Solar generation is now cheaper than coal — How it happened

[Utterly Confused]

When the payback period for residential solar and storage is about 7 years, I suspect the large scale plants will also do better.

And frankly the "base load" generator argument is a bit of a strawman. The grid always has to match supply with demand - baseload just meant supply was fixed whilst demand was variable. Now both are variable - we can engineer our way out of it. From storage to time-of-day tariffs to shift demand. I think the future is bright!

Tell the corrupt cANCer that.

 

[Danie_V]

"The cost of electricity from coal dropped $2 (R31) per MWh between 2009 and 2019" - so why is our electricity costs shooting up so much in SA!!!!

Yes point of having a grid is to mix inputs from various sources of energy generation including solar, wind, pumped storage/batteries/thermal, nuclear, etc. But it does also mean using a 100-year-old grid is not really going to achieve that well - we should be updating the grid side too. EU has been testing also tapping into fleets of EVs that have battery storage available which they sell back to the grid when used.

 

[mypetcow]

This is absolute the future, except in the mind of our Energy Minister. However to apples with apples one do need to include the battery cost as well.

I just think it would make so much sense for towns to have their own solar, wind and battery farms.

I’m afraid you are misinformed. The amount of energy that needs to be stored to power anything like a town for any amount of reasonable time is insanely huge. Keep in mind that any old power station in Mpumalanga goes through about 600 tons of coal per hour every hour of the day and every day of the year.
To offset that with solar you’d have to overprovision solar so that you can both supply daytime power while at the same time charging a massively huge battery so that it can make the night.

Think of it this way. You want to replace a 600MW coal power station. Ok. That means that at the present time you’re drawing a continuous 600MW for simplicity sake. In a 24 hour period you’re looking at 14,400 MWh or 14,400,000 kWh.

So let’s say 10 hours of useful daylight and 14 hours of nighttime/dusk/dawn.

So in the 10 hours of daytime you have to full up the battery for the 14 hours of night.

Your demand: 600MW
Energy needed:
10 hours (day): 600MW * 10h = 6000MWh
14 hours (night): 600MW * 14h = 8400MWh

Based on optimal PV plant generation in SA (1800kWh/kW/a) you’re looking at a necessary PV farm that’s 2,880 MW in size. This way you can both power the daytime load and charge thre battery for when there’s no sun.

Then the battery 8,400 MWh = 8,400,000 kWh.

In summary
Solar farm: 2,880 MW (2,880,000 kW) * R10,000/kW = R28,800,000,000
Battery: 8,400 MWh (8,400,000 kWh) * $500/kWh (R7,500/kWh) = 63,000,000,000
Total: 71,000,000,000

This rough calculation is also for a perfectly sunny day for one (just one) coal power plant replacement . What happens if the next day is a little rainy or overcast. Then your battery will be empty at some point during the night. Then what? Are you going to fire up the coal power station? What if it’s like two or three days of overcast weather?

Something like Medupi may cost many times more but it generates power at all times of the day no matter the weather. Even with nonsense ‘wet coal’ the output is still high.

Solar and storage is nice and it can provide many grid services like a replacement for spinning reserve or frequency control but it will not be a replacement for power station no matter how much we all hope and pray.
You may not realise how much energy is necessary to run a country.

 

[hj2k_x]

I’m afraid you are misinformed. The amount of energy that needs to be stored to power anything like a town for any amount of reasonable time is insanely huge. Keep in mind that any old power station in Mpumalanga goes through about 600 tons of coal per hour every hour of the day and every day of the year.
To offset that with solar you’d have to overprovision solar so that you can both supply daytime power while at the same time charging a massively huge battery so that it can make the night.

Think of it this way. You want to replace a 600MW coal power station. Ok. That means that at the present time you’re drawing a continuous 600MW for simplicity sake. In a 24 hour period you’re looking at 14,400 MWh or 14,400,000 kWh.

So let’s say 10 hours of useful daylight and 14 hours of nighttime/dusk/dawn.

So in the 10 hours of daytime you have to full up the battery for the 14 hours of night.

