From: Michael V
ID: 1499094
Subject: re: February Chat

*The Minerals Council NT is supporting Sun Cable’s $20 billion solar farm proposal in the Barkly *The majority of solar panels are made in Asia, but the Minerals Council believes they could be made in Australia using raw materials from the NT *The solar farm would cover 15,000 hectares and require 22 million solar panels and a power line all the way to Singapore
https://www.abc.net.au/news/rural/2020-02-11/nt-mining-sector-backing-barkly-solar-farm-proposal/11951566

Looks like someone has taken up dv’s idea.

——

From: Tamb
ID: 1499095
Subject: re: February Chat

How will they minimise transmission losses?

——

From: Woodie
ID: 1499096
Subject: re: February Chat

hmmmm…… some rounded sums. $20 bill. 20 mil solar panels. That’s $1000 per panel. You can buy ‘em here for $139 each. They’re gettin’ ripped off, man.

——

From: sarahs mum
ID: 1499097
Subject: re: February Chat

The transmission line between Tassie and Vic cost a motza. And it is no where near as far..

——

From: Michael V
ID: 1499116
Subject: re: February Chat

looks around

dv?

sibeen?

The local experts appear to be missing in action.
.

——

From: dv
ID: 1499163
Subject: re: February Chat

I don’t have details on this project other than what is publicly available.

Currently the longest HVDC lines in the world are a little over 1000 km long (in China, duh).

A line from NT to Singapore would be at least 4000 km long. It’s not that it would be impossible: If “money is no object” you can engineer a fat enough copper or steel pipe to allow acceptable losses on a HVDC line sending 10 GW to Singapore. Anything is possible on paper, but the costs would be ridiculous. Conceivably they could use staged storage, but again you’re incurring losses at each stage.

OTTOMH I would think it would be more efficient and cheaper to do it some other way. I’m not very bullish on the Hydrogen Economy but it might even be cheaper to use the electricity to generate methanol or hydrocarbons (ask me how!) at site and pipe it Darwin to be sent to Singapore. Or, heavens, even use it to turn NT into a manufacturing powerhouse…

But I’d be very interested to hear how they plan to feasibly send this amount of electrical power on “a power line all the way to Singapore.”

——

Date: 11/02/2020 15:10:00
From: Tamb
ID: 1499167
Subject: re: February Chat

My sediments perzackly.

——

From: furious
ID: 1499169
Subject: re: February Chat

Singapore power retailer backs Cannon-Brookes’ $20 billion Sun Cable

“Sun Cable, which aims to meet one-fifth of Singapore’s electricity supply, has not yet gone public on the economics of the project, which would use a high-voltage direct current cable to reduce transmission losses.”

They don’t explain their mechanism for reducing loss. Does DC have less transmission loss than AC?

——

From: roughbarked
ID: 1499172
Subject: re: February Chat

DC is used in extra high (EHV) and ultra high (UHV) power transmission (500,000V and up) for the following reasons:

It is asynchronous. That is, becuase DC has no frequency, it can be used to connect two differnent systems without worrying about having to synchronize the systems.

The DC connection is a open circuit to AC systems. This is important when it comes to system stability-having that isolation helps to separate two separate systems in the event of a electrical fault event, such as lightning or equipment failure. The DC circuit limits the fault’s path, essentially protecting the unfaulted part of the system it is connected to.

For long distances, it is more economical. DC transmission towers take up less space which means less land can be used for right of way. Since DC only needs two poles at a maximum (sometimes one pole is used, and the ground is used as a return), less wire is needed. Towers are also more economical since they dont’ have to carry three separate wires.

Fewer losses. With a DC system, there are fewer losses—there is no reactive component to a DC circuit, so AC system- related losses like capacitive, inductive and skin effect are nonexistent. Again because there is no AC, losses and other issues associated with electrical coupling/induced currents are not an issue. There are only resistive losses as opposed to AC, which has reactive and resistive losses.

Easy to transfer large blocks of power. With DC, direction of power can be switched easier. This makes DC indispensable for areas where summer loadings and winter loadings are opposite-for example a state that is cooler in winter in one area and warmer in summer in another area. The DC circuit could be used to export power to the colder region in the winter from the warmer region, and from the cooler region to the warmer region in summer. Inverters are used to change the direction of power instantanously, as well as the amount of power transmitted.

The disadvantages are:

Cost. DC installations are very expensive, which is one reason why they don’t really get used below transmission voltage level. A DC substation requires more equipment than an AC substation would require, partially becuase the conversion process requires equipment that will eliminate harmonics that are created. This is very inefficient for subtransmission and tranmission voltages below 500kV (500,000V).

