Eskom vs Gautrain

[Chicken Boo]

It seems Eskom has recently begun load-shedding under the table. Recently, as we all know, the Gautrain began operating. Coincidence? Well who knows. However, it does seem pretty obvious that the train is going to put higher demands on electrical supply.
I would fully expect government, councils etc. to completely (possibly purposefully) overlook the impact of something like a high demand on an already overstrained system, but it doesn't seem unreasonable to think that the Gautrain might well be running at the expense of paying Eskom consumers sitting in the dark.

Best source I could find is: http://donnedwards.openaccess.co.za/2008/01/gautrain-doesnt-use-electricity-really.html

There are two Adtranz 250kW three-phase traction motors on each motor coach, with IGBT control.

That's not a small amount of power. The total requirement given on that page is 28MW.

According to the Gautrain page:

The power feed driving the trains is derived from two different Eskom sub-stations with built-in redundancy. Thus, if one Eskom feed goes down, the trains will remain fully operational.

All stations are supplied with backup generator capacity

Would it not perhaps be revealing for the Gautrain to be forced to run off its (purported) backup facilities (post-WC) and use Eskom as the backup?

 

[genetic]

Factories use more power than the Gautrain.

 

[Chicken Boo]

Factories use more power than the Gautrain.

Name one that came online in the last month.

 

[Nerfherder]

Also its winter... it makes more sense that the load shedding happened on the coldest day of the year.

Leave our train alone !

 

[genetic]

Name one that came online in the last month.

I can show you new power generating facilities that have come online in recent months.

At Gourikwa power station two more units have been added, each with 148MW capacity and five additional units at Ankerlig with capacities ranging between 148.3 and 149.2 MW were completed in March 2009.
http://www.eskom.co.za/live/content.php?Item_ID=5981

Koekenaap Wind Farm with a generating capacity of 100 - 200MW has come online in beginning of this year.
http://www.southafrica.info/about/sustainable/wind-030308.htm

 

[Chicken Boo]

I can show you new power generating facilities that have come online in recent months.

At Gourikwa power station two more units have been added, each with 148MW capacity and five additional units at Ankerlig with capacities ranging between 148.3 and 149.2 MW were completed in March 2009.
http://www.eskom.co.za/live/content.php?Item_ID=5981


Koekenaap Wind Farm with a generating capacity of 100 - 200MW has come online in beginning of this year.
http://www.southafrica.info/about/sustainable/wind-030308.htm

Ok, interesting.

 

[genetic]

I'm sure the Gautrain is such an asset to Gauteng, that the positive benefits completely outweigh the few negativities surrounding the entire project.

 

[ToAsTeD]

I'm sure the Gautrain is such an asset to Gauteng, that the positive benefits completely outweigh the few negativities surrounding the entire project.

+1

 

[Paul_S]

It seems Eskom has recently begun load-shedding under the table. Recently, as we all know, the Gautrain began operating. Coincidence? Well who knows. However, it does seem pretty obvious that the train is going to put higher demands on electrical supply.
Best source I could find is: http://donnedwards.openaccess.co.za/2008/01/gautrain-doesnt-use-electricity-really.html
That's not a small amount of power. The total requirement given on that page is 28MW.

The author is rather ignorant when it comes to physics.
The total power requirement of 28MW is if ALL the trains are accelerating as hard as they can at the same time.
Once a train is up too speed it will require a lot less power to keep it coasting along.
If a train is stationary it's going to be using very little electricity.
If a train is decelerating it's going to be generating power (25% of it's capacity from what I read).
Also factor in the stop times of the trains plus the fact that they don't run all night and you're probably looking at a very efficient way of moving a lot of people fast.
I'd be surprised if the train system used more than 30% of that 28MW at any given time but only the train engineers will be able provide exact figures.

If you own a BMW with a 250kW engine it may generate 250kW under hard acceleration but if you're cruising along at 160km/h it's not even going to be generating 100kW of power.
Steel wheels on steel rails have a much lower rolling resistance than a car's tyres on the road (typically 20 to 30 times less rolling resistance).
If someone can provide the aerodynamic drag coefficient, frontal area and rolling resistance we can work out how much power is required to move the train along at 160km/h.

 

[genetic]

The author is rather ignorant when it comes to physics.
The total power requirement of 28MW is if ALL the trains are accelerating as hard as they can at the same time.
Once a train is up too speed it will require a lot less power to keep it coasting along.
If a train is stationary it's going to be using very little electricity.
If a train is decelerating it's going to be generating power (25% of it's capacity from what I read).
Also factor in the stop times of the trains plus the fact that they don't run all night and you're probably looking at a very efficient way of moving a lot of people fast.
I'd be surprised if the train system used more than 30% of that 28MW at any given time but only the train engineers will be able provide exact figures.

If you own a BMW with a 250kW engine it may generate 250kW under hard acceleration but if you're cruising along at 160km/h it's not even going to be generating 100kW of power.
Steel wheels on steel rails have a much lower rolling resistance than a car's tyres on the road.

Added to that that there's roughly an extra 1,200MW of power generating capacity since March 2009. Even 28MW at peak is minuscule.

What we should be worried about is Eskom's reliability more than the Gautrain's toll on the national grid.