UK 18 month study shows wind requires less backup than conventional generation

[kristopher]

EVIDENCE SHOWS WIND FARMS DON'T NEED FOSSIL FUEL BACK-UP

It has become an article of popular faith that building wind farms also involves constructing fossil-fuelled power stations for back‑up when the weather is calm. As a result, some opponents go on to say, wind turbines do little or nothing to cut carbon dioxide emissions.

Now the National Grid has studied what actually happens in practice, with explosive, if surprising, results.

Between April 2011 and September 2012 – its head of energy strategy, Richard Smith, told the Hay Festival – wind produced some 23,700 gigawatt hours (GWh) of power. Only 22GWh of power from fossil fuels was needed to fill the gaps when the wind didn’t blow. That’s less than a thousandth of the turbines’ output – and, as it happens, less than a tenth of what was needed to back up conventional power stations.

It proved to be much the same with emissions. Wind saved nearly 11 million tonnes of carbon dioxide over that 18 months; standby burning of fossil fuels only reduced this by 8,800 tonnes, or 0.081 per cent.
Not surprisingly, given these figures, no new fossil‑fuel power station has been built to provide back‑up for wind farms, and none is in prospect.

http://www.telegraph.co.uk/earth/wildlife/10091645/The-badger-cull-is-no-black-and-white-issue.html

I'm looking for more information on this study to clarify the results. - k

[madokie]

1. Any electricity we get from wind has to be a win for everyone

How can it not?

[Fumesucker]

3. You are obviously not in the oil bidness n/t

[quadrature]

2. the wind people can force you to buy electricity from them

and when they(the wind merchants) don't
feel like
selling you some electricity,
they will let you buy from anyone else.
What wonderful people!

[jpak]

4. K&R and Bookmarked

[FBaggins]

5. You really need more information to know that this is bunk?

This wasn't a measure of how much power was generated "when the weather is calm"... the fossil plants that are running when the wind isn't blowing weren't scored as "backing up" the wind plants. It was instead a measure of how much energy was provided by the short-term operating reserve to cover wind gaps that varied from predictions.

So if the weather report for tomorrow says that there won't be any wind... the fact that some other plant burns extra fuel to fill the gap would not be scored as something "needed to back up wind power"... even though that's exactly what it's doing. If it's forecast to blow hard enough to generate 10 mWh at a particular facility and the net for the day is 9.5 mWh instead... only the .5 mWh would be "scored" for this measure.

In short - it isn't telling you how much generation was needed to fill the gap between wind and no-wind. It was to fill the gap between projected wind and actual wind. Simlarly, the carbon intensity data (the actual purpose of the study) was just attempting to measure the inefficiency involved in running fossil plants less efficiently when they're balancing wind generation. It wasn't a measure of carbon emissions from plants that are running when the wind isn't blowing (unless it was predicted to blow and didn't). I expect that this could vary considerably from one scenario to the next... but it should always be pretty small compared to total wind generation. But it tells us nothing about how much backup generation is needed for high penetrations of renewables. The study you used to spam does a better job (though still inadequate) of estimating fossil backup to hit a particular target.

There's really nothing new here. So long as variable renewables make up a small portion of total generation, the existing flexibility of most grids can handle the variability without much trouble. It also confirms what we have long said... the variability does not mean the inability to plan effectively. Lastly... it puts to rest nonsensical claims that just the required spinning reserves produce enough carbon to offset wind generation.

Here's the original source:

http://www.scottish.parliament.uk/S4_EconomyEnergyandTourismCommittee/NATIONAL_GRID.pdf

Oh... and if you're going to link to a page on badgers... don't you think it would be wise to note "couldn't find a direct link... it's the third topic down" or "I've included the entire content here" ?

[kristopher]

6. Another one of your creative interpretations?

The word is "citation" - USE THEM.

You have been producing an escalating string of 'creative' posts lately, all composed in the same fashion. Unsupported claims about meaning or content of given documents that turns out to be highly misrepresentative of the actual source information.

When expressing Your Opinion, it is fine to write in the style of your post, however when you are claiming as fact your accounting of the content of a report include a citation. You've demonstrated too many times that you are entirely capable of documenting the genesis of your ideas properly for to allow for a charitable interpretation of your refusal to cite or write clearly or concisely. It is obvious you are employing a generalized style intended quite deliberately to allow you room to forget all ethical standards for adhering accurately to your reporting.