AC power is easier to step up and down. There is no such thing as a DC transformer, since transfomers require an alternating magnetic field to work. DC current, since there is no frequency, cannot produce the induced current in the secondary coil of the transformer. Transformation is an essential part of the AC power system, so this inability is a very significant negative.

Because of the disadvantages, DC transmission in the US is still not common it is very limited in scope, and is not generally used for voltages below 500kV. But in Europe it is decidedly more common. The asynchronous nature, as well as the particular areas, make DC connections a more suitable choice there than here in the US.

https://www.quora.com/When-and-why-is-DC-used-instead-of-AC-for-long-distance-electric-power-lines-Is-DC-becoming-more-common-now-What-are-its-advantages-and-disadvantages

——

furious said:

furious said:

Singapore power retailer backs Cannon-Brookes’ $20 billion Sun Cable

“Sun Cable, which aims to meet one-fifth of Singapore’s electricity supply, has not yet gone public on the economics of the project, which would use a high-voltage direct current cable to reduce transmission losses.”

They don’t explain their mechanism for reducing loss. Does DC have less transmission loss than AC?

Apparently, yes…

Electric power transmission – Losses

“As of 1980, the longest cost-effective distance for direct-current transmission was determined to be 7,000 kilometres (4,300 miles). For alternating current it was 4,000 kilometres (2,500 miles), though all transmission lines in use today are substantially shorter than this.”

From:

Present limits of very long distance transmission systems

I look at their website and think financial scam. At least they’re not claiming that they can produce 3 GWh of power, which they did on the original version.

sibeen said:

I look at their website and think financial scam. At least they’re not claiming that they can produce 3 GWh of power, which they did on the original version.

You’re probably right, but it is possible they have a good technical department and a separate marketing department who don’t bother to get their stuff reviewed.

But it does sound a bit like the solar tower scheme that went public, re-distributed $100 million or so, and was never heard of again.

The Rev Dodgson said:

sibeen said:

I look at their website and think financial scam. At least they’re not claiming that they can produce 3 GWh of power, which they did on the original version.

You’re probably right, but it is possible they have a good technical department and a separate marketing department who don’t bother to get their stuff reviewed.

But it does sound a bit like the solar tower scheme that went public, re-distributed $100 million or so, and was never heard of again.

hopefully same thing happens to our federal government

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

you mean like Saudi Arabia and other friendly neighbours around there fair point

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

The Rev Dodgson said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I wouldn’t go sticking your tongue across the terminals to see if there’s any charge left in it.

Peak Warming Man said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

The Rev Dodgson said:

Peak Warming Man said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

heavy nuclei existed before light nuclei ¿ ¿¿

The Rev Dodgson said:

Peak Warming Man said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

And you try and telly the young’uns that today and they wont believe you.

The Rev Dodgson said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

party_pants said:

The Rev Dodgson said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

Haven’t they got a set or two of those things in South Australia?

Michael V said:

party_pants said:

The Rev Dodgson said:

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

Haven’t they got a set or two of those things in South Australia?

I thought that was just for smoothing out the fluctuations in the grid and short term stuff. Not for storing charge during the day to power the grid at night for hours on end.

SCIENCE said:

The Rev Dodgson said:

Peak Warming Man said:

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

heavy nuclei existed before light nuclei ¿ ¿¿

What about electricity derived from hot springs

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

Michael V said:

party_pants said:

The Rev Dodgson said:

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

Haven’t they got a set or two of those things in South Australia?

that was never gunna work remember

Cymek said:

SCIENCE said:

The Rev Dodgson said:

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

heavy nuclei existed before light nuclei ¿ ¿¿

What about electricity derived from hot springs

lol

furious said:

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

or hydrocarbon like Cue 8 does it

oh wait

furious said:

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

I don’t think that would work. Hydrogen needs to be kept much colder than LNG. Plus hydrogen reacts with steel and makes it brittle. Not a great thing for a ship.

party_pants said:

Michael V said:

party_pants said:

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

Haven’t they got a set or two of those things in South Australia?

I thought that was just for smoothing out the fluctuations in the grid and short term stuff. Not for storing charge during the day to power the grid at night for hours on end.

Thy sort of are huge batteries the size of a Bunnings. (Or rather a large array of batteries much bigger than a Bunnings.)

furious said:

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

That’d be the way.

party_pants said:

furious said:

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

I don’t think that would work. Hydrogen needs to be kept much colder than LNG. Plus hydrogen reacts with steel and makes it brittle. Not a great thing for a ship.

