CPV in Australia's Red Centre

Indeed, the central Australian region receives more sunlight than any other region in Australia, with over 7 kWh/m²/day of incident radiation, according to the Australian Solar Radiation Handbook 1994. Furthermore, whilst the local solar resource is high, the arid climate – which varies from blisteringly hot summers and sub-zero evening temperatures in winter – results in electricity consumption which is above the Australian average in homes and businesses.

These are just some of the reasons that Alice Springs was chosen to participate in the Australian government-funded energy efficiency pilot programme, known as Solar Cities. Under the Solar Cities programme, which was launched in 2004, seven cities throughout Australia were chosen to participate, with each Solar City delivering a unique trial covering a combination of energy efficiency measures; solar energy technologies; energy pricing trials; and, smart metering technologies.

The other Australian Solar Cities are Townsville (North Queensland); Blacktown (West Sydney); Coburg and Bendigo (Victoria); Adelaide (South Australia) and Perth (West Australia).

The Alice Solar City project (www.alicesolarcity.com.au) utilises a combination of innovative community engagement programmes, alongside high and low technology interventions and measures to empower the community to make informed and intelligent use of energy. Launched in 2008, Alice Solar City is led by the Alice Springs Town Council and is supported by a Consortium of local organizations. In just two years, the project has already attracted more than 20% of the town households to participate in the voluntary residential programme, as well as more than 100 local businesses. Each participant receives a free, comprehensive, energy audit and a tailored energy saving report. The project also offers residents and businesses funding to implement measures identified in their audit. These range from low tech measures like painting roofs white, through insulation, energy efficient lighting, window tinting and, of course, solar water heating and photovoltaic solar systems.

A range of other interventions and measures are being tested to ascertain their ability to influence energy use behaviour, including smart metering, peak and off-peak tariffs and interactive in-house displays of electricity use. The in-house displays communicate wirelessly with the smart meters, showing a range of information on occupant electricity consumption patterns, and where solar PV systems are installed, this is overlaid with solar generation data. This important element of the project aims to test whether having detailed live and historical information on electricity consumption available to consumers will lead to longer-term changes in their behaviour, load shifting and overall reductions in energy use. Alice Springs is serviced by its own grid, with gas and diesel being the fuel sources of a total local generation capacity of around 65 MW. Local electricity retailer, Power and Water Corporation are key partners on the project, keen to assess the impact of these technological and consumer engagement interventions, as well as a range of cost reflective electricity tariffs designed to encourage consumers to shift load to off-peak times.

Iconic Solar Energy Installations

In addition to the residential and commercial streams, Alice Solar City has supported and encouraged the development of five major ‘iconic’ projects in and around Alice Springs that will play a critical part in the strategy of making Alice Springs a national and international showcase for sustainable living and the use of renewable energy.

These projects will demonstrate large-scale renewable energy technologies, including a variety of cutting edge solar photovoltaic concentrator and solar thermal technologies.

In April 2010, work commenced on the second of the five ‘iconic’ solar energy projects being developed as part of Alice Solar City, a 235 kW concentrating solar photovoltaic installation at the Alice Springs Airport. The project came about after Alice Springs Airport undertook a formal Request for Proposals (RFP) to the national solar energy industry in mid-2009 to identify suitable solar technology options. Whilst cost (value for money) as measured by cost per kWp installed and cost per MWh delivered, were key factors, similar weighting in the assessment of responses was given to technology type and status, that is the ‘iconic’ nature of the technology, environmental suitability, reliability and maintainability.

After assessing 21 responses to the RFP, Queensland-based Ingenero Pty Ltd was selected to install the 235 kW solar power station, comprising 28 SolFocus SF-1100 concentrating photovoltaic (CPV) dual axis tracking arrays. Each array is rated at 8.4 kW peak and measures eight metres wide by seven metres high.

According to Ian Kew, chief executive officer of Northern Territory Airports, ‘Alice Springs will be the first Australian airport to have a large-scale (over 100 kW) photovoltaic system providing a direct source of renewable energy to its internal grid. It will be on display to travellers, visible from both the ground and the air.’

CPV technology is particularly effective in areas of high Direct Normal Incident radiation (sunny locations) like Alice Springs. The system is expected to produce around 600 MWh annually, equivalent to around 28% of the airport’s annual electricity demand. Total value of the project, which is expected to be completed by August 2010, is A$2.26 million (US$1.97 million), with 50% of the funding being provided from the Australian government as part of Alice Solar City project and the balance coming directly from Alice Springs Airport. SolFocus intends to use one of the 28 airport arrays as a research and development tool to help gather data and test new products in Alice Springs’ arid climate.

