95% of Singapore's electricity comes from burning natural gas. They do not have many alternatives.
Not sure if you have heard, but Singapore is a small island. No room for sprawling solar
or wind farms. A few rooftop solar panels on residential buildings. That is about it.
But what if you were to pipe in the electricity from overseas?
The Australia-ASEAN Power Link is a mega-project
looking to bring renewable solar energy from Australia all the way to Singapore.
It is also referred to as the "Sun Cable", after the Singaporean company developing the project.
In this video, I want to dive into how this company intends to bring
clean solar power all the way to the Lion City.
As announced, the Sun Cable project proposes a ten gigawatt capacity
solar farm occupying 12,000 hectares in Australia's Northern Territory.
The solar panels would be prefabricated within the country and assembled on-site.
The generated electricity would first travel 500 miles (800 kilometers) to
the nearby city of Darwin, the largest in the area, and contribute to their renewable
energy goals. The rest would be exported to Singapore using an intercontinental
2,300 mile (3,700 kilometers) HVDC underwater power line. More on HVDC later.
To meet overnight demand, a battery system near the solar farm has been proposed.
It would store excess power for after sunset. This farm, with the battery storage,
is estimated to cost about $7 billion using current cost estimates.
The project is still in the planning stages, so details are subject to change.
But that is what we know. And it still sounds super cool.
But wait. How are we going to bring this electric power all the way from Australia to Singapore?
2,300 miles or 3,700 kilometers is almost the entire width of the continental United States!
Let us briefly talk about power transmission.
Electric current can come in two forms: Alternating Current
(AC) and Direct Current (DC). AC will flow in one direction for a period, and then reverse to the
other direction for the rest of the period. DC on the other hand, flows in one direction only.
Most of the systems we use today are AC systems.
The power is generated, transmitted, and consumed in AC. There are reasons for this.
You might have heard about the AC-DC wars and that Tesla and Westinghouse defeated
Thomas Edison to have AC become the standard used today. I think there is a movie about it.
Setting aside dramatic Hollywood conflicts, the generally accepted
reason why AC "beat" DC is that AC power transmission systems are more economical.
Power is often generated far away from where the consumer lives, so you have to transmit it
to them. But before you can do that, you use a transformer to first step up the voltage of the
electricity. The higher the voltage, the lower the energy losses we get during transmission.
Once it gets to the consumer we use step down transformers to
dial down the voltage to a level where it can be practically used.
AC transformers do all this more efficiently and affordably than equivalent DC equipment.
And that is why they dominate our systems today.
There is a catch though and it has to do with long distance transmission. High voltage AC
systems lose a lot of that efficiency the further away the power source is from the power consumer.
There are a number of reasons for this. But a big one is called the "skin effect".
What does that mean? It involves your cables. DC flows evenly throughout the
entire width of your cable. Alright, fair enough.
AC on the other hand, has a tendency to flow more densely at the surface of the cable and much less
so deeper beneath the surface. The result is increased resistance and thus power loss.
It is why you might frequently see multi-strand cables and coils in certain induction systems.
High Voltage Direct Current systems were developed and widely adopted to deal with this shortcoming.
While experiments in the space have existed since the 1880s, the first modern HVDC subsea
cable was implemented in 1954 in Sweden by the industrial multinational ABB.
It linked the island of Gotland with the Swedish mainland, a span of about 90 km.
Since then, the technology has rapidly developed.
How does it work? The main difference would be the inclusion of equipment to convert
AC power to DC power and vice versa: Converters and Inverters.
This equipment is expensive and complex, which adds to the overall initial cost. But in exchange,
we get substantially better economics when transmitting power across long distances.
It is sort of interesting how the dynamics play out. Let us
imagine a cost versus distance graph charting HVDC and HVAC.
The DC terminal cost is substantially higher than the AC terminal cost.
Like I said, complex converters and inverters need to be purchased and integrated into the system.
But the cost of the line rises faster with AC than DC the further out you get.
This is mostly due to the significantly faster rising energy losses of the line itself.
In fact, if you compare two 1,200 mile or 2,000 kilometer AC and DC
lines with the same high voltage, you find that the losses for the AC line
are twice as high as the DC line even if it were to carry half the power.
DC costs more than AC in short distances like as I said before.
But at the "breakeven distance", roughly about 62 miles or 100 kilometers, DC overtakes AC.
Assuming that electrical losses for HVDC cable are about 3% per 1,000 kilometers,
the Sun Cable's 3,200 kilometers is estimated to will have about 10% electrical loss in total. An
equivalent HVAC line is likely to have over twice that - a substantial disadvantage.
Without HVDC, a lot of renewable energy sources like offshore wind or hydro would not be so
economically tenable. The Three Gorges Dam for instance uses three overhead HVDC lines
to transport electricity 600 miles or 1,000 kilometers to Guangzhou and Changzhou.
It is perfect for undersea infrastructure, where intermediate substations are not practical.
There exists over 6,000 miles or 10,000 kilometers of subsea HVDC lines
connecting power sources and consumers. 70% of those subsea cables are in Europe,
but there are a few notables around the world.
In fact, there is already one in Australia connecting the island of Tasmania to the
state of Victoria: Basslink. 230 miles or 370 kilometers long,
it is, interestingly enough, owned by a company in Singapore. More on this one later.
So we walked a bit through the technology.
Let us look at the challenges of actually implementing it across 2,300 miles of seabed.
When laying subsea cables, you have two rules of thumb:
One. You want to keep the overall length of the cable as short as possible,
because longer cables cost money to make and maintain.
And two, you want to avoid big deep trenches and steep slopes. This is self explanatory. Sharks.
Most existing subsea power cables have been laid in relatively shallow depths (under
0.6 miles or 1 kilometer) and on flat-bottomed seas with thick silty, sandy, pebbled sediments.
