There's no reason wind backup generation (in this simple 3 bus model) needs to be a simple cycle CT.
Combined cycles can and do ramp up and down, a lot, and can ramp quickly to balance the variation in wind output.
In your simple example of 1 GW load being served, there's no plausible reason that it can't be served by a 35% capacity factor wind farm and a CCGT, rather than simple cycle.
They certainly don't. Many CCGTs ramp frequently and enter peak firing or duct firing mode on a regular basis (e.g. 5 days a week). This causes some O&M increases and loss in efficiency, but not enough to switch to a much less efficient simple cycle turbine.
Ireland is also a small (basically) islanded system. Large systems have the advantages of wide geographic spread to limit the wind volatility, and a large resource pool. This whole "backup" power premise doesn't work for large ISO regions anyway, where they have to procure backup power at all times, unrelated to wind.
If we're talking cost, sure, there's an argument against wind/solar, but the CO2 argument doesn't work.
First off thank you. First docs I've seen from NREL discussing this.
I've scanned them. Biggest take-away is they need to perform this research again today. They are looking at the system 15 years ago and a lot of the reserve came from coal. I'll agree that replacing coal, even if for 1/3 of the time, is a win. Because it was 15 years ago there's no consideration of SCGT vs CCGT. At least not that I can find.
I'll put it on my list to write an upcoming blog on this in the near future.
The system mix still contains coal, and coal is more expensive than a new and clean CCGT so it's displaced first.
ISO systems procure "backup" power through a mix of ancillary services and capacity procurement. There are some characteristics that only some resource types can fill, e.g. quick-start SCGT, but those would be procured *anyway* independent of having wind on the system.
It's likely wind has somewhat increased the need for fast-regulation on the system (mainly filled by batteries) but again, that's an overall system cost issue rather than emissions specifically.
Texas has bet big on wind and solar and people like Noah Smith @noahpinion are touting their wholesale production costs of $.003/KWh (clearly ignoring the backup). But does TX have a backup strategy other than brownouts, or do they just not care about total CO2 emissions?
2. I'm not certain how to do the math, but one substantial variance is wind power is not a single spot calculation. When the wind is blowing in Wyoming (most of the time, in my experience) your calculations may be relevant to those turbines. But when the wind stops in Wyoming, there is a pretty high chance it is blowing in Colorado, New Mexico, and Texas. The overall calculation of grid-wide capacity ought to be the guide for comparison.
Uh, wind blowing in Texas has no impact elsewhere as the ERCOT is not connected to the West or East grid. And the grid does not have the capacity to routinely move large amounts of power long distances. Those HVAC & HVDC lines are all fully utilized.
In fact there's a large problem that companies want to build wind and solar farms and can't because running transmission lines to them is a 7 year approval and permitting process.
A capacity factor of 41% does not mean that the turbine is producing energy at 100% of capacity 41% of the time and not producing any energy 59% of the time.
It will be producing some amount of energy most of the time.
For your 1 GW of demand hypothetical, you assemble a wind farm with 2 or 3 GW capacity. Sometimes it will be overproducing and curtailed (or feed batteries). Sometimes it will be producing roughly the right amount of energy (which can be rounded out with batteries). And sometimes it will need to be backed up by SCGT generation.
I understand capacity factor. It's very useful because instead if you run the math with say the turbine running at 50% for twice the time - the math comes out the same.
Can you provide info on a wind farm that is using batteries? I have not been able to find any. Best as I can tell they're either feeding into the grid or, very rarely, shut off when the grid has excess energy.
I don't see where you calculated or explained how wind turbines produce CO2.
Wind turbines use fuel energy (CO2) to be manufactured initially but after that just rotate ,alther maintenance costs produce CO2 as in every aspect of life.
There's no reason wind backup generation (in this simple 3 bus model) needs to be a simple cycle CT.
Combined cycles can and do ramp up and down, a lot, and can ramp quickly to balance the variation in wind output.
In your simple example of 1 GW load being served, there's no plausible reason that it can't be served by a 35% capacity factor wind farm and a CCGT, rather than simple cycle.
Ireland tried using CCGTs for backup. It was less efficient and emitted more CO2 than using SCGTs. CCGTs perform poorly being ramped up/down.