Your demand: 600MW
Energy needed:
10 hours (day): 600MW * 10h = 6000MWh
14 hours (night): 600MW * 14h = 8400MWh

Based on optimal PV plant generation in SA (1800kWh/kW/a) you’re looking at a necessary PV farm that’s 2,880 MW in size. This way you can both power the daytime load and charge thre battery for when there’s no sun.

Then the battery 8,400 MWh = 8,400,000 kWh.

In summary
Solar farm: 2,880 MW (2,880,000 kW) * R10,000/kW = R28,800,000,000
Battery: 8,400 MWh (8,400,000 kWh) * $500/kWh (R7,500/kWh) = 63,000,000,000
Total: 71,000,000,000

This rough calculation is also for a perfectly sunny day for one (just one) coal power plant replacement . What happens if the next day is a little rainy or overcast. Then your battery will be empty at some point during the night. Then what? Are you going to fire up the coal power station? What if it’s like two or three days of overcast weather?

Something like Medupi may cost many times more but it generates power at all times of the day no matter the weather. Even with nonsense ‘wet coal’ the output is still high.

Solar and storage is nice and it can provide many grid services like a replacement for spinning reserve or frequency control but it will not be a replacement for power station no matter how much we all hope and pray.
You may not realise how much energy is necessary to run a country.

https://www.sciencealert.com/world-...-internationally-from-australia-under-the-sea how much is 10 gigawatt? Probably quite a lot?

 

[richjdavies]

I’m afraid you are misinformed. The amount of energy that needs to be stored to power anything like a town for any amount of reasonable time is insanely huge. Keep in mind that any old power station in Mpumalanga goes through about 600 tons of coal per hour every hour of the day and every day of the year.
To offset that with solar you’d have to overprovision solar so that you can both supply daytime power while at the same time charging a massively huge battery so that it can make the night.

Think of it this way. You want to replace a 600MW coal power station. Ok. That means that at the present time you’re drawing a continuous 600MW for simplicity sake. In a 24 hour period you’re looking at 14,400 MWh or 14,400,000 kWh.

So let’s say 10 hours of useful daylight and 14 hours of nighttime/dusk/dawn.

So in the 10 hours of daytime you have to full up the battery for the 14 hours of night.

Your demand: 600MW
Energy needed:
10 hours (day): 600MW * 10h = 6000MWh
14 hours (night): 600MW * 14h = 8400MWh

Based on optimal PV plant generation in SA (1800kWh/kW/a) you’re looking at a necessary PV farm that’s 2,880 MW in size. This way you can both power the daytime load and charge thre battery for when there’s no sun.

Then the battery 8,400 MWh = 8,400,000 kWh.

In summary
Solar farm: 2,880 MW (2,880,000 kW) * R10,000/kW = R28,800,000,000
Battery: 8,400 MWh (8,400,000 kWh) * $500/kWh (R7,500/kWh) = 63,000,000,000
Total: 71,000,000,000

This rough calculation is also for a perfectly sunny day for one (just one) coal power plant replacement . What happens if the next day is a little rainy or overcast. Then your battery will be empty at some point during the night. Then what? Are you going to fire up the coal power station? What if it’s like two or three days of overcast weather?

Something like Medupi may cost many times more but it generates power at all times of the day no matter the weather. Even with nonsense ‘wet coal’ the output is still high.

Solar and storage is nice and it can provide many grid services like a replacement for spinning reserve or frequency control but it will not be a replacement for power station no matter how much we all hope and pray.
You may not realise how much energy is necessary to run a country.

So many fallacies here...

We have a thing that can produce 600MW say and it's so stupid it has to burn it constantly 24 hours a day... The demand is NOT there to use that power but for some reason you think it's capacity is important rather than the demand. Having 24/7 the same production is a problem too... Just one we have already engineered out of.

Next just because you are used to 600MW on the name.plate, doesn't mean you should look down on 600MW of solar as inferior. It is different.
Compare a XX kWh plant with a XX kWh solar plant.
Just make it bigger and it's fine!?

The cost comparison is not on MW basis it's a kWh basis.