Where, exactly, does it contain this information?
"It was instead a measure of how much energy was provided by the short-term operating reserve to cover wind gaps that varied from predictions. "


Where, exactly, does it contain support for this example?
"So if the weather report for tomorrow says that there won't be any wind... the fact that some other plant burns extra fuel to fill the gap would not be scored as something "needed to back up wind power"... even though that's exactly what it's doing."

What is the specific language that supports this statement?
"it isn't telling you how much generation was needed to fill the gap between wind and no-wind. It was to fill the gap between projected wind and actual wind"


Let's start with those and see where we end up.

[FBaggins]

7. You do seem to have trouble with mathematical examples, don't you?

The word is "citation" - USE THEM.

You said you were looking for more information and I gave you a direct link to the source. You might try READING IT. It's neither my job to do the reading for you... nor my inclination based on your prior history of demanding such efforts and then running from the conversation when you realize how wrong you were (only to bring it back up months later as if the discussion never happened).

You have been producing an escalating string of 'creative' posts lately

Nope. Just relevant examples fleshing out the cases under discussion that you instead took to be claims of precision without foundation ("claiming as fact" when no such claim was made). This misreading on your part goes back at least a couple years to your inability to tell the difference between a curve and the first and second derivative involved.

Let's start with those and see where we end up.

Why don't you instead start by reading what you asked for and see whether it supports the nonsensical claims of the OP that anyone with a reasonable grasp of mathematics would know couldn't possibly have been accurate?

If you need some part of it explained... then I'll be happy to help.

[kristopher]

8. I'm not playing your game of evasion Baggins.

Here is a sample of your method of disruption at work.
"IKEA starts selling solar panels in Britain"
http://www.democraticunderground.com/112754810

By refusing to cite you feel you can craft your wild interpretations and then dance around with more tripe when confronted. All of that nonsense is avoided when you provide clear sourcing for the conclusions you are drawing from a specific source; the temptation for fabricating falsehoods is removed, errors are readily identified and actual discussion can take place.

Document your claims with specificity. You have trashed any claim to the trust that enables dialog to proceed otherwise.

ETA: Thank you for finding information about the source. I did read it and it supports the claims made in the OP. Your assertions on the topic are nothing more than bullpuckey designed to muddy the waters.

[FBaggins]

9. A simple "yes" wold have sufficed.

Your attempt to divert attention from your latest error is transparent.

All of that nonsense is avoided when you provide clear sourcing for the conclusions

I can refer you to a math textbook for sourcing... but I can't make you read it.

One wonders though... how you see a difference (apart from more realistic examples) between that and your neverending attempts to convert the manufacturing capacity of a plant that produces part of a system... into an equivelency of a number of reactors?

Document your claims with specificity.

I did. I gave you the study you asked for and explained the OP's error in reading it. The author (and you in defending him) gave less specificity than that. Making unsubstantiated claims up out of whole cloth that were clearly impossible.

ETA: Thank you for finding information about the source. I did read it and it supports the claims made in the OP



Then you're just plain nuts or inable to convert a word problem into a mathematical statement and analyze it. It wouldn't be the first time... but it's certainly a clear one.

"Only 22GWh of power from fossil fuels was needed to fill the gaps when the wind didn’t blow." is not at all the same thing as "due to wind output being lower than forecast"

But it is exactly the same as " a measure of how much energy was provided by the short-term operating reserve to cover wind gaps that varied from predictions" just as "that is estimated to be due to real time wind output being less than forecast" is the same thing as "the gap between projected wind and actual wind"

Your inability to to accept your error even when it's this crystal clear is also telling.

[kristopher]

10. I'm not playing your game of evasion Baggins

Here is a sample of your method of disruption at work.
"IKEA starts selling solar panels in Britain"
http://www.democraticunderground.com/112754810

By refusing to cite you feel you can craft your wild interpretations and then dance around with more tripe when confronted. All of that nonsense is avoided when you provide clear sourcing for the conclusions you are drawing from a specific source; the temptation for fabricating falsehoods is removed, errors are readily identified and actual discussion can take place.

Document your claims with specificity. You have trashed any claim to the trust that enables dialog to proceed otherwise.

[FBaggins]

11. Right... you've got your own games.

You have trashed any claim to the trust that enables dialog to proceed otherwise.

You keep telling yourself that.

Document your claims with specificity.

I just did... and you desperately hope to change the subject.

[kristopher]

12. No you didn't.

Your claims regarding the lack of accuracy in the OP are not true. If you truly believe they are false, it means you do not understand what you are reading. To determine What, Precisely, you do not understand requires you to explain what specific information renders those claims false.

