In 2019, a venture called “Sun Cable” was announced. The idea behind it is to generate electricity from a solar PV installation in northwestern Australia and transmit power to Singapore via the world’s longest high-voltage direct current cable.
Background
Project Overview
Sun Cable is building the world’s largest solar energy network, which will allow clean energy to power Australia, Singapore and other ASEAN markets. The project also aims to provide interconnection transmission of solar energy across the participant countries. This initiative would make it easier to electrify existing and growing sectors, thus promoting large-scale industrial growth and lowering carbon footprint [1]. The primary purpose of Sun Cable is to construct the world’s largest intercontinental electricity network, linking Australia to Singapore and supplying clean energy 24 hours a day and seven days a week.
The Sun Cable project intends to create a massive solar power plant throughout central Australia, coupled with energy processing and then link everything to Singapore through an undersea cable, mostly on an unparalleled scale.
The mega solar power project that Sun Cable is constructing is estimated to be completed with an overall budget of AUD 30 billion.
Figure 1. Rendered aspect of the 20 GW solar PV power plant within the AAPowerLink project. Source: https://helioscsp.com/masdars-shams-1-concentrated-solar-power-plant-now-powers-20000-homes/
Singapore-based Sun Cable, the company planning to build the world’s largest solar and battery energy storage project in the Northern Territory (NT) in Australia and export it to Singapore, has submitted a summary of the Environmental Impact Statement (EIS) that reveals its full magnitude. According to the EIS, the Australia-Asia PowerLink (AAPL) project will generate its renewable energy through a 17-20 GW solar park with 36-42 GWh of battery energy storage called Powell Creek Solar Precinct, which will occupy 12,000 hectares in the Barkly region, in the NT.
The document presents as the main benefits of the project the reduction of greenhouse gas emissions by 480 million tons over the 70-year life of the project (equivalent to the average electricity used by more than 2.5 million Australian households per year and saving 10% of NT GHG emissions).
Sun Cable presumes the project will have the capacity to supply 15% of Singapore’s energy needs. The financial closure of the project is planned for the end of 2023, and construction will begin as early as 2024. An indigenous land use agreement with native title holders is being negotiated through the Northern Land Council.
Project Partners
US engineering, procurement and construction giant Bechtel, professional services firms Marsh and PwC Australia, North American transmission specialist Hatch, and Australia-based engineering firm SMEC, a member of the Singapore-based Surbana Jurong holding group, are listed as members of the project’s execution team.
AAPowerLink is the latest in Australia’s list of renewable energy projects SMEC has worked on. The company said it had been directly linked to the development of more than 6.4 GW of commercial-scale solar parks in Australia, including Risen Energy’s 100 MW Yarranlea solar park in Queensland and the massive 720 MW New England solar park being developed by UPC/AC Renewables Australia in New South Wales [2].
SMEC is also involved in the EnergyConnect project, a 900 km electrical interconnector proposed by the grid operators TransGrid and ElectraNet, and the $4.6 billion Snowy 2.0 pumped-storage hydroelectric project, which, when completed, will provide 2 GW of on-demand renewable energy and approximately 350 GWh of large-scale energy storage to the National Electricity Market (NEM).
In November 2019 and December 2021, Sun Cable successfully raised significant amounts of money with cornerstone investments from Mike Cannon-Brookes’ Grok Ventures and Andrew Forrest’s Squadron Energy, as well as a variety of private investors. Sun Cable appointed PWC as AAPowerLink’s Project Advisory Partner, providing financial, tax, and legal advisory services.
Sun Cable is a proud member of the Clean Energy Council, the International Cable Protection Committee, the Sustainable Energy Association of Singapore, and Cigre (for power system expertise). In June 2022, The Australian Government’s Infrastructure Australia awarded the AAPowerLink Stage 3 Investment Ready status on the 2022 Infrastructure Priority List [3].
Technical Features
The Power Plant
The northern part of Australia is known for its high insolation levels, favourable conditions for wind farms and immense availability of land, offering an attractive environment for significant utility-scale renewable developments. Dominant regions with high incident solar radiation (ISR) include the northwest deserts and the centre of the continent. These correspond to areas without a well-established National Electricity Grid. Solar PV developers have identified several regional locations suitable for solar power plants based on high solar radiation fluxes and proximity to transmission infrastructure. Within the National Electricity Market grid area, Port Augusta (South Australia), northwest Victoria, and central and northwest New South Wales (including Mount Isa, Alice Springs and Tennant Creek), have been identified as having high potential for solar thermal powered investments, which also corresponded to their high levels of ISR. Kalbarri in the vicinity of Geraldton (Western Australia), the South-West Interconnected System, the Darwin-Katherine Interconnected System, and Alice Springs–Tennant Creek can also be considered potential solar-powered sites for evaluating solar energy assessment models and assessing the long term feasibility of developing massive solar power projects in these areas.