Btw you actually get only about 5/6 hours / day of effective output from solar... So the numbers are actually much worse than you think

 

[Mike Hoxbig]

I’m afraid you are misinformed. The amount of energy that needs to be stored to power anything like a town for any amount of reasonable time is insanely huge. Keep in mind that any old power station in Mpumalanga goes through about 600 tons of coal per hour every hour of the day and every day of the year.
To offset that with solar you’d have to overprovision solar so that you can both supply daytime power while at the same time charging a massively huge battery so that it can make the night.

Think of it this way. You want to replace a 600MW coal power station. Ok. That means that at the present time you’re drawing a continuous 600MW for simplicity sake. In a 24 hour period you’re looking at 14,400 MWh or 14,400,000 kWh.

So let’s say 10 hours of useful daylight and 14 hours of nighttime/dusk/dawn.

So in the 10 hours of daytime you have to full up the battery for the 14 hours of night.

Your demand: 600MW
Energy needed:
10 hours (day): 600MW * 10h = 6000MWh
14 hours (night): 600MW * 14h = 8400MWh

Based on optimal PV plant generation in SA (1800kWh/kW/a) you’re looking at a necessary PV farm that’s 2,880 MW in size. This way you can both power the daytime load and charge thre battery for when there’s no sun.

Then the battery 8,400 MWh = 8,400,000 kWh.

In summary
Solar farm: 2,880 MW (2,880,000 kW) * R10,000/kW = R28,800,000,000
Battery: 8,400 MWh (8,400,000 kWh) * $500/kWh (R7,500/kWh) = 63,000,000,000
Total: 71,000,000,000

This rough calculation is also for a perfectly sunny day for one (just one) coal power plant replacement . What happens if the next day is a little rainy or overcast. Then your battery will be empty at some point during the night. Then what? Are you going to fire up the coal power station? What if it’s like two or three days of overcast weather?

Something like Medupi may cost many times more but it generates power at all times of the day no matter the weather. Even with nonsense ‘wet coal’ the output is still high.

Solar and storage is nice and it can provide many grid services like a replacement for spinning reserve or frequency control but it will not be a replacement for power station no matter how much we all hope and pray.
You may not realise how much energy is necessary to run a country.

This is why most countries don't dump all their eggs into one basket. It's supplemented by wind, water and other renewables. We have dams, put them to use. We have windy cities, put them to use. We have vast pieces of sunny, arid land, put them to use...

 

[Iwojima]

Waits for the day when no one buys oil from Saudi Arabia

Not in any of our lifetimes I'm afraid.

Ineffective? How is it ineffective?

Ineffective in replacing dispatchable base loads without a large scale, reliable and proven storage solution.

When the payback period for residential solar and storage is about 7 years, I suspect the large scale plants will also do better.

And frankly the "base load" generator argument is a bit of a strawman. The grid always has to match supply with demand - baseload just meant supply was fixed whilst demand was variable. Now both are variable - we can engineer our way out of it. From storage to time-of-day tariffs to shift demand. I think the future is bright!

The point of the baseload argument is the dispatchability of the supply and the variability of the generation based on factors out of our control, e.g. weather. You cannot move away from this is even if you solve the storage conundrum.

Shifting demand to when? Doesn't change the fact that you will always have variable wind and solar output in a given day and most renewables do not produce nearly same output in the evening.

This is why most countries don't dump all their eggs into one basket. It's supplemented by wind, water and other renewables. We have dams, it them to use. We have windy cities, put them to use. We have vast pieces of sunny, arid land, put them to use...

Nor should we. Renewables can supplement, not replace. Solar is probably the most viable in this regard as wind plants are environmentally unfeasible at a large scale in the places where we have the most wind. As for pumped storage/dams...we are not a water rich country nor do we have many potential sites where significant generation by hydro is possible.

 

[SoldierMan]

As it said in the article, battery storage,

For a whole country?
Talk about expensive.....

 

[Johand]

Tell the corrupt cANCer that.

Well what is going to happen is what always happens, the gap will be filled by the private sector. I think everybody will be surprised in 5 years time on how much energy is produced by the private sector vs Eskom. Raising the self generation limit to 100MW is a game changer.