[FBaggins]

13. I gave you the specific quotes.

How much simpler can I make it?

The OP claims (without any possibility of spin) that this is the amount of generation needed "to fill the gaps when the wind didn’t blow". The report (again clearly and without possibilty of spin) says nothing of the sort. Instead, it's measuring only the backup generation needed to cover the delta between reality and predictions. This is because some people (seen here frequently) attempt to claim that wind power doesn't save as much carbon as the generation implies... because some of that carbon emission is offset by plants having to ramp up and down unexpectedly. All they did was quantify that offset.

Even more explicitly, he translated this into "wind farms don't need fossil fuel backup"... which is in no way even addressed in the study. The study knew that wind farms in the current grid require other generation (though it needent be fossil) in order to meet demand. They were only trying to measure the carbon impact of inability to predict exactly what the variability would be.

I point you yet again to your own spammed source from late last year. Even with many MANY times the penetration of wind as the UK has, they still had to have way more than .08% fossil backup to reliably meet demand.

[kristopher]

15. Wow, how much more could you screw it up?

The OP claims (without any possibility of spin) that this is the amount of generation needed "to fill the gaps when the wind didn’t blow".

That is, indeed, ambiguous. However it isn't false as you claimed. You chose to ignore the valid reading in your first post. Good of you to backtrack and admit your presentation on this point was a red herring.

Even more explicitly, he translated this into "wind farms don't need fossil fuel backup"... which is in no way even addressed in the study.

No, it isn't addressed in the study; but it is a conclusion that is an inevitable implication of the data. As the Kempton study demonstrated, more wind DOES NOT require fossil fuel backup. The more wind more you build the more you reduce dependency on fossil fuels - period. You reduce not only the amount required to directly serve user needs but also the follow-on requirement for reserves.

Additionally, just because Kempton elected to use a least cost from a limited set of generating sources approach to solving the problem doesn't mean it is "0.08%" fossil fuels is REQUIRED. Functionally that could be filled by landfill gas or any other dispatchable renewable fuel.

[kristopher]

14. I don't blame you for hiding

This wasn't a measure of how much power was generated "when the weather is calm"... the fossil plants that are running when the wind isn't blowing weren't scored as "backing up" the wind plants.

No one said it was.

It was instead a measure of how much energy was provided by the short-term operating reserve to cover wind gaps that varied from predictions.

False by omission. It also measured:

1. Direct carbon emissions reduction estimated through the total volume of energy generated by wind farms.
2. Volume of gas used by Generators compared with the amount of electricity generated over time to determine whether the intermittent nature of wind generators’ output has affected the carbon intensity of the generation fleet.
3. Calculation of indirect carbon emissions arising from energy generated by Short Term Operating Reserve that is estimated to be due to real time wind output being less than forecast.

The goal of which was:

"To quantify wind generation impacts (on) the carbon intensity of the remaining generation fleet"

You continue:

So if the weather report for tomorrow says that there won't be any wind... the fact that some other plant burns extra fuel to fill the gap would not be scored as something "needed to back up wind power"... even though that's exactly what it's doing. If it's forecast to blow hard enough to generate 10 mWh at a particular facility and the net for the day is 9.5 mWh instead... only the .5 mWh would be "scored" for this measure.

No, that is only one aspect of what is happening. Here is what they actually write:

Electricity Suppliers purchase electricity that they forecast their customers will use from Generators. Generators notify their consequent expected output profile to the NETSO and self-dispatch their plant to meet this profile. If necessary, the NETSO accepts bids and offers1 from Generators to alter their output to ensure that actual electricity demand is met in real time. In addition the NETSO ensures that there is an appropriate amount of generating capacity (reserve) above and below forecast demand. This capacity ensures that the system remains secure, within a defined set of criteria, if the demand turns out to be higher or lower than forecast, if there are generation losses, if there are demand losses
e.g.: pumping demand) or if the output from the wind farm2 fleet turns out to be higher or lower than forecast.
A proportion of reserve is either committed or stood down ahead of real time (Contingency Reserve); a proportion of reserve is held on unsynchronised plant

A) if the demand turns out to be higher or lower than forecast,
B) if there are generation losses,
C) if there are demand losses e.g.: pumping demand) or
D) if the output from the wind farm fleet turns out to be higher or lower than forecast.

All of those are relevant considerations.

"In short - it isn't telling you how much generation was needed to fill the gap between wind and no-wind."