Recently, a few ambitious projects were proposed by developers to leverage this Australian renewable energy potential to generate and export clean electricity to Southeast Asia.
The goal of Sun Cable is to deliver renewable electricity at scale from resource-rich regions to expanding load centres. The first step in this process is the Australia-Asia PowerLink (AAPowerLink), which will exploit Australia’s vast solar resource to supply substantial amounts of dispatchable, competitively priced, and renewable electricity to Darwin and Singapore.
The AAPowerLink will have the most extensive battery energy storage system, the largest solar generation site, and the most extended subsea cable transmission system in the world, with a combined capacity of between 17 and 20 gigawatts, 36 to 42 gigawatt hours, and 4,200 kilometres, respectively.
Figure 2. Indicative map route for the Australia-Asia PowerLink. Source: https://suncable.energy/
The Maverick prefabricated and pre-wired system, designed by manufacturer 5B of Sydney, has been chosen as a module for the AAPL project. These arrays will be arranged in blocks of approximately 23-28 MW of maximum DC capacity and linked to about 60 MWh of storage.
The storage system comprises lithium-ion batteries with an estimated lifetime of ten years. The battery has three main components: the cells, the module, and the pack. The production of the pack and modules is quite standardised, mainly involving aluminium, copper, and steel as raw materials. On the contrary, the cells are very specific in each battery [4].
The Transmission Line
From the Powell Creek site, an 800 km, 6.4 GW overhead transmission line will carry solar power to the Darwin conversion centre in Murrumujuk, where some 800 MW will be supplied to Darwin and private industry. The rest will reach the Gunn Point Beach cable transition facility, where up to six 4,200km parallel submarine cable systems will transmit power to Singapore.
The cable is one of the main components of this project because of its dimension and capacity. The life span is expected to be 40 years [5]. The copper cable conductor material is covered by an insulation layer comprising impregnated paper (IP) with high-voltage grade impregnation and cross-linked polyethylene.
The water-blocking sheath consists mainly of a lead layer. To ensure tension stability and mechanical protection, the cable is covered with galvanised steel armour and finally protected with a polypropylene sheath.
In the absence of an exact route, we can consider obstacles, such as deep-sea trenches, which would lead to higher costs and material demand for small cable sections.
Figure 3. HVDC submarine cable cross‑section design. Source: https://doi.org/10.1007/s41825-020-00032-z
The integration of remote renewables into established electrical systems to displace non-renewable generation is now possible because of advancements in HVDC and cable technologies. HVDC projects with cable connection lengths larger than 3000 km are currently being developed. A significant percentage of the solar energy resource is centred on the Australian and African continents and load centres in Europe and the ASEAN areas.
Researchers developed a frequency-dependent (FDM) DC cable model for the AAPowerLink [6]. The effect of field joints and the associated earthing resistance has to be addressed. The exclusion of field joints introduces a discrepancy in the core voltage along the cable length and the frequency-dependent impedance.
Simplification of the cable model within an electromagnetic transient (EMT) platform, whilst retaining a representative frequency-dependent behaviour, has been demonstrated as adequate. Modelling suggests a minimum impact of submersion depth on the cable characteristics. Furthermore, the potential for harvesting energy at the field joints is to be explored.
Benefits
Singapore’s Carbon Footprint
Fossil fuels dominate power generation in Southeast Asia. Amongst the eleven Southeast Asian countries, the combined annual electricity consumption of Indonesia, Malaysia and Singapore represents about 50% of SEA power consumption, and these three countries are responsible for 57% of CO2 emissions from the SEA power generation system. The power generation system in Singapore is almost exclusively reliant on natural gas, with 95% of electricity produced coming from gas-fired plants [7].
