CONCENTRATED SOLAR THERMAL ENERGY FACT SHEET
As the sunniest continent on Earth, Australia has a unique opportunity to embrace
solar energy as a mainstream option for our future energy mix.
About Concentrated Solar Thermal in Australia
•
Concentrated Solar Thermal (CST), also known as Concentrated Solar Power (CSP), is one of Australia’s
most viable options for large-scale solar power generation and other forms of solar energy.
•
Australia is currently facing a unique opportunity to take the lead in a rapidly growing international
industry, with CST energy predicted to make up 30 to 50 per cent of Australia’s power consumption
by 20501.
•
In 2012, there were five demonstration and experimental CST power plants in Australia.
What is Concentrated Solar Thermal energy?
CST energy uses reflectors (like mirrors)
to focus and harness sunlight into
concentrated heat energy.
Heat
Steam
Power
This energy is then generally used to
heat a fluid, like water or oil, which in
turn produces steam or hot air2. The
steam is then used to drive a turbine
connected to a generator to produce
electricity.
The diagram to the right depicts a
typical solar array, a two-tank thermal
storage system, a steam generator and a
conventional power block.
Solar array
Heat storage
Steam
Power block
What is the difference between solar thermal and solar PV?
Photovoltaic solar, or solar PV, takes the energy collected from the sun by solar panels and converts it
directly to electricity. Solar thermal, on the other hand, takes the energy from the sun and converts it first
to heat, and then to electricity.
One of the main benefits of solar thermal over solar PV is that the energy can be stored at the heat stage,
meaning it can be a more reliable source of electricity. Energy can be stored during times of high output
or low demand, and then converted to electricity later to provide a steady source of both peak and
base-load electricity.
denergy
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hydroelectricity
The Cleanhydroelectricity
Energy Council (CEC) is the peak body representing
Australia’s clean energy sector. It is an industry association made
up of more than 550 member companies operating in the fields
of renewable energy and energy efficiency.
energyefficiency
stand-alone
largescale solarhotwater
solarthermal
solarhotwater
solarthermal
bioenergy
visit cleanenergycouncil.org.au
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CONCENTRATED SOLAR THERMAL ENERGY FACT SHEET
Types of concentrated solar thermal energy
Concentrated solar thermal energy is being deployed at large scale to provide electricity
around the world. Types of CST technology include3:
Linear Fresnel
Tower
• Long rows of flat or slightly curved mirrors,
moving independently on one axis.
• Energy from the sun is reflected up to fixed linear
receivers mounted on towers above the mirrors.
• This type of technology is moving to the
commercial stage around the world, with 38
megawatts (thermal) capacity as at 2011.
• An array of heliostats (large mirrors with two-axis
tracking) concentrates sunlight onto a fixed
receiver at the top of a tower.
• A large single receiver converts the energy to
heat through complex processes like the direct
heating of molten salt. This allows large amounts
of energy to be stored.
• This type of technology is slowly moving to the
commercial stage with 60 megawatts (thermal)
installed capacity globally as at 2011.
Dish
Trough
• Paraboloidal or dish shape with two-axis tracking
that focuses sunlight to a point receiver.
• The most optically efficient of all CST types as
the shape results in the least loss of sunlight.
• The technology is still emerging, with 6
megawatts (thermal) of installed capacity
globally as at 2011.
• The most widely deployed CST technology,
with 1,400 megawatts (thermal) installed
capacity as 2011.
• A parabolic mirror tracks the sun from east to
west, focusing energy onto a linear ‘evacuated
tube’ receiver. The tracking system means
the solar panels are always getting maximum
sunlight.
• Trough is a mature technology with systems
operating around the world for over 25 years.
denergy
smallwind
energyefficiency
windenergy
stand-alone
solarpv
largescale
solarpv
solarpv
smallwind
hydroelectricity
The Cleanhydroelectricity
Energy Council (CEC) is the peak body representing
Australia’s clean energy sector. It is an industry association made
up of more than 550 member companies operating in the fields
of renewable energy and energy efficiency.
energyefficiency
stand-alone
largescale solarhotwater
solarthermal
solarhotwater
solarthermal
bioenergy
visit cleanenergycouncil.org.au
solarpv
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CONCENTRATED SOLAR THERMAL ENERGY FACT SHEET
Why concentrated solar thermal energy?
Flexibility
Proven technology
Most solar thermal plants also have a fuel-power
backup, meaning CST can provide a firm and flexible
source of renewable energy that can be dispatched
when required. CST energy provides utilities
and network planners with flexible electricity
production capacity while also allowing for effective
management of a greater share of variable energy
from other renewable energy sources, such as solar
PV and wind energy.
CST energy is a proven technology that was first
commercialised at large-scale in the Californian
desert in 1984. CST power plants have delivered
reliable renewable energy to communities in the
United States, Spain and more recently, India,
Northern Africa and the Middle East. The industry
continues to develop rapidly with an estimated
1.76 gigawatts of installed solar thermal energy
around the world and up to an additional 2
gigawatts currently in construction4. There is no
doubt that CST power has the potential to play a
substantial part in Australia’s future energy mix.
Competitive power price
Although CST is considered a proven technology,
it is still in the early stages of development, making
it more expensive when compared with wind and,
more recently, solar PV. As the technology develops
and improves over the next few years, costs will
come down substantially, making CST a viable
long-term option for Australia’s future energy mix.
The ability of CST power plants to supply electricity
in peak times also means it can offset other, more
expensive types of peak electricity generation. In
the long run this could help reduce the wholesale
price of electricity, while also removing the need for
costly network upgrades to deal with peak demand.
denergy
1
ASI, Realising the Potential of Concentrated Solar Power in Australia,
May 2012 Pg. 34 http://www.australiansolarinstitute.com.au/SiteFiles/australiansolarinstitutecomau/CSP_AUST_Final_May2012.pdf
2
Heating fluids are the generally used however there are some thermochemical CST systems
3
ASI, op cit, Pg. 12
4
REN21, Renewables 2012 Global Status Report, Pg. 51
5
IEA Solar Energy Perspectives 2011
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The way CST power plants work, by first converting
solar energy to heat, means that they are able to
store large amounts of energy. This makes CST
plants effective at providing reactive power, or both
peak and base-load electricity.
Development benefits
The global CST industry is quickly expanding, and is
estimated to account for 28 per cent of total global
electricity generation or 6000 gigawatts of capacity
(with storage) by 20605. With a great solar resource
and a long history in innovation, Australia has the
potential take the lead in this growing market in
the long-term. Building CST plants will provide
an opportunity for applied research into new CST
technologies right here in Australia. Whether through
projects or exporting our expertise, developing the
CST industry will lead to increased employment and
investment opportunities locally.
Reducing the diesel consumption of mining operations
As some of Australia’s best solar resources are
located in the key mining states of Western Australia
and Queensland, CST has the potential to play an
important role in reducing the diesel fuel consumption
of mining operations. The opportunities for off-grid
and end-of-grid renewables in mining operations are
only just beginning to be explored, and CST is one of
the leading technologies for consideration by mining
companies looking to power their operations at
lower cost using clean energy.
hydroelectricity
The Cleanhydroelectricity
Energy Council (CEC) is the peak body representing
Australia’s clean energy sector. It is an industry association made
up of more than 550 member companies operating in the fields
of renewable energy and energy efficiency.
energyefficiency
stand-alone
largescale solarhotwater
solarthermal
solarhotwater
solarthermal
bioenergy
visit cleanenergycouncil.org.au
solarpv
solarpv
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