No one claimed it was. The actual claim was that the variation in grid conditions causes a requirement for back up during operations. The question examined (in response to claims by the nuclear and fossil fuel industry) was "Does the variability of wind reduce its value to the grid relative to the same backup requirements introduced with centralized fossil/nuclear?" (my wording).

It was to fill the gap between projected wind and actual wind. Simlarly, the carbon intensity data (the actual purpose of the study) was just attempting to measure the inefficiency involved in running fossil plants less efficiently when they're balancing wind generation. It wasn't a measure of carbon emissions from plants that are running when the wind isn't blowing (unless it was predicted to blow and didn't).

Where, other than in your imagination, does the OP say anything else?

I expect that this could vary considerably from one scenario to the next... but it should always be pretty small compared to total wind generation. But it tells us nothing about how much backup generation is needed for high penetrations of renewables.

It wasn't claiming to, it speaks only to wind. Also. it would depend on what is meant by "how much" - in absolute terms no, it doesn't inform the discussion specifically. But in terms relative to what is required for a fossil fuel based system it is very informative, since that is the information it was designed to deliver.

There's really nothing new here.

Yes, there is. The finding that such a minute amount of inefficiency is created is good news. Also the amount of back up relative to that required by fossil fuels for the same grid variability problem is new (and very good) information.

Your entire screed is based on several red herrings and omitting key discussion points, so, again, please provide support DIRECTLY from the source document the next time you are tempted to falsify something.

[Fridap]

16. One commendation, some caveats

The National Grid study, found at the link provided by GBaggins, http://www.scottish.parliament.uk/S4_EconomyEnergyandTourismCommittee/NATIONAL_GRID.pdf, made a commendable effort to look at fuel consumption relative to electricity generated (ie, efficiency), but it looked only at combined-cycle gas turbine (CCGT) plants and not at coal as well.

And in estimating the efficiency of the gas plants, it appears that the analysis looked only at the times when they were generating electricity. If so, it did not in fact consider fuel deliveries when a plant was not generating electricity, ie, fuel consumption while on standby or startup/shutdown. CCGT plants are not able to ramp as quickly as open-cycle plants.

FYI, at the moment, the British grid stats are (http://www.bmreports.com/bsp/bsp.php#generation_by_fuel_type_table):
Total generation: 41470 MW
Wind production: 2371 MW (5.7% of generation; 23.2% of installed capacity)
Coal: 14739 MW (35.5%)
Nuclear: 7104 MW (17.1%)
CCGT: 12672 MW (30.6%)
OCGT: 0 MW (0.0%)

[kristopher]

17. That isn't true.

They looked at both gas and coal.

...The volume of energy generated by wind farms in Great Britain is shown in Table 1. This has been broken down into the three most recent six monthly periods. If the wind farms that generated this energy had not been constructed this energy would have been generated by what would have been the next most economic generator. From October 2011 to September 2012 this would likely have been a Combined Cycle Gas Turbine (CCGT)3. From April 2011 to September 2011 the marginal generator could equally have been a CCGT or a coal fired generator4. An average carbon intensity for gas and coal has been used for this period. It is assumed that CCGT’s emit 392 tonnes CO2/GWh5 and coal fired generators emit 912 tonnes CO2/GWh5 of electricity generated.

And with their methods they would have captured any efficiency effects in the standby and ramping phases as well.

by analysing the amount of electricity generated by gas fired power stations and comparing it to the volume of gas consumed by the same stations.

If inefficiencies were introduced at any stage a comparison of the amount of fuel with output would capture it in the same way that idling your car at stoplights would impact your mileage ratings.

[Fridap]

18. Yes it is.

What you are quoting is how they estimated theoretical CO2 savings by assuming a simple one-for-one replacement of kWh's produced by an average mix of rampable generators. The efficiency part examined only CCGTs (see quote below; Britain doesn't seem to use OCGTs).

As for the efficiency estimates, as I said, it is unclear:

"Half-hourly or Daily Data on the efficiency of thermal generation stations is not readily available. Therefore, for this analysis an approximation of the efficiency of gas fired plant has been made by analysing the amount of electricity generated by gas fired power stations and comparing it to the volume of gas consumed by the same stations."

That suggests that they looked at generation first, and then matched as best as they could the delivery of gas during that time in an effort to look at, not overall production and consumption (like your car's overall average mpg), but consumption during production (like checking the instantaneous mpg on your car while moving), which is, after all, what is meant by "efficiency". But, again, it is not clearly enough described to be sure one way or the other.