Singapore has very limited renewable energy resources available. Located within the intertropical convergence zone, Singapore is characterised by a relatively windless and cloudy weather regime that effectively precludes wind energy and offers only moderate solar potential that is ostensibly limited to small-scale rooftop solutions due to the city-state’s land scarcity (that said, some marginal floating solar farms have been developed on inland water reservoirs). Although natural gas is the cleanest fossil fuel, power generated exclusively with gas-fired plants remains a high-carbon content source.
An alternative to reduce carbon emissions could be to import electricity or fuels produced from low-carbon renewable resources from other countries. Solar PV farms in Australian NT are supposed to supply 20% of Singapore’s electricity demand. Over the last few months, Singapore has actually increased their load forecasts quite significantly — so it’s probably getting closer to up to 15 per cent [8].
The emissions of importing solar electricity into Singapore from Australia are just a fourth of electricity from natural gas CCGT plants (the primary source of electricity nowadays). If Singapore imported a fifth of its electricity needs through this project, the total annual emission savings would be 4.3 Mt CO2 eq. If we ignored the embedded emissions and accounted only for direct emissions, then the savings would be 5.2 Mt CO2 eq [4]. This is about 10% of the current annual GHG emissions of Singapore.
Accelerating the Path Towards The Energy Transition
The Indo-Pacific region is undergoing a massive energy shift, and the proportion of energy delivered by electricity is increasing significantly. Energy demand in Southeast Asia is expected to increase by 60% by 2040, expanding at an average rate of 6% annually. Due to its low cost, demand for renewable electricity is rising.
Australia has the second-largest solar resource per person in the world and the highest in the G20. Large-scale renewable energy exports present a rare chance to meet local energy needs and maintain economic growth.
Figure 4. Singapore is greening its power sector because it makes up a significant portion of the country’s overall emissions. Source: https://unsplash.com/es/fotos/-8juRlGCr5c
Mean global temperatures and sea levels are increasing together with the glasshouse gases in the earth’s atmosphere. Societies are attempting to switch to renewable energy sources that don’t emit carbon. Sun Cable proclaims that their environmental studies will look not only for ways to avoid and minimise impacts to the environment and heritage values but also GHG emissions during construction.
The development of the AAPowerLink project will position Singapore, Australia, and other Asian nations as regional renewable energy hubs and create significant economic and sustainable energy opportunities for decades. It will create thousands of construction and operational jobs, stimulating local opportunities for businesses and suppliers. The AAPowerLink is an AUD 30+ billion project.
Financial Benefits
Sun Cable’s Australia/Singapore power link has been recognised with major project status due to its likely significant contribution to regional economic development. This $20-30 billion project near Tennant Creek includes provisions for a 10 GW solar farm and 20-30 GWh storage facility. It’s the world’s largest solar farm under development and could create up to 1000 jobs during construction and 300 ongoing jobs once it’s fully operational [9].
The most recent agreement, according to executives, serves as a roadmap for the project’s “financial closure” phase and outlines how the company will cooperate with and address any concerns with the NT Government.
A 10-gigawatt solar farm and battery are part of Sun Cable’s AUD 30 billion projects at a far-off pastoral ranch. If there were a demand, the project could send 800 megawatts of electricity into the Darwin-Katherine system. That represents a significant boost in the region’s electricity supply, enabling the emergence of new sectors, particularly for Darwin. An expanded supply would be in line with the NT Government’s efforts to develop industries at Middle Arm, including processing chemicals and minerals and manufacturing hydrogen.
All of those new industries require competitively priced, stable, very reliable electricity supply in very large volumes — this project is a critical element in making that happen. Besides, the coronavirus pandemic has had little impact on Sun Cable’s plans and ability to access finance.
References
[1] Sun Cable
[2] 17-20 GW fotovoltaicos y 36-42 GWh, los datos del proyecto de Sun Cable en Australia
[3] June 2022 Infrastructure Priority List update
[4] Ramachandran, S., Siala, K., de la Rua, C., Massier, T., Ahmed, A., & Hamacher, T. Life cycle impacts of a cost-optimal HVDC connection to import solar energy from Australia to Singapore.
[5] Ardelean, M.; Minnebo, P. HVDC Submarine Power Cables in the World; Technical Report EUR 27527 EN; Joint Research Centre, The European Commission: Den Haag, The Netherlands, 2015.
[6] Schipper, J., Sim, S., Dang, Q., & Mukhedkar, R. (2021). REPRESENTATIVE MODELLING OF VERY LONG HVDC CABLES.
[7] Power Generation
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