They certainly don't. Many CCGTs ramp frequently and enter peak firing or duct firing mode on a regular basis (e.g. 5 days a week). This causes some O&M increases and loss in efficiency, but not enough to switch to a much less efficient simple cycle turbine.
Ireland is also a small (basically) islanded system. Large systems have the advantages of wide geographic spread to limit the wind volatility, and a large resource pool. This whole "backup" power premise doesn't work for large ISO regions anyway, where they have to procure backup power at all times, unrelated to wind.
If we're talking cost, sure, there's an argument against wind/solar, but the CO2 argument doesn't work.
In that case find me a single study that backs up your statement. I've yet to find a single study from NREL that even has the word "backup" in it.
https://www.nrel.gov/docs/fy15osti/63045.pdf
I wrote a post diving into the document and the studies it references. Tentatively going up Thursday.
First off thank you. First docs I've seen from NREL discussing this.
I've scanned them. Biggest take-away is they need to perform this research again today. They are looking at the system 15 years ago and a lot of the reserve came from coal. I'll agree that replacing coal, even if for 1/3 of the time, is a win. Because it was 15 years ago there's no consideration of SCGT vs CCGT. At least not that I can find.
I'll put it on my list to write an upcoming blog on this in the near future.
The system mix still contains coal, and coal is more expensive than a new and clean CCGT so it's displaced first.
ISO systems procure "backup" power through a mix of ancillary services and capacity procurement. There are some characteristics that only some resource types can fill, e.g. quick-start SCGT, but those would be procured *anyway* independent of having wind on the system.
It's likely wind has somewhat increased the need for fast-regulation on the system (mainly filled by batteries) but again, that's an overall system cost issue rather than emissions specifically.
Texas has bet big on wind and solar and people like Noah Smith @noahpinion are touting their wholesale production costs of $.003/KWh (clearly ignoring the backup). But does TX have a backup strategy other than brownouts, or do they just not care about total CO2 emissions?
I believe they have sufficient backup to handle no solar/wind.
Two thoughts:
1. NREL has a sophisticated calculator for wind: "Before You Install Wind Energy Technology, Check Out This Database" https://www.nrel.gov/news/program/2024/before-you-install-wind-energy-technology-check-out-this-database.html
2. I'm not certain how to do the math, but one substantial variance is wind power is not a single spot calculation. When the wind is blowing in Wyoming (most of the time, in my experience) your calculations may be relevant to those turbines. But when the wind stops in Wyoming, there is a pretty high chance it is blowing in Colorado, New Mexico, and Texas. The overall calculation of grid-wide capacity ought to be the guide for comparison.
Uh, wind blowing in Texas has no impact elsewhere as the ERCOT is not connected to the West or East grid. And the grid does not have the capacity to routinely move large amounts of power long distances. Those HVAC & HVDC lines are all fully utilized.
In fact there's a large problem that companies want to build wind and solar farms and can't because running transmission lines to them is a 7 year approval and permitting process.
Is that because of roadblocks like NEPA or is it due to a long queue built up over the years, both, or something else?
I'm guessing each proposed transmission line has its own set of problems. But NEPA tends to be a big part of it for most of them.
You are misinterpreting capacity factor.
A capacity factor of 41% does not mean that the turbine is producing energy at 100% of capacity 41% of the time and not producing any energy 59% of the time.
It will be producing some amount of energy most of the time.
For your 1 GW of demand hypothetical, you assemble a wind farm with 2 or 3 GW capacity. Sometimes it will be overproducing and curtailed (or feed batteries). Sometimes it will be producing roughly the right amount of energy (which can be rounded out with batteries). And sometimes it will need to be backed up by SCGT generation.
I understand capacity factor. It's very useful because instead if you run the math with say the turbine running at 50% for twice the time - the math comes out the same.
Can you provide info on a wind farm that is using batteries? I have not been able to find any. Best as I can tell they're either feeding into the grid or, very rarely, shut off when the grid has excess energy.
Are you sure your thinking in not conservative nationalistic
No and WTF does that have to do with energy policy?
I don't see where you calculated or explained how wind turbines produce CO2.
Wind turbines use fuel energy (CO2) to be manufactured initially but after that just rotate ,alther maintenance costs produce CO2 as in every aspect of life.
They require a SCGT as the backup generation when the wind is not blowing. That produces CO2.