[kristopher]

19. They included coal where it needed to be included.

You are cherry picking a statement from one section and grossly overstating its meaning. They looked at coal as part of the mix and made adjustments to the carbon intensity numbers that would appropriately account for the percentage of coal in the mix.

The entire approach used is well regarded. It is based on basic chemistry and isn't amenable to creative speculation or error.

This conclusion you've developed isn't accurate. "That suggests that they looked at generation first, and then matched as best as they could the delivery of gas during that time in an effort to look at, not overall production and consumption (like your car's overall average mpg), but consumption during production (like checking the instantaneous mpg on your car while moving)."

It is exactly the opposite as their method weighs three areas to arrive at final numbers that are, in fact overall numbers (not "instantaneous&quot :

1. Direct carbon emissions reduction estimated through the total volume of energy generated by wind farms.
2. Volume of gas used by Generators compared with the amount of electricity generated over time to determine whether the intermittent nature of wind generators’ output has affected the carbon intensity of the generation fleet.
3. Calculation of indirect carbon emissions arising from energy generated by Short Term Operating Reserve that is estimated to be due to real time wind output being less than forecast.

Accommodations for coal's emissions were made in sections one and three; it wasn't required in section 2, where you selected the quote from. The only ambiguity noted in the paper is the impact of the pipeline temperature* on the density of the natgas fuel. Given the overall low values of the results, that would seem to be an insignificant factor that could be expected to have little impact on the overall conclusions of the paper.




*See also http://www.nationalgrid.com/uk/Gas/OperationalInfo/operationaldocuments/linepack/

[Fridap]

20. Only section 2 examines "efficiency"

And as I have edited to clarify my previous note, "efficiency" implies "instantaneous" production vs consumption.

Section 2 is the only one that attempts to actually measure the issue at hand. Sections 1 and 3 make theoretical estimates only. So it is definitely a shortcoming of the section 2 analysis that it looked only at gas, and its lack of clarity about methodology definitely lessens the value of even those results.

[kristopher]

21. As the bandleader said "Once again with gusto"

I've already pointed this out, they didn't look at coal in section two because coal is not cycled - they don't attempt to run it up and down to follow variations in demand or load.

The only place coal is relevant are the times when (sec 1) it is displaced by wind - which isn't a cycling process - or when (sec 3) it is being held in reserve status to be turned on in a pinch.

Apparently you don't understand the method of analysis used (or, given that your purpose in coming to DU was overt support of a Koch Brother initiated and funded antiwind group, you are simply here to attack wind).

[PamW]

22. Actually it is...

kristopher states
The only place coal is relevant are the times when (sec 1) it is displaced by wind - which isn't a cycling process

Actually it is a cycling process. As anyone knows; wind power is not constant. The speed of the wind goes up and down from moment to moment. All one has to do is get a handheld wind meter and stand out anywhere and record the indicated wind speed from moment to moment.

The power produced by a wind turbine is proportional to the third power ( cube ) of the wind speed. So the wind speed is varying from moment to moment. The fact that you cube the wind speed to get the power means that the variation in power is even greater than the variation in wind speed.

As the wind power fluctuates; that fluctuation has to be compensated for so that power generation is equal to demand at all times as required by the Physics principle of conservation of energy. The coal plant is a "dispatchable" power generator and will compensate for the fluctuation in the wind turbine power output.

That variation in the output power of the coal plant is not done by the coal plant operators; it is done automatically by the turbine-generator speed regulation feedback. When the wind turbine power declines with wind speed; and if the demand doesn't change; that means there is a mismatch between power generated and power demand. The turbine-generator is synched to the power line; so when there is a mismatch in power generated vis-a-vis demand; Lenz's Law acts to slow down the turbine-generator. The plant has a feedback circuit that monitors the turbine-generator speed to keep it constant and synched. That feedback circuit alters the power of the powerplant to adjust for the shortfall caused by the wind turbines.

Non-dispatchable energy sources like wind and solar that are subject to moment to moment variations in their power output; need to have a backup from a dispatchable power generator.

That's why no less than the National Academy of Sciences states that we have to have some form of dispatchable energy supply to backup renewables like wind and solar, and the discussion is always improved by correcting misinformation.

The good thing about science is that it is true whether or not you believe in it.
--Neil deGrasse Tyson

PamW

[kristopher]

23. That has nothing to do with the discussion point at hand.

As you wrote:

That variation in the output power of the coal plant is not done by the coal plant operators; it is done automatically by the turbine-generator speed regulation feedback.

This is what the study is concerned with:

Introduction
Electricity Suppliers purchase electricity that they forecast their customers will use from Generators. Generators notify their consequent expected output profile to the NETSO and self-dispatch their plant to meet this profile. If necessary, the NETSO accepts bids and offers1 from Generators to alter their output to ensure that actual electricity demand is met in real time. In addition the NETSO ensures that there is an appropriate amount of generating capacity (reserve) above and below forecast demand. This capacity ensures that the system remains secure, within a defined set of criteria, if the demand turns out to be higher or lower than forecast, if there are generation losses, if there are demand losses

In summary the carbon penalty associated with wind was only 8/10s of one percent of the amount of carbon reductions it enabled.

10,900,000,000,000 tons reduced
_____8,800,000,000 ton penalty

For a net reduction of 10,891,200,000,000 tons

Another right wing, pronuclear, antirenewable talking point bites the dust.

[Fridap]

24. You're going in circles

and unfortunately now lashing out polemically instead of with your up to now attempt at rationality.

As you note in your quote, there is a certain reserve capacity kept ready — "spinning" — to kick into generation when a plant or transformer fails. That is exactly what wind energy takes advantage of in this analysis. While wind's "penetration" is well below that percentage reserve, it doesn't strain it too badly: There's enough to cover for wind's dips and rises. On the other hand, it is clearly dishonest to then claim the theoretical CO2 savings according to generation instead of actual fuel consumption.

As I first said, it is commendable that the National Grid made an effort to look at actual fuel consumption. But I also noted that the cited paper is not all that clear about how exactly they looked at it. As an agency of a government committed to proving the viability of wind power, it is not unreasonable to question that ambiguity.

Calling your correspondents names (particularly when so far off the mark) does not bolster but rather diminishes your own argument.

[kristopher]

25. That is gibberish

What you wrote literally has no meaning as a critique of the study.

You wrote:

As you note in your quote, there is a certain reserve capacity kept ready — "spinning" — to kick into generation when a plant or transformer fails. That is exactly what wind energy takes advantage of in this analysis. While wind's "penetration" is well below that percentage reserve, it doesn't strain it too badly: There's enough to cover for wind's dips and rises. On the other hand, it is clearly dishonest to then claim the theoretical CO2 savings according to generation instead of actual fuel consumption.

"As you note in your quote, there is a certain reserve capacity kept ready — "spinning" — to kick into generation when a plant or transformer fails."
- Partially true. It's also there to respond to rapid changes in demand


"That is exactly what wind energy takes advantage of in this analysis."
- If, by "take advantage of" you mean this is the way the grid responds to variability and wind is one of many forms of variability - then yes, that is also true.


"While wind's "penetration" is well below that percentage reserve, it doesn't strain it too badly: There's enough to cover for wind's dips and rises."
- "Penetration" is a term used to refer to the amount of installed capacity of a given resource relative to other sources. It implies that the amount varies based on a developing market. So your statement is saying:


"While the amount of installed wind is well below that percentage reserve, it doesn't strain it too badly: There's enough to cover for wind's dips and rises."
- I don't understand how the amount of installed wind can be "well below that percentage reserve". That makes no sense any way I charitably try to consider it. The amount of reserve is set with formulae that account for expected variables. If you find a place where the amount of this reserve is compared to wind's penetration, I'd love to see it.


"On the other hand, it is clearly dishonest to then claim the theoretical CO2 savings according to generation instead of actual fuel consumption."

This can in no sense flow as an "on the other hand" comment from its antecedents in the paragraph. It is a (false) conclusion you've attempted to make credible with the above gibberish.

The FACT is that the study is solid, your antiwind efforts to disparage it notwithstanding.

[Fridap]

32. The study most certainly is NOT solid

for the reasons I noted. Its findings may be true, but based on the information provided they are questionable. The primary rationalization of wind power is to meaningfully reduce CO2 emissions (in the face of lifestyle/economy change being nonnegotiable), so the simple measure is fossil fuel use per unit of electricity consumed. This study appears to look at that measure in its section 2, but then it looks only at natural gas delivery, and possibly only while the gas plant is generating electricity. In short, it avoids the simple analysis, and one must assume that it does so to avoid that simple analysis. It's not hard; see, eg, http://kirbymtn.blogspot.com/2008/02/uk-fossil-fuel-use-for-electricity-2002.html

[kristopher]

36. More Koch Sucking Bullpucky

You have expressed no valid criticisms of this study.