Well, line the tanks with NotSteel^tm…

Maybe we could have a fleet of airships. Sail them laden with hydrogen the SIngers, deflate them and store the gas, send the empties back to Aus by ship for a refill.

The Rev Dodgson said:

Peak Warming Man said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

SCIENCE said:

The Rev Dodgson said:

Peak Warming Man said:

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

heavy nuclei existed before light nuclei ¿ ¿¿

I don’t get your point.

party_pants said:

The Rev Dodgson said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

OK, the system I worked on a few years ago used battery packs that were L 1321 x W 966 x H 2185 with a weight of 1720 kg and had an energy capacity of approximately 100 kWh. From what I have read they capacity for the battery pack has basically doubled without any increase in the dimensions.

That’ll give a starting point.

party_pants said:

Maybe we could have a fleet of airships. Sail them laden with hydrogen the SIngers, deflate them and store the gas, send the empties back to Aus by ship for a refill.

LOL

:)

ChrispenEvan said:

The Rev Dodgson said:

Peak Warming Man said:

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

Probably in China, like just about everything else.

Cymek said:

SCIENCE said:

The Rev Dodgson said:

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

heavy nuclei existed before light nuclei ¿ ¿¿

What about electricity derived from hot springs

OK, other than nuclear fusion and hot springs.

and tidal

and whatever else I didn’t think of.

furious said:

party_pants said:

furious said:

• I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge

Why not a gas tanker filled with hydrogen?

I don’t think that would work. Hydrogen needs to be kept much colder than LNG. Plus hydrogen reacts with steel and makes it brittle. Not a great thing for a ship.

Well, line the tanks with NotSteel^tm…

thats the beauty of it we now make steel with hydrogen not coal

party_pants said:

Maybe we could have a fleet of airships. Sail them laden with hydrogen the SIngers, deflate them and store the gas, send the empties back to Aus by ship for a refill.

Oh, the humanity.

ChrispenEvan said:

The Rev Dodgson said:

Peak Warming Man said:

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

Ah, I guess that was SCIENCE“s point too.

The Rev Dodgson said:

ChrispenEvan said:

The Rev Dodgson said:

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

Ah, I guess that was SCIENCE“s point too.

in the end all power is from gravity.

ChrispenEvan said:

The Rev Dodgson said:

Peak Warming Man said:

Yes that’s the way to go, it’s cheap in the short term but that’s all need what with fusion power just round the corner.

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

thats what we said

ChrispenEvan said:

The Rev Dodgson said:

ChrispenEvan said:

and where was the uranium made?

Ah, I guess that was SCIENCE“s point too.

in the end all power is from gravity.

we’re GUTted

SCIENCE said:

ChrispenEvan said:

The Rev Dodgson said:

All electricity other than from the old fashioned nuclear fission plants comes from nuclear fusion.

and where was the uranium made?

thats what we said

people believe me though.

sibeen said:

party_pants said:

The Rev Dodgson said:

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

OK, the system I worked on a few years ago used battery packs that were L 1321 x W 966 x H 2185 with a weight of 1720 kg and had an energy capacity of approximately 100 kWh. From what I have read they capacity for the battery pack has basically doubled without any increase in the dimensions.

That’ll give a starting point.

So we could fit 8 in a 6m (20foot) container. That’s 800kWh of the old batteries or 1600 if they are twice that now.
A New Panamax sized container ship can carry around 13,000 twenty footers.

That would give us 19,500,000 kWh. (let’s call it 20 million as a nice round number because we are not restricted by the Panana dimensions)

How long would that power the Singapore grid?

party_pants said:

sibeen said:

party_pants said:

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

OK, the system I worked on a few years ago used battery packs that were L 1321 x W 966 x H 2185 with a weight of 1720 kg and had an energy capacity of approximately 100 kWh. From what I have read they capacity for the battery pack has basically doubled without any increase in the dimensions.

That’ll give a starting point.

So we could fit 8 in a 6m (20foot) container. That’s 800kWh of the old batteries or 1600 if they are twice that now.
A New Panamax sized container ship can carry around 13,000 twenty footers.

That would give us 19,500,000 kWh. (let’s call it 20 million as a nice round number because we are not restricted by the Panana dimensions)

How long would that power the Singapore grid?

What weight is that? Could a Panamax carry all that mass?

Michael V said:

party_pants said:

sibeen said:

OK, the system I worked on a few years ago used battery packs that were L 1321 x W 966 x H 2185 with a weight of 1720 kg and had an energy capacity of approximately 100 kWh. From what I have read they capacity for the battery pack has basically doubled without any increase in the dimensions.

That’ll give a starting point.

So we could fit 8 in a 6m (20foot) container. That’s 800kWh of the old batteries or 1600 if they are twice that now.
A New Panamax sized container ship can carry around 13,000 twenty footers.

That would give us 19,500,000 kWh. (let’s call it 20 million as a nice round number because we are not restricted by the Panana dimensions)

How long would that power the Singapore grid?

What weight is that? Could a Panamax carry all that mass?

It would be 204,800 tonnes if you allowed 2.2 tonnes per container.

So a bit more than a NP ship, but still well in the range of a bulk carrier or oil tanker.

party_pants said:

Michael V said:

party_pants said:

So we could fit 8 in a 6m (20foot) container. That’s 800kWh of the old batteries or 1600 if they are twice that now.
A New Panamax sized container ship can carry around 13,000 twenty footers.

That would give us 19,500,000 kWh. (let’s call it 20 million as a nice round number because we are not restricted by the Panana dimensions)

How long would that power the Singapore grid?

What weight is that? Could a Panamax carry all that mass?

It would be 204,800 tonnes if you allowed 2.2 tonnes per container.

So a bit more than a NP ship, but still well in the range of a bulk carrier or oil tanker.

Then all you’d need, to make it carbon neutral, is to make the ship nuclear powered. Or they could cut out the middleman and build a nuclear power station in singapore…

furious said:

party_pants said:

Michael V said:

What weight is that? Could a Panamax carry all that mass?

It would be 204,800 tonnes if you allowed 2.2 tonnes per container.

So a bit more than a NP ship, but still well in the range of a bulk carrier or oil tanker.

Then all you’d need, to make it carbon neutral, is to make the ship nuclear powered. Or they could cut out the middleman and build a nuclear power station in singapore…

It would run electric motors off the battery. Obviously it could not discharge fully at the destination, it would have to retain enough charge to sail back the return journey.

I wonder if a fully charged ship would weigh more than one that was discharged.

party_pants said:

I wonder if a fully charged ship would weigh more than one that was discharged.

Someone could be probably work that out, might cost you, they may

party_pants said:

I wonder if a fully charged ship would weigh more than one that was discharged.

yes, it would.

• I wonder if a fully charged ship would weigh more than one that was discharged.

According to the calculations here:

Does the mass of a battery change when charged/discharged?

Your 19,500,000 kWh would have

19,500,000 × 1000 × 3600 / 10¹⁷ kg weight difference…

Which is 761mg…

furious said:

• I wonder if a fully charged ship would weigh more than one that was discharged.

According to the calculations here:

Does the mass of a battery change when charged/discharged?

Your 19,500,000 kWh would have

19,500,000 × 1000 × 3600 / 10¹⁷ kg weight difference…

Which is 761mg…

702mg – I got my six upside down…

furious said:

• I wonder if a fully charged ship would weigh more than one that was discharged.

According to the calculations here:

Does the mass of a battery change when charged/discharged?

Your 19,500,000 kWh would have

19,500,000 × 1000 × 3600 / 10¹⁷ kg weight difference…

Which is 761mg…

LOL. Three quarters of a gram in 205,000 Tonnes.

Anyway, 20 GWh is probably a bit too small to be useful.

Singapore’s annual electricity consumption in 2018 was 49.6 TWh, which works out to about 135 GWh per day.

This works out to about 6.8 ships per day at this size.

Probably need to be looking at 100 GWh per ship to make a useful energy transport system.

Transmission line costs killed the hot rock Cooper project. The cost of connecting it to the distant grid in NSW.

That and the drill bit sticking.

To highlight the problem somewhat …

For a given conductor, a given power requirement, a given acceptable loss and a given voltage, the amount of material required goes up as the square of distance, not linearly. It tends to rise faster with distance than other costs.

Consider a simple conductor with a cross-sectional area A, resistivity r, length L. Resistance will be R = r * L / A. Total mass will be M = A * L * rho, where rho is density.

Suppose the input power is P and acceptable loss fraction is f, so that actual power loss is p = P * f. Operating voltage is V.

That loss will be p = V ² / R.

So find M in terms of L.

V ² / p = r * L / A

M = p * r * L ² * rho / V ²

EEs prefer the losses to be expressed as I²r.

sibeen said:

EEs prefer the losses to be expressed as I²r.

ah well it was the R that mattered

dv said:

To highlight the problem somewhat …

For a given conductor, a given power requirement, a given acceptable loss and a given voltage, the amount of material required goes up as the square of distance, not linearly. It tends to rise faster with distance than other costs.

Consider a simple conductor with a cross-sectional area A, resistivity r, length L. Resistance will be R = r * L / A. Total mass will be M = A * L * rho, where rho is density.

