Solar power harnesses energy from the sun.
It is generated in two ways. The first is directly with photovoltaics - that is, solar panels. The second is indirectly, by concentrating sunlight via lenses or mirrors, and using it to boil water, or a more volatile liquid, which is then used to provide power.
Concentrated photovoltaics uses the same principal of concentrating sunlight to shine it on solar panels to increase efficiencies. Solar photovoltaics are the fastest growing energy technology in the world. Over 1.5 million homes worldwide have rooftop solar PV feeding into a grid. [PDF]
Global uptake of solar energy is increasing dramatically. [visualise] The country with the greatest total PV capacity is Germany. The highest installed capacity per capita is Spain. [PDF]
Despite having the highest average solar radiation of any continent in the world, Australia has only a very small number of working solar thermal power systems. The largest is at the Liddell Power station in the New South Wales Hunter Valley, which is a demonstration plant of around 1.5 MW. However, a larger system is being planned for the site. The CSIRO is also constructing a 0.5 MW solar thermal power station in Mayfield, New South Wales.
In 2009 the Federal Government announced the $1.5 billion Solar Flagships Program to help fund the construction and deployment of up to four large-scale solar power stations of around 250 megawatts, of which two can be solar thermal.
Around 7% of Australian households use solar energy for heating water. Government incentives have also encouraged PV installations to rise dramatically in recent years: between 2007 and 2008 there was an increase of 80%. Of this, nearly 69% were grid-connected. [PDF]
Solar Credits are a Federal Government incentive that offers tradeable Renewable Energy Certificates (RECs) for the installation of eligible small-scale solar PV, wind and hydro electricity systems. Generally owners transfer the right to create RECs to their installer in return for a discount on the price of the system being installed.
Further support for the installation of PVs is provided under the Australian Government’s Solar Cities Program. The cities in the program are Adelaide, Alice Springs, Blacktown, Central Victoria, Moreland, Perth and Townsville.
The current cost of solar energy remains one the largest impediments to its growth: compared to hydrocarbon fuels it is significantly higher.
Whereas coal-derived electricity averages about 5 cents per kilowatt hour, photovoltaic generated solar power averages about 20 cents per kilowatt hour, depending on whether it is generated at a solar power plant or on a house or small building.
However, recent improvements in photovoltaic systems and solar reflectors have the promise to improve operating efficiencies and decrease costs substantially in the next decade.