None.

Not one.

So when you say "...not solid for the reasons I noted" you are doubling down on nothing.

The only thing you've shown is that you are either very uninformed or deliberately trying to obscure facts.

[Fridap]

37. Potty-talking bluster

It all descends to that with you, doesn't it. Because in fact, you can't find a single study (of actual data, not theory) showing a meaningful decline in fossil fuel use per unit of electricity consumed because of wind power, can you.

One might even characterize such adamant wind promoters like yourself as dupes of the fossil fuel industry, distracted by (fossil-fueled) fantasy rather than fighting for actual reductions in energy use. You would appear to support Dick Cheney that our way of life is nonnegotiable.

[PamW]

27. Actually...

Last edited Sat Oct 5, 2013, 08:53 PM - Edit history (3)

The coal power plants are changing their power.

It's not being done by the operators toggling switches in the control room.

However, the coal power plants are changing their power and cycling in order to follow the load / demand as the wind turbines fall behind the demand due to variable wind conditions.

The extra capacity in the coal power plant that it is using to compensate for the shortfalls of the wind turbines is part of the utilities "spinning reserve". It's reserve capacity in the coal power plant, and it's "spinning" because it's ready to compensate for the shortfall of the wind turbines instantly. There's no need to "spin up" any new equipment to compensate for the wind turbine's shortfall.

http://en.wikipedia.org/wiki/Operating_reserve

The spinning reserve is the extra generating capacity that is available by increasing the power output of generators that are already connected to the power system. For most generators, this increase in power output is achieved by increasing the torque applied to the turbine's rotor

( Actually that should be "the torque applied by the turbine's rotor. It's the turbine's rotor that is applying torque to the generator. What is being applied to the turbine is increased steam pressure and/or mass flow rate )

In addition, there is the "frequency response" reserve; which is the extra capacity available to correct for supply / demand mismatches that would otherwise drive the generator out of sync.

The frequency-response reserve (also known as regulating reserve) is provided as an automatic reaction to a loss in supply. It occurs because immediately following a loss of supply, the generators slow down due to the increased load. To combat this slowing, many generators have a governor. By helping the generators to speed up, these governors provide a small boost to both the output frequency and the power of each generator.

It really does help to know how electric grids / power plants work in order to interpret the study; flawed though it be.

The good thing about science is that it is true whether you believe it or not.
--Neil deGrasse Tyson

PamW

[kristopher]

29. You are right again...

..."it really does help to know how electric grids / power plants work".

We can also add to that how studies are planned and performed.

There are places where coal is a preferred rapid cycling technology. But that is a rather rare role for coal to play - but it does happen. For example, in Germany the new coal plants they built are designed for fast ramping and the ones they are shutting down are apparently older and less flexible.
However, it is much more common for the fast ramping to be accomplished by natgas.
Much more common.

Which means that, in this case, coal probably isn't a factor in the areas of the analysus where they have not included an accounting of its emissions.

Unless you have some evidence that they are hiding something, your posts are still not relevant and are clearly intended only to muddy the waters.

The study is solid, and there is no reason to doubt its conclusions - unless you are a right wing, nuclear-loving zealot, in which case "reason" is out the window in any case.

[PamW]

33. It does help to understand how plants work..

The coal plants are cycling and adjusting power as there are shortfalls in production by non-dispatchable renewables; mainly wind / solar.

What big thermal plants like coal and nuclear have problems with are rapid changes in temperature, not power, when it really comes down to it. However, you can change power without changing temperature.

The energy contained in a mass of material is proportional to the specific head times the mass times the temperature. Mathematically:

E = C * m * T

Now power is the temporal rate of change of Energy, that is the temporal derivative of Energy. Although the specific heat does depend mildly on the material's state, it's a second order effect, and let's assume for the moment that the specific heat C is constant. If we then differentiate the energy to get the power:

P = dE/dt = C * ( dm/dt * T + m * dT/dt )

which we get from the product rule of differentiation.

We can increase the power by making the temperature differential dT/dt larger while holding the mass flow rate constant. However, we can also get a larger power by holding the temperature T constant and increasing the mass flow rate dm/dt.

Again, what the large thermal plants have problems with is changing temperatures quickly; because that causes various components to expand / contract quickly. However, we can hold temperatures constant and increase power by increasing flow rates.

It really does help to understand the physics of electric power production when interpreting studies.