An emerging solar technology, CPV systems are offering significant potential for cost reductions in photovoltaic installations. As opposed to traditional PV systems, which use a large amount of costly photovoltaic material, CPV technology uses smaller amounts of semiconductor in conjunction with less expensive materials such as glass, plastic and steel, to concentrate sunlight and direct it onto a much smaller PV cell.

Whilst this will be the first deployment of the Solfocus technology in Australia, it is not the first CPV system to be installed in the Northern Territory. There are existing CPV systems installed in several remote Aboriginal communities whose power was exclusively supplied by Power and Water Corporation diesel mini-grids. These use technology developed by Australian pioneers, Solar Systems Pty Ltd. A total of 30 Solar Systems CPV dishes are installed across three sites across the Northern Territory, collectively reducing diesel consumption by about 500,000 litres a year.

Other Iconic Projects

The Alice Springs Airport project will be the second iconic project to be completed in Alice Springs, following the 304 kW solar PV system installed on the roof of the Crowne Plaza Hotel in 2009. Using SunPower flat plate technology, the Crowne Plaza installation was at the time of completion the largest roof-mounted grid-connected PV installation in Australia.

Above: The 304 kW system at the Crowne Plaza hotel, the city's
first 'iconic' installation

The three other iconic projects being developed under the auspices of the Alice Solar City programme showcase a variety of other solar technologies and applications. For example, the new Aquatic Centre currently under construction will be one of the largest solar pool heating systems in Australia. A total of 275 collectors will provide heating for the new swimming pool, cutting gas consumption by at least 30%, or the equivalent of 3454 GJ per annum.

A solar farm just shy of 1 MW in size is also under development, with construction expected to commence in the second half of 2010. Utilising a single axis flat plate tracking array, the output of the 963 kW solar farm will be sold to local electricity retailer, Power and Water Corporation, which will in turn sell on this energy as part of a ‘green’ tariff to residential and commercial customers. Once completed the solar farm project will be the largest tracking photovoltaic system installed in the Southern Hemisphere.

The final iconic project being developed under the programme is a solar air-conditioning system at the town’s main cultural centre, the Araluen Cultural Precinct, for the Araluen Arts Centre. This proposed system will replace existing, ageing equipment and will largely consist of two major structures – a field of solar array collectors and a thermal plant room. The system will use single axis parabolic troughs to deliver heat transfer fluid (HTF) at 180°C, which in turn will operate a double effect absorption chiller. The solar array field will be made up of 46 collectors comprising of 630 m², with the collectors using oil as the HTF. As there have been few examples of solar air-conditioning systems installed in Australia to date, this installation is seen as an important step to assist in increasing awareness of solar energy for both heating and cooling applications.

The overall amount of activity in this small town over the last few years is impressive, with residential and commercial sectors seeing around 290 individual solar systems installed with a total installed capacity of approximately 720 kW. When the total capacity of existing and planned iconic systems is completed, around 2.2 MW of distributed solar generation will be in embedded in the town’s local electricity grid. With a total capacity of around 65 MW, and winter/summer daytime loads ranging from 25–55 MW, this represents one of the highest penetrations of solar energy generation on a network of this size in Australia, if not the world. It is further anticipated that a local campaign to encourage further uptake of rooftop solar, entitled ‘1000 roofs in 1000 days’ (which is aiming to achieve 1000 solar installations by the 1000th day since the Alice Solar City project launched) will add further solar generation to the local network.

Solar Demonstration Centre

Alongside the Solar City initiative, Alice Springs is also home to the world class Desert Knowledge Australia Solar Centre. The aim of the Solar Centre is to demonstrate a wide range of solar energy technologies and applications and compare their performance in the desert environment. Photovoltaic technologies installed at the Solar Centre include traditional mono crystalline, polycrystalline and amorphous modules in a range of configurations: cadmium telluride thin-film; copper indium gallium selenide; and HIT (Heterojunction with Intrinsic Thin Layer) panels. In addition to these technologies, a number of the arrays on display are mounted on single and dual axis tracking units as well as tracking concentrating PV systems with gallium arsenide (GaAs) V-III cells. Given the extremes of climate (very hot, dry dusty summers and sub-zero temperatures in winter) the Solar Centre is seen as the ideal location to demonstrate these latest generation tracking technologies and evaluate the cost benefit of tracking systems when compared with fixed mounting systems.

The facility managers and engineers, CAT Projects, have received consistently positive feedback about the facility and are in negotiations with a number of companies to establish further commercial test installations. Lyndon Frearson, general manager of CAT Projects explains: ‘We have over two thousand people regularly accessing the raw data, as well as over 200 people a day accessing the graphical part of the website – users include venture capitalists, investment banks, utilities, engineering consultancies, universities and government agencies. This clearly reflects the significant interest in the Solar Centre and the value of the data that is being produced. It is a truly unique installation for both Australia and indeed the world.’

The performance of all the installed technologies at the Solar Centre is being independently captured, with both live and historical output data, and is freely available on display at the website: www.dkasolarcentre.com.au.

In addition to the Alice Solar City initiative, Alice Springs is the home of the award-winning Bushlight programme, developed by the Centre for Appropriate Technology, a local NGO working to improve the livelihoods of indigenous communities by increasing access to sustainable energy supplies.

Bushlight (www.bushlight.org.au) works in the most remote regions of Central and Top End Australia, where communities are isolated by hundreds of kilometres of dirt roads, can be cut off by floods, and have no access to town water, power and other services that larger towns take for granted. Without reliable access to fresh food and refrigeration, fuel and qualified technicians, Australia’s remote communities need sturdy, innovative and interactive energy services. Prior to Bushlight, power supply in remote indigenous communities was typically unreliable, often not 24 hours a day and expensive. This had a range of negative social, environmental and health impacts on the communities.

The programme addresses power supply in these remote communities by having a strong focus on community engagement in the energy planning process, and by designing robust, technically advanced stand-alone renewable energy systems. This approach operates through a dynamic partnership with local councils, resource agencies, community members and technical contractors. The process is supported by a range of culturally appropriate resources designed specifically for local conditions. By involving the local community in the design and various aspects of the on-going maintenance of the power system, Bushlight has had significant success in improving this critical element of remote community life. Based on the success of the programme locally, Bushlight systems are now being exported to India.

With operations commencing in July 2002, by 2010 Bushlight had installed 115 renewable energy systems, providing reliable 24-hour power to over 3000 people living in remote communities in Australia. Bushlight also provides a maintenance service to almost 250 renewable energy systems installed in indigenous communities.

Policy and Legislative Background

Alice Springs is situated in the Northern Territory, a vast region covering central and northern Australia with a land area of some 1420 million km² (almost six times the area of UK) but which has a population of just 224,000. The Northern Territory has a small but rapidly growing economy, with minerals and energy, alongside tourism and agriculture as its main industries. Like many regions in Australia, the Northern Territory government recently released its own Climate Change Policy, which includes a headline aspirational goal of a 60% reduction in carbon emissions by 2050, compared with a 2007 baseline. Of note, the policy calls for the Territory to become a world leading generator of renewable and low emissions power in remote communities – there are currently 55 remote communities that are currently serviced by diesel powered mini-grids.

At the national level, the main instrument to encourage the development and deployment of renewable energy technology in Australia is the Mandatory Renewable Energy Target (MRET). Commencing in 2001, the MRET placed a legal liability on wholesale purchasers of electricity to proportionally contribute to an additional renewable energy generation of up to 9500 GWh or around 2% of Australia’s electricity demand. In August 2009, the government passed legislation to expand the MRET to ensure that renewable energy obtains a 20% share of electricity supply in Australia by 2020. To ensure that target is reached, the government has committed to expand on the progamme and the MRET is now set to increase from the original requirement of 9500 GWh to 45,000 GWh by 2020. The scheme lasts until 2030.

The MRET provides renewable energy power stations and owners of solar water heaters and small generation unit installations (small-scale solar PV panels, wind and hydro electricity systems), with a financial incentive through the creation and trade of renewable energy certificates (RECs) via the REC Registry. Each REC – which represents 1 MWh of renewable energy generated from an eligible energy source – can be sold for a negotiated price and transferred to liable parties, usually wholesale purchasers of electricity.

An issue that has been hotly debated over the last year in Australia has been over the development and implementation of a national emissions trading scheme, referred to in Australia as the Carbon Pollution Reduction Scheme (CPRS). After legislation to introduce the CPRS was twice defeated in the Parliament, in April 2010, the Prime Minister announced that the government has decided to delay the implementation of the CPRS until after the end of the current commitment period of the Kyoto Protocol in 2012, and only when there is greater clarity on the actions of other major economies, including the US, China and India.

Nonetheless, whilst the national and international debates continue over issues like emissions trading, the small town of Alice Springs in central Australia is winning ground in the batle to deploy solar energy technology and improve energy efficiency in homes and businesses. CPV is on the front line.

Enjoyed this? Get more coverage with a free subscription to Renewable Energy World magazine