It’s a small country with a big problem.
Singapore set itself an ambitious goal of achieving net-zero emissions during
the second half of the century, but as it stands 96% of its energy comes from burning
natural gas and there are few alternatives to providing energy for its 5.7 million residents.
To fix this there are now plans to build the world’s largest solar array in the Australian
outback and then connect the two nations by a nearly 4,000-kilometre undersea cable.
Set to cost AUD $23 BN and create an entirely new export industry in the region,
this megaproject is just the beginning for South East Asia’s energy revolution.
Despite being highly developed, Singapore was
always going to struggle with its transition to renewable energy.
It’s one of the world’s smallest countries and the island nation lacks the wide-open
space needed for solar arrays. There aren’t suitable rivers for harnessing hydropower.
Low average wind speeds and Singapore’s location along one of the world’s busiest and narrowest
shipping lanes rules out offshore wind farms - and geothermal energy sources are non-existent.
Still, it has a nice Apple store and a funky looking hotel with what’s probably the world’s
most awesome pool. Anyway, let's get back to its geographic shortcomings.
To get around the problems, the Australian-Singaporean company Sun Cable
is planning to make use of the abundant solar potential in one of the world’s most
arid and least-populated regions to provide clean energy for one
of the world’s most densely populated countries.
The Australian-ASEAN Power Link - or simply “Sun Cable” as it’s known in
media circles - will be a massive solar farm covering more than 120 square kilometres
and generating 14-gigawatts of energy in the heart of Australia’s Northern Territory.
That energy will then be stored in a 33 GWh capacity battery,
before travelling over 750 kilometres to Darwin using high-voltage overhead lines then a further
3,750 kilometres via undersea high-voltage direct current (HVDC) transmission cables
to eventually provide 20% of Singapore’s energy needs.
With 4,500 kilometres separating Singapore from its future energy source
the obvious questions are what were they thinking and why Australia?
Well, while Singapore is surrounded by other, much closer, countries
none of them can match what the Australian outback has to offer.
Yeah, it’s not like that.
Located just outside the tropics in one of the driest and most solar irradiated areas on Earth,
the outback provides much greater and more reliable energy potential than
Singapore’s neighbours, which experience quite a few more rainy days each year.
Now, as you might expect, transmitting electricity over long distances - like
that patch of ocean between Australia and Singapore - does result in losses,
but this isn’t a new issue and we have known how to solve it since the 1950s.
You’ll remember from school that by converting alternating current (AC) power to direct current
(DC) power, resistance within the cable is minimised and allows electricity to be
transmitted over much greater distances with less loss, no doubt it's all coming back to you now.
Using High-Voltage Direct-Current cables (HVDC) and converters and
inverters at either end to make the power usable,
electrical losses over the entire length of the Sun Cable will only add up to around 10%.
That’s considered an acceptable loss given that its generation was emission-free and it’s a feat
that was proven feasible in 2019 when China opened the 3,293-kilometre ultra-high-voltage line.
With its undersea section stretching for over 3,750 kilometres - depending on the
final route - the Sun Cable will be at least six times longer than the world’s current
longest underwater HDVC, that's the NorNed linking Norway and the Netherlands, and five times
longer the Viking Link that's currently under construction and set to connect Denmark to the UK.
While the undersea part of the journey perhaps presents the biggest challenge for the project
it isn’t unachievable due to the Indonesian archipelago once being a single landmass,
back during the last ice age when we last left our homes and went to nightclubs.
The Java and Southern South China Seas are both relatively shallow,
with depths rarely exceeding 100 metres. It’s only the Timor Sea that’s a serious
obstacle with sections that drop down to 1,700 metres.
As it stands today the deepest HVDC cable sits at a depth of 1,600 metres between
Italy and Sardinia, but Italian cable manufacturer
Prysmian is developing technology that can lay cables as deep as 3,000 metres.
Though large-scale projects like this often clash with environmental and indigenous groups,
the Sun Cable team has worked alongside government agencies since the project was first proposed
and has even shifted the site of the solar array to avoid building on indigenous land.
The project is outrageously ambitious and it
might seem pretty far fetched when you first hear about it.
But those involved aren’t messing around. The project was added to Infrastructure Australia’s
Priority List and agreements with the Northern Territory Government were signed in early 2021.
Subsea surveying started in 2020 and 750-kilometres of the route have now
been fully mapped. Construction is due to start in 2023, the system will begin operating in 2026
and it’ll be connected to Singapore in 2027.
With ample room for future growth, a host of developing nations on its
doorstep and the demand for clean energy only set to rise, the Sun Cable project sets
Australia up to transition from the world’s largest exporter of coal
to a green energy exporting superpower – and it could act as a model for other regions with
similar conditions to maximise their energy production and provide for a growing world.
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