Suppose the input power is P and acceptable loss fraction is f, so that actual power loss is p = P * f. Operating voltage is V.

That loss will be p = V ² / R.

So find M in terms of L.

V ² / p = r * L / A

M = p * r * L ² * rho / V ²

imagine how much worse it would be if we were skinning with AC

sibeen said:

EEs prefer the losses to be expressed as I²r.

cough

R

cough

party_pants said:

The Rev Dodgson said:

party_pants said:

I still like the idea of charging a very large battery on board a ship the size of a bulk carrier, and then sailing it off to Singapore, where it can dock and slowly discharge its load before sailing back to Darwin for a recharge.

Same here.

I wonder how the money works out though.

And how much energy you can store in a big ship full of batteries.

I don’t know either. I wonder if anyone is really working on large scale non-portable batteries. Everyone seems to be fixated upon smaller and compact batteries for cars and trucks or off-grid tiny houses. Not heard much in the way of development of huge batteries say the size of a Bunnings that can be built on the outskirts of towns to connect to the grid.

The mob I am buying the batteries for my house from (48v, 400ahr lithiums) have a 10000ahr battery is the largest in their range (weighs a mere 250kg!) and you need 4 to make up a 12v battery- for my house, I’d need 4 tonnes of them (16 in series to make up the 48v)
but I’d only have to charge them once a month lol

sibeen said:

EEs prefer the losses to be expressed as I²r.

That’s fine, the result will still be that M is proportional to the square of L.

SCIENCE said:

dv said:

To highlight the problem somewhat …

For a given conductor, a given power requirement, a given acceptable loss and a given voltage, the amount of material required goes up as the square of distance, not linearly. It tends to rise faster with distance than other costs.

Consider a simple conductor with a cross-sectional area A, resistivity r, length L. Resistance will be R = r * L / A. Total mass will be M = A * L * rho, where rho is density.

Suppose the input power is P and acceptable loss fraction is f, so that actual power loss is p = P * f. Operating voltage is V.

That loss will be p = V ² / R.

So find M in terms of L.

V ² / p = r * L / A

M = p * r * L ² * rho / V ²

imagine how much worse it would be if we were skinning with AC

I’ll be lighting a candle on my Edison shrine

dv said:

sibeen said:

EEs prefer the losses to be expressed as I²r.

That’s fine, the result will still be that M is proportional to the square of L.

Oh, well aware of that, just trying to give some perspective. I²R is just the general way we talk about these losses.

sibeen said:

dv said:

sibeen said:

EEs prefer the losses to be expressed as I²r.

That’s fine, the result will still be that M is proportional to the square of L.

Oh, well aware of that, just trying to give some perspective. I²R is just the general way we talk about these losses.

Well good.
I wanted to also show the reason why they got for high voltages: the mass of conductor goes as the inverse square of the voltage.

dv said:

sibeen said:

dv said:

That’s fine, the result will still be that M is proportional to the square of L.

Oh, well aware of that, just trying to give some perspective. I²R is just the general way we talk about these losses.

Well good.
I wanted to also show the reason why they got for high voltages: the mass of conductor goes as the inverse square of the voltage.

China has installed some extremely high voltage DC power lines recently for long distance. Check web.

Australasia
Basslink is 400 kV DC (highest voltage in Australia).
Inter-Island is 350 kV DC (highest voltage in NZ)

China 800 kV DC for:
Xiangjiaba-Shanghai
Yunnan – Guangdong
Jinping – Sunan
Nuozhadu – Guangdong
Hami – Zhengzhou
Xiluodo – West Zhejiang
Humeng – Shandong
Irkutsk – Beijing (with Irkutsk being in Russia of course)
Jinsha River II – East China

China 1100 kV DC for:
Xinjiang – Anhui (currently under construction)

mollwollfumble said:

China has installed some extremely high voltage DC power lines recently for long distance. Check web.

Yeah that was my first comment

dv said:

sibeen said:

dv said:

That’s fine, the result will still be that M is proportional to the square of L.

Oh, well aware of that, just trying to give some perspective. I²R is just the general way we talk about these losses.

Well good.
I wanted to also show the reason why they got for high voltages: the mass of conductor goes as the inverse square of the voltage.

The reason that I²R losses are generally used is because it is reflective of the load for which the voltage isn’t.

sibeen said:

dv said:

sibeen said:

Oh, well aware of that, just trying to give some perspective. I²R is just the general way we talk about these losses.

Well good.
I wanted to also show the reason why they got for high voltages: the mass of conductor goes as the inverse square of the voltage.

The reason that I²R losses are generally used is because it is reflective of the load for which the voltage isn’t.

I understand.