As the saying goes;"I can explain it to you; but I can't understand it for you"

The good thing about science is that it is true, whether you believe it or not.
--Neil deGrasse Tyson

PamW

[kristopher]

35. Which is why your attempt at deflection is without merit

And natural gas is the preferred fuel for load following.

[kristopher]

26. Similar study from NREL

NREL Calculates Emissions and Costs of Power Plant Cycling Necessary for Increased Wind and Solar in the West
Study finds that cycling fossil-fueled power plants has little impact on avoided emissions but modestly increases wear-and-tear costs.

That's from NREL's home page for studying renewable integration (lots and lots of material here -http://www.nrel.gov/electricity/transmission/western_wind.html

Caveat - this study is specific to the grid conditions of the Western US and may not be true for all areas.

The Western Wind and Solar Integration Study Phase 2
An examination of how wind and solar power affect operations, costs, and emissions from fossil-fueled generators

The electric grid is a highly complex, interconnected machine. Changing one part of the grid can have consequences elsewhere. Adding variable renewable generation such as wind and solar power affects the operation of the other types of power plants, and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions, but do those increases in costs and emissions from cycling negate the overall benefits of integrating renewables?

Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) was initiated to determine the wear-and-tear costs and emissions impacts of cycling and to simulate grid operations to investigate the detailed impacts of wind and solar power on the fossil-fueled fleet in the West. It was a follow-up to Phase 1 (WWSIS-1), released in May 2010, which examined the viability, benefits, and challenges of integrating high penetrations of wind and solar power into the Western grid. WWSIS-1 found it to be technically feasible if certain operational changes could be made, but it raised questions regarding the impact of cycling on wear- and-tear costs and emissions.

Purpose of the Study

Frequent cycling of fossil-fueled generators can cause thermal and pressure stresses. Over time, these can result in premature component failure and increased maintenance and repair. Starting a generator or increasing its output can increase emissions compared to noncyclic operations. Further, operating a generator at part-load can affect emissions rates. Utilities are concerned that cycling impacts can significantly negate the benefits that wind and solar power bring to the system. To plan accordingly, power plant owners need to understand the magnitude of cycling impacts.

Key Findings
• The negative impact of cycling on overall plant emissions is relatively small. The increase in plant emissions from cycling to accommodate variable renewables are more than offset by the overall reduction in CO2, NOx, and SO2. In the high wind and solar scenario, net carbon emissions were reduced by one third.

• Operating costs increase by 2% to 5% on average for fossil fueled plants when high penetrations of variable renewables are added to the electric grid. From a system perspective, these increased costs are relatively small compared to the fuel savings associated with wind and solar generation.

• Wind and solar impact gas and coal plants very differently. Adding 4 MWh of renewable generation displaces 1 MWh of coal generation and 3 MWh of gas. Wind tends to reduce generation from combustion gas turbines, while solar tends to increase starts and ramps of gas turbines to meet peaks that occur at sunset. The most significant cycling impact from increased wind and solar is the increased ramping of coal plants.

Adding 4 MWh of renewable generation displaces 1 MWh of coal and 3 MWh of gas generation.

“Grid operators have always cycled power plants to accommodate fluctuations in electricity demand as well as abrupt outages at conventional power plants. Increased cycling to accommodate high levels of wind and solar generation increases operating costs by 2% to 5% for the average fossil-fueled plant. However, our simulations show that from a system perspective, avoided fuel costs are far greater than the increased cycling costs for fossil-fueled plants.” – Debra Lew, PhD

From PDF summary at http://www.nrel.gov/docs/fy13osti/57874.pdf

[PamW]

28. Crutches for the renewables.

Exactly; even NREL states that, in effect; renewables like wind and solar are using the "dispatchable" power plants like coal, gas, hydro, and nuclear; as a "crutch". The dispatchable power plants are compensating for the moment to moment variations in non-dispatchable renewables.

If you kick the "crutches" out from under the non-dispatchable renewables like wind and solar; you don't have a way to respond to the instant by instant variation due to both load and the intermittent nature of the renewables and your grid will fail

PamW

[kristopher]

30. Uh, no.

If dispatchable power is a crutch for renewables it is also a crutch for thermal, since thermal needs more of it (see op) and it is a longstanding critical element of a centralized thermal grid.

A distributed renewable is conceptualized in an entirely different manner where dispatchable generation is far less critical because far more end use applications (particularly heating and cooling) will be designed to facilitate load shifting.

[Fridap]

31. Purely theoretical

The NREL "study" is a projection of theoretical estimates. It is not a study of actual experience.