Unfortunately that will not be the case here.
Australia is surrounded by steep slopes and deep water.
As of this writing, the finalized route has not
yet been provided but we have a good idea of where it will go.
The most economical and technically practical route would first start
from Darwin and go across the Timor sea south of East Timor to Indonesia.
Then, it would pass through Indonesia either between the islands of Bali and Lombok
(or Lombok and Sumbawa) and enter the Java sea.
Then finally it runs up the Java sea until you get to Singapore at the Changi area.
For the most part, the proposed route would be quite shallow, less than 600 feet or 200
meters deep. But a 700 mile (1,200 kilometer) long section south of East Timor at the Timor trough
would see waters over a mile deep. This is a major challenge.
It has been done before. The SA.PE.I cable from Sardinia to the Italian mainland, the deepest
subsea power cable in the world, got to similar depths. But special attention would be required.
For instance, the SA.PE.I's deepwater cables were made of aluminum rather
than the more traditional copper. Aluminum is cheaper and more plentiful than copper.
But it is not as good at conducting electricity - so that maybe is a wash.
But since aluminum cable is also lighter than copper, you can carry and lay more
of it from your Cable Laying Vessel. Running deep water ships is expensive
and time consuming so you do not want to have to do more of it than you need to.
Back to the Sun Cable. For the shallow bits, the most significant factor to consider is potential
interference. The Java Sea and Singapore Strait are some of the busiest water ways in the world.
The Java sea already has a bunch of pipelines, fishing trawlers, and communication cables
cris-crossing it. And the Singapore Strait has thousands of ships passing through each year.
For these busy areas, engineers will likely have to trench or bury the cable some 2-5 feet
(0.6-1.5 meters) deep to protect the cable from being dredged up by fishing nets
or damaged by boat anchors and other dropped things. Such things can cause blackouts
from cable damage and trigger liability clauses in service operating agreements.
Finally, a bigger problem than laying the cable is getting it in the first place. The
HVDC cable manufacturing world is pretty niche, the product is complex, and the output is slow.
The Sun Cable as currently proposed uses two cables of 3,200 kilometers each.
More than the total annual output of all the HVDC cable manufacturers in Europe.
So additional money and time (a span of 3-5 years) needs to be set aside
to build up capacity from multiple manufacturers
all over the world. Speaking of money ... how are they going to pay for all this?
The subsea cable portion of the entire Sun Cable project is projected to cost
about $5.6 billion USD before insurance and administrative expenses. The majority of that,
$4.6 billion, goes to getting the cable itself.
That is over 6x the cost of the aforementioned Australian HVDC cable Basslink,
which cost $670 million USD.
The Sun Cable installation costs alone would be greater than the entire Basslink project.
When also taking into account the cost of the solar farm,
the whole thing is likely to run beyond the $10 billion USD mark.
Seed funding for the privately-owned Sun Cable corporation has come from an unlikely pair of
Australian billionaires. One is the founder of Atlassian and the other former CEO of Fortescue
metals. But I don't think that they are rich enough to fund the whole thing themselves.
What will likely need to happen is some sort of multi-decade service agreement between the company
and the entity purchasing the power. For instance, Basslink derives its cash flows
from a 25-year service agreement with the Tasmanian energy utility Hydro Tasmania.
That allowed them to raise private money to eventually do the project. Those private
investors would undoubtedly be attracted to the regular dividends coming from such a project.
Side note. Basslink can offer a couple lessons that Sun Cable can learn. Less than ten years
after its 2006 commissioning, Basslink suffered a brutal outage. It took six months to repair
the cable amid roiling seas. Hydro Tasmania was pissed and took them to arbitration.
The arbiter found Basslink to be at fault and in 2020 fined them $30 million USD.
Short of what Hydro had wanted, but it still is a disappointing outcome for Basslink investors.
The whole kerfuffle was so bad that I think that cash shortages forced the company into
a technical default. This delayed it in fixing yet another 2-month outage in 2018.
I hope the Sun Cable people can learn from those incidents and try to avoid those mistakes.
Considering how these big-name lowest-bid contracts tend to end up, it makes me wonder
about the feasibility of doing infrastructure like this using these public-private type partnerships.
The megaproject's sheer size and immense cost make it likely that they break up the
thing into multiple chunks and milestones over many years. But once fully deployed,
the Cable will provide up to 20% of Singapore's energy needs. That is great for them.
But the opportunity spreads far beyond just Singapore. From 2015 to 2040, energy demand
from the Southeast Asian countries is estimated to expand 65%. Almost all of it from fossil
fuels unless otherwise. There’s ample demand for clean energy. Indonesia might sign on to receive
that electricity before Singapore. After all, the cable passes through their waters first.
There is a lot to gain for Australia as well. The country's current economy
is heavily dependent on mining, petroleum, and exports of platypuses. The Aussies have gotten
rich off of these vast reserves, but it does not help with the whole global climate change thing.
Australia has more to offer than its carbon and wallabies. Its Northern Territory is larger than
Egypt but has less than 250,000 people as compared to Egypt's 103 million. It is also one of the most
solar irradiated areas in the world, offering tantalizing renewable energy possibilities.
For Australia, the Sun Cable explores a new and exciting energy export paradigm.
It will help cement better relationships with the Southeast Asian countries. And it will
help wean the country off its uncomfortable dependence on certain exports to certain areas.
According to Wikipedia, the project is scheduled to come online some time in 2027. 2027!
That year feels like something out of science fiction. But alas,
less than a decade away. I am looking forward to following its progress and seeing it come alive.
Thanks for watching. And full credit to Asianometry viewer shazmosushi for
suggesting this topic. If you liked this video, please consider subscribing. If
you have any ideas or suggestions for future videos, let me know!