 

[mypetcow]

The demand is NOT there to use that power but for some reason you think it's capacity is important rather than the demand. Having 24/7 the same production is a problem too... Just one we have already engineered out of.

Don’t know about you but I think that a continuous demand of at least 25,000MW+ is larger than 600MW. So either Eskom is lying on their website and their data is purely fabricated or your statement that ‘the demand for 600MW continuous is NOT there’ isn’t entirely correct….

 

[Iwojima]

For a whole country?
Talk about expensive.....

...and unproven at anywhere close to that scale.

Well what is going to happen is what always happens, the gap will be filled by the private sector. I think everybody will be surprised in 5 years time on how much energy is produced by the private sector vs Eskom. Raising the self generation limit to 100MW is a game changer.

I mean this is clearly even part of the plan to dismantle Eskom into Generation, Transmission and Distribution entities. Personally I'd agree that the future looks rosy for private generation.

 

[Johnatan56]

Don’t know about you but I think that a continuous demand of at least 25,000MW+ is larger than 600MW. So either Eskom is lying on their website and their data is purely fabricated or your statement that ‘the demand for 600MW continuous is NOT there’ isn’t entirely correct….

As you can see by the name of the graph, that's averaged hourly, not what it is at multiple shorter points in time. A better screenshot of the graph right now:

Part of the shift to demand side is handling reacting within seconds (or actually ms), using e.g. batteries or other storage tech to smooth that out. In the above you can see that the contracted is way above the actual forecast.

With coal for example, in order to ramp up supply takes hours, you can't decide to burn a bit less coal for the next few minutes and then ramp it up again.

 

[Kawak]

I’m afraid you are misinformed. The amount of energy that needs to be stored to power anything like a town for any amount of reasonable time is insanely huge. Keep in mind that any old power station in Mpumalanga goes through about 600 tons of coal per hour every hour of the day and every day of the year.
To offset that with solar you’d have to overprovision solar so that you can both supply daytime power while at the same time charging a massively huge battery so that it can make the night.

Think of it this way. You want to replace a 600MW coal power station. Ok. That means that at the present time you’re drawing a continuous 600MW for simplicity sake. In a 24 hour period you’re looking at 14,400 MWh or 14,400,000 kWh.

So let’s say 10 hours of useful daylight and 14 hours of nighttime/dusk/dawn.

So in the 10 hours of daytime you have to full up the battery for the 14 hours of night.

Your demand: 600MW
Energy needed:
10 hours (day): 600MW * 10h = 6000MWh
14 hours (night): 600MW * 14h = 8400MWh

Based on optimal PV plant generation in SA (1800kWh/kW/a) you’re looking at a necessary PV farm that’s 2,880 MW in size. This way you can both power the daytime load and charge thre battery for when there’s no sun.

Then the battery 8,400 MWh = 8,400,000 kWh.

In summary
Solar farm: 2,880 MW (2,880,000 kW) * R10,000/kW = R28,800,000,000
Battery: 8,400 MWh (8,400,000 kWh) * $500/kWh (R7,500/kWh) = 63,000,000,000
Total: 71,000,000,000

This rough calculation is also for a perfectly sunny day for one (just one) coal power plant replacement . What happens if the next day is a little rainy or overcast. Then your battery will be empty at some point during the night. Then what? Are you going to fire up the coal power station? What if it’s like two or three days of overcast weather?

Something like Medupi may cost many times more but it generates power at all times of the day no matter the weather. Even with nonsense ‘wet coal’ the output is still high.

Solar and storage is nice and it can provide many grid services like a replacement for spinning reserve or frequency control but it will not be a replacement for power station no matter how much we all hope and pray.
You may not realise how much energy is necessary to run a country.

When the problem of pollution from the burning of generation fuel is eliminated, all roof tops become viable places for generation, my, rather energy efficient home, is able to generate 133% of required energy, using 60sqm of roof space, that includes paths for me to clean the panels. Another 10sqm is used to generate hot water, this totals less than half of my sun facing roof.

As I am now planning for an off grid future, I am busy building a battery cabinet able to house storage for 2.5days of energy use, size required is 1.5m x 1.5m x 0.75m, this includes space for air flow, wiring and substantial excess for possible needs.

We have more than enough space for green energy, what we lack is imagination and the will to change. Luckily, eskom is forcing us to be imaginative and our useless local councils has definitely steeled my resolve to be independent from them.

 

[Utterly Confused]

When the problem of pollution from the burning of generation fuel is eliminated, all roof tops become viable places for generation, my, rather energy efficient home, is able to generate 133% of required energy, using 60sqm of roof space, that includes paths for me to clean the panels. Another 10sqm is used to generate hot water, this totals less than half of my sun facing roof.

As I am now planning for an off grid future, I am busy building a battery cabinet able to house storage for 2.5days of energy use, size required is 1.5m x 1.5m x 0.75m, this includes space for air flow, wiring and substantial excess for possible needs.

We have more than enough space for green energy, what we lack is imagination and the will to change. Luckily, eskom is forcing us to be imaginative and our useless local councils has definitely steeled my resolve to be independent from them.

I wouldn’t be surprised if these wankers bring a self-generation tax into play.

 

[RonSwanson]

I wouldn’t be surprised if these wankers bring a self-generation tax into play.

No self-respecting communist government would ever allow something like that to be successful. It goes against every single Marxist principle, that of being a filthy, lazy, lecherous leech that sucks the lifeblood out of every single thing that is remotely successful, regardless of gender, skin colour or faith, all have to pay homage to the stinking indolent mass of rotting flesh that Karl Marx was, and still is today.
Marx was deceitful and far too lazy to work, never had a proper job, and leeched off the women in his life. He was so lazy that he never even had a proper bath. What an utter waste of human flesh. Yet today, he inspires all of our leading politicians, and it shows.

 

[Johnatan56]

I wouldn’t be surprised if these wankers bring a self-generation tax into play.

I doubt that will happen, instead it will just be a rates increase, and probably a tax increase on existing stuff, maybe an added one making solar/battery systems luxury.

 

[dj_jyno]

When the problem of pollution from the burning of generation fuel is eliminated, all roof tops become viable places for generation, my, rather energy efficient home, is able to generate 133% of required energy, using 60sqm of roof space, that includes paths for me to clean the panels. Another 10sqm is used to generate hot water, this totals less than half of my sun facing roof.

As I am now planning for an off grid future, I am busy building a battery cabinet able to house storage for 2.5days of energy use, size required is 1.5m x 1.5m x 0.75m, this includes space for air flow, wiring and substantial excess for possible needs.

We have more than enough space for green energy, what we lack is imagination and the will to change. Luckily, eskom is forcing us to be imaginative and our useless local councils has definitely steeled my resolve to be independent from them.

That's what I've been thinking as well. Solar is perfect for decentralising the energy supply. We're still too stuck in the mindset of needing a massive power plant to generate electricity.

All that dead space on industrial roofs could very easily be covered in solar panels. I've seen some ideal north-facing roofs with the perfect pitch, and one large factory's roof alone can host a 1.5 MW array.

 

[richjdavies]

Don’t know about you but I think that a continuous demand of at least 25,000MW+ is larger than 600MW. So either Eskom is lying on their website and their data is purely fabricated or your statement that ‘the demand for 600MW continuous is NOT there’ isn’t entirely correct….

Umm... Missed the context here. The OP was saying one coal plant is 600MW... We were not talking about the whole country.

 

[mypetcow]

Umm... Missed the context here. The OP was saying one coal plant is 600MW... We were not talking about the whole country.

The 600MW is part of the 25,000MW+

The continuous demand is greater than 25,000MW therefore it is always greater than 600MW…so there will always be demand for the 600MW continuous…I’m not sure what you think I missed

 

[richjdavies]

The 600MW is part of the 25,000MW+

The continuous demand is greater than 25,000MW therefore it is always greater than 600MW…so there will always be demand for the 600MW continuous…I’m not sure what you think I missed

Demand = supply...

Let that sink in for a moment.

So what do you think those 20,000MW of coal is doing at 3am?... Baseload isn't big or clever you are just used to it.