Wind power not doing too well in the UK.

[TheMadMonk]

In general it tends to be assumed that a wind farm will generate an average of 30 per cent of its maximum capacity over time. However the new study shows that this is actually untrue, with the turbines measured by the Grid turning in performances which were significantly worse:

Average output from wind was 27.18% of metered capacity in 2009, 21.14% in 2010, and 24.08% between November 2008 and December 2010 inclusive.

In general, then, one should assume that a wind farm will generate no more than 25 per cent of maximum capacity over time (and indeed this seems set to get worse as new super-large turbines come into service). Even over a year this will be up or down by a few per cent, making planning more difficult.

It gets worse, too, as wind power frequently drops to almost nothing. It tends to do this quite often just when demand is at its early-evening peak:

At each of the four highest peak demands of 2010 wind output was low being respectively 4.72%, 5.51%, 2.59% and 2.51% of capacity at peak demand.

http://www.theregister.co.uk/2011/04/07/wind_power_actually_25_per_cent/

Also windpower is all too often used to generate Renewable Offset Certificates at times of very low demand, actually paying other suppliers to get off the grid. The ROCs are later used to avoid fines when generating primarily with polluting sources.

[geckosfeet]

1. Put them where there is a lot of wind. Average output will be higher.

I am not a rocket scientist or brain surgeon, but I would guess that if the 'wind power frequently drops to almost nothing', it suggests that the turbines are not spinning - most likely due to lack of wind.

My thought has always been that efficient energy sources are specific to the region - that is - solar in the mid latitude deserts and plains, hydrothermal where steam vents and hot springs are in the open, wind at higher elevations and in historically windy areas, tidal on the shore and so on.

We need to make efficient use of these energy sources - the oil supply chain is becoming more expensive every second.

[Bosonic]

2. Apparently the UK is the 'windiest' European country

http://www.edie.net/news/news_story.asp?id=16190
http://edition.cnn.com/BUSINESS/programs/yourbusiness/stories2001/windiest/

So maybe they need to look at the design of the existing turbines?

[kristopher]

4. Actually the study has a bit of ambiguity...

No study is perfect and this one was done using easy to access data that may or may not be representative of the actual state of the wind output actually delivered. It is a good study for what it is, though. It is normal to use data like that when doing a first cut investigation of an issue. If results like this are reported those results need to be looked at more closely by people with more expertise and resources to see if 1) there is a problem, then 2) accurately define where the problem lies.

See post #3 for more details.

[kristopher]

3. Interesting, but it isn't possible to assess the validity of this study without more information.

I can see a few things to pick at, such as ambiguous language in one spot that will probably be misread to worsen the impression of wind. But on the real substance of the report I'd have to look at a couple of things that I didn't find.

First is the layout of the wind farms that were included in the study in relation to the known prevailing wind patterns. The use of wind is maximized across specific geographic areas with a specific configuration that follows prevailing winds. If you take a set of wind farms that transect the established pattern, you'd be expected to get poorer results than if you select the set designed to be managed together. Wind forecasting is a critical part of grid management involving wind and its effects would not be captured in this type of analysis. There is a discussion of this in the paper
Electric power from offshore wind via synoptic-scale interconnection (Kempton etal)
http://www.pnas.org/content/early/2010/03/29/0909075107.abstract

Next point also involves the data sample - they don't have data on about half of the installed wind feeding into the grid. That seems particularly problematic to their conclusions regarding both the average capacity factors achieved and the overall availability of wind as part of the grid. They used wind turbines that are direct connect to the grid - ones that the grid can "see" as they put it, "If a wind farm connects to a substation owned or operated by NG, NG can “see” it. If it simply hooks into the wider distribution system, NG cannot “see” it."

Being that most major wind farms are connected to internal substations owned and operated by the wind farm operator, this sampling selection would appear to favor small operations where the power isn't aggregated before being delivered to the grid's substation. That, in turn, means that the sample might possibly favor the least productive of the installed capacity. It would require a far more rigorous review to know for sure, but this unresolved selection bias cast sufficient doubt on the conclusions to warrant skepticism until further research either confirms the findings or negates them.

Finally the other issue that needs to be looked at to put the study into perspective is how the wind turbines in the study were promoted and what incentives drove the development. It is completely possible for perverse incentives to drive development of sub-optimum wind sites and that possibility would have to be examined and discounted before the broader conclusions of the study were validated.

Interesting paper, but it reminds me of an economic analysis that was funded by the Kochs in Spain claiming that subsidies on renewables were counterproductive to job growth. It was poorly done and could not be considered valid.

This paper's shortcomings may or may not have a similar impact on the conclusions, it isn't possible to tell without more detailed investigation of the study. It does, however, justify further examination, and the claims discussed, by rights, should also prompt a more rigorous examination. I look forward to seeing the response it elicits from those more familiar with wind in Scotland than I am.

[TheMadMonk]

5. With fifty percent of the capacity, it's a fair first approximation...

...to assume (all else being equal) that the other half will be more or less the same for comparative purposes.

Solar, tide, even wave are at least predicable and periodic enough to make it a hell of a lot easier to plan ahead for getting the power to WHERE it is needed WHEN it is needed.

Management of wind power as it stands right now is almost totally reactive, and it's more valuable for dodging punitive tarrifs than as a truly viable alternative generating capacity.

The new turbine designs seem wonderful until you realise the big ones will be visible from 20 miles or more away. The kites further still.

There may well be flaws, but nothing which would invalidate the basic conclusion.

[kristopher]

6. I disagree, it is not a fair approximation. It has some merit, but only to raise questions.

You make this statement of opinion as if it were fact: "Management of wind power as it stands right now is almost totally reactive, and it's more valuable for dodging punitive tarrifs than as a truly viable alternative generating capacity."

That is pure hogwash. If you can support it you should do so, because the best experts in the field of grid reliability and integration of variable resources disagree with your claim.

Wind Power Myths Debunked
By Michael Milligan, Kevin Porter, Edgar DeMeo, Paul Denholm, Hannele Holttinen, Brendan Kirby, Nicholas Miller, Andrew Mills, Mark O’Malley, Matthew Schuerger, and Lennart Soder

Digital Object Identifier 10.1109/MPE.2009.934268 november/december 2009 1540-7977/09/$26.00©2009
IEEE Power and Energy Magazine Master Series


Questions addressed:

Can Grid Operators Deal with the Continually Changing Output of Wind Generation?

Does Wind Have Capacity Credit?

How Often Does the Wind Stop Blowing Everywhere at the Same Time?

Isn’t It Very Difficult to Predict Wind Power?

Isn’t It Very Expensive to Integrate Wind?

Doesn’t Wind Power Need New Transmission, and Won’t That Make Wind Expensive?

Doesn’t Wind Power Need Backup Generation? Isn’t More Fossil Fuel Burned with Wind Than Without, Due to Backup Requirements?

Does Wind Need Storage?

Isn’t All the Existing Flexibility Already Used Up?

Is Wind Power as Good as Coal or Nuclear Even Though the Capacity Factor of Wind Power Is So Much Less?

Isn’t There a Limit to How Much Wind Can Be Accommodated by the Grid?

Wind Power Myths Debunked
Common Questions and Misconceptions
Introduction:
THE RAPID GROWTH OF WIND POWER IN THE UNITED STATES AND worldwide has resulted in increasing media attention to — and public awareness of — wind generation technology. Several misunderstandings and myths have arisen due to the characteristics of wind generation, particularly because wind-energy generation only occurs when the wind is blowing. Wind power is therefore not dispatchable like conventional energy sources and delivers a variable level of power depending on the wind speed. Wind is primarily an energy resource and not a capacity resource. Its primary value is to offset fuel consumption and the resulting emissions, including carbon. Only a relatively small fraction of wind energy is typically delivered during peak and high-risk time periods; therefore, wind generators have limited capacity value. This leads to concerns about the impacts of wind power on maintaining reliability and the balance between load and generation.

This article presents answers to commonly asked questions concerning wind power.

It begins by addressing the variability of wind and then discusses whether wind has capacity credit. The article addresses whether wind can stop blowing everywhere at once, the uncertainty of predicting wind generation, whether it is expensive to integrate wind power, the need for new transmission, and whether wind generation requires backup generation or dedicated energy storage. Finally, we discuss whether there is sufficient system flexibility to incorporate wind generation, whether coal is better than wind because coal has greater capacity factors, and whether there is a limit to how much wind power can be incorporated into the grid...

http://www.scribd.com/doc/49247528/wind-myths

BTW, Compare these real studies on the topic with pieces like the one you offered. There is some value to having outside agents look at the issues, but it is also valuable to know how those outside analysis fit into the broader body of knowledge. Go here and search the authors names from above for a sample of the information the "myths" paper is based on. Recommend starting with Milligan.
http://nrelpubs.nrel.gov/Webtop/ws/nich/www/public/SearchForm

[txlibdem]

11. Kris, you yourself have posted a number of studies that show only up to 20% wind or so

can be integrated into the grid with present grid management practices.

The UK has so much wind potential (see my earlier post for the offshore and onshore wind maps) that it should easily be able to get the majority of its energy needs from wind and wave power. This will exceed the ability of grid managers to integrate wind because of the fluctuations in electrical output.

Some form of energy storage is going to be needed, of that I have no doubt. Whether it be a centralized unit, or regional, or at each wind farm, it makes no difference to me. Storage will be needed and over-capacity will be needed. These studies need to be unbiased and accurate so that nations can plan for the actual storage needs and not rely on industry fluff pieces or "blue sky" predictions of energy output. Much more study is needed, none of which should come from the industry itself.

[Name removed]

14. Deleted message

Sub-thread removed by moderator. Click here to review the message board rules.

[Confusious]

21. They have all that they can meter

It says in the report "National Grid can only meter windfarms connected directly to the Grid, not those embedded in the wider distribution network." pg 26, notes.

[FBaggins]

24. How confident are you on the substation/grid point?

I thought it was smaller plants that weren't connected directly to the grid because the turbines produced D/C and needed to run through an inverter... while larger turbines produced A/C and were connected directly to the grid.

[txlibdem]

7. It's a first step toward getting accurate performance data

Much more study is needed, IMO, but I welcome this as a first step.

The UK does seem to have the best offshore wind potential in Western Europe. Here is a map of offshore winds, showing wind speeds at 5 different elevations:
http://www.windatlas.dk/europe/oceanmap.html

Onshore wind is also a great resource that Britain should be taking full advantage of:
http://www.geni.org/globalenergy/library/renewable-energy-resources/world/europe/wind-europe/index.shtml
... you have to scroll down about 2/3rds of the page to see the Wind Map of Western Europe. It shows that the entire coast of Ireland, all of Scotland, the coasts of Norway, Sweden, and Finland are very well suited for wind farms (have the highest wind speeds).

[kristopher]

8. This isn't a "first step"; it is an outlier.

It is making claims that contradicts other research.
It has some very obvious methodological weaknesses.
At best, it is an interesting tidbit to be looked into by those who have familiarity with the specific system being examined.
At worst, it is just another paid anti-renewable hit piece.

It merits a serious look, but at this time it has very little credibility.

[txlibdem]

9. How does a factual analysis make it a hit piece?

Accurate data is a must for any industry to improve its products, and is a must for any utility seeking to use said products.

The 21% to 27% figure may not jibe with what you've been reading but that does not make it inaccurate. Further study is definitely needed.

PS, I do not really understand how the mere fact that a wind farm has it's own substation causes it to be unreadable, or unavailable for inclusion in a study. Someone has that data and should be able to provide it. After all, the utility pays the wind farm owner for the exact amount of electricity actually delivered to the grid, not just a "wink and a promise" of x number of kilowatt hours.

[kristopher]

12. I described the problems with the study in post #3

There is a serious bias in the sample selection that should have been addressed in the paper. The author knows it is there (he specifies his sampling method) yet he has not addressed the implications at all - an act that is bad research at best, and outright fraud at worst. If the paper has knowingly used a data set that represents the worst performing turbines that have been installed (which seems to be a reasonable interpretation of the evidence) then the omission of a discussion on the nature of what is and is not "seen" by the NG is fraud.
If the omission is inadvertent, it is shoddy work. Either way the credibility of the paper is seriously compromised by the act of omission.

If you require it we can have this same discussion another 5 or 10 times.

[txlibdem]

16. Only what is "seen" by the NG, yes, but if you read on...

From the 28 page PDF:
NG can “see” around 50% of all industrial UK wind generation. There is no reason to believe that
wind generation not “seen” by NG performs any more efficiently. Indeed, it is possible that, since
all the onshore wind generation in the metered total is presently in Scotland, which is generally
windier than the rest of the UK, the “unseen” wind generation may perform less well.
Until July 2010, all wind generation “visible” to NG, and in the data analysed in this Report, was
from onshore wind in Scotland. It represented about 80% of all industrial wind generation in

Scotland and had a good geographical spread. It is reasonable to assume, due to the good
geographical spread, that the “visible” generation was a fair representation of all generation in
Scotland at that time.
... http://www.jmt.org/assets/pdf/wind-report.pdf
---------------------------------

Scotland is the windiest part of the UK, the data covers about 80% of wind generation in Scotland. I just don't see where a bias could be possible.

Your posts seem to suggest that they "cherry picked" the worst wind farms to include in the study but from reading the study I see no evidence of that. In fact, I tend to agree with the authors that if anything they are biasing upward, not downward by having all the data from 2008 until July 2010 coming from the windiest part of the nation.

It doesn't fit with your claim that no storage is needed for wind. I tend to disagree with you on that. Britain already has 2.7GW of storage in the form of pumped hydro enough for 5 hours when it is reduced to 1.6GW that lasts up to 22 hours total. The study also says that 124 separate occasions where the power output from all wind turbines in the study was less than 20MW (out of 1600MW+ nameplate capacity), which is 1.25% of nameplate. But these averaged less than 5 hours so the current 2.7GW of hydro storage in Britain should be adequate to allow at least a doubling of their wind power with no further storage required. Anything beyond that, however, will require additional storage to be built and the costs of that should be fairly represented by the wind industry and not swept under the rug.

[Confusious]

22. He took every wind farm he could meter

It says in the report "National Grid can only meter windfarms connected directly to the Grid, not those embedded in the wider distribution network." pg 26, notes.

You must not have even looked at the report.

[Confusious]

19. It makes renