battery.
To run your typical 240-volt AC appliances you'll need to add an inverter to your system. This device converts the DC electricity from the battery to mains power and can be used in homes or vehicles.
You can simply plug in your household equipment and it works! Well, within limits.
Your solar electricity system isn't infinite: the batteries can only store a limited amount of electricity and will run flat if more energy is taken out than put in. Fortunately, the maths is simple, and there are some monitoring devices can help you manage your electricity usage.
There are many types of storage batteries for solar electricity systems, including lead-acid (car batteries are one example), and gel batteries.
If you have a system that cannot be connected to the power grid - known as 'remote' - you may also need a back-up generator so that your home can continue to function through peak loads (such as using power tools, parties, or emergencies) or long periods with little sunlight. Many types are available; most are powered by petrol or diesel engines.
The cost of running and maintaining these adds to the economic and environmental cost of remote systems - but it's a necessary evil if you cannot connect to the grid.
The 'business as usual' system
A straightforward way to manage all this is a system that connects to the mains electricity grid. It works when your solar system generates electricity through the sunlight hours and then supplies the surplus energy to the grid - putting power back into the grid and running your meter backwards! Your home essentially becomes a mini-power station and the electricity supplier buys the surplus energy from you.
This system allows your home to run as normal, requiring no additional work or thought from you - except to check your bills to see how much money you're saving and how many tonnes of carbon dioxide you're keeping out of the atmosphere.
On average a standard 1,000-Watt system saves around 1,500 tonnes of carbon dioxide emissions each year.
Suppliers often make it easier to set up by selling packages for remote sites, grid connection, and mobile systems for boats and recreational vehicles.
Maintenance costs are virtually nil. There are no batteries and the panels are long-lived. Cleaning from time to time will keep them at peak performance.
Where to install your panels
To get the most out of solar panels, ideally, you would place them on a north-facing roof at an incline of around 30 degrees to catch the most sun.
But if your roof doesn't receive much sun through the day - maybe you live on the south side of a hill, or you're shadowed by tall buildings - you may need to go to extra lengths to generate reasonable amounts of electricity. Panels can also be mounted on poles or other structures to reach for more sun.
A new kid on the block is the amorphous cell, which is better at producing electricity in shade than other types. These cells are so-called because their silicon crystals are not regular in shape.
The individual cells are typically long and narrow, making them less likely to be substantially shaded than other 'squarer' cells. This is important, because the cells in most solar panels are connected in series, so if one's out (due to shade) they're all out!
Amorphous silicon has an efficiency of 5 to 9 per cent and can be used in rigid thin-film modules (sandwiched in glass) or flexible thin-film modules (sandwiched in plastic).
How big?
To get a quick idea of the size of solar electricity system you will need, go to Origin Energy's useful solar calculator and enter the amounts from your last four electricity bills.
Domestic systems range from around 600 Watts for around $4,000 (after the government rebate) to about 3,500 Watts for around $32,000 (after the rebate).
As a guide, a mid-order 1,000-Watt system with about six large panels (which can supply a large proportion of electricity for a typical energy-efficient household) will cost upwards of $14,000.
On the face of it, it looks like a lot of money. The good news is that federal government incentives of $8 per watt (capped at $8,000) are available to encourage installation of solar electricity systems.
This brings the cost down to a much more reasonable $6,000.
To receive your rebate, the person who carries out the installation must be accredited for design and installation of photovoltaic systems by the Clean Energy Council.
For a monthly bill of about $100 you can save a much larger four per cent of your annual bill. You can shorten the time further if you can reduce your energy consumption.
It's possible to even make money from your system if, for example, your home was unoccupied for a few months while you are away on holidays. During this time the home uses virtually no electricity, so any electricity generated actually runs your meter backwards - crediting real dollars to your account!
As the solar industry grows and garners more support, competition will continue to bring prices down, making the switch to solar even more affordable. In the meantime, whether you invest in one solar panel or a roof full of them, there's plenty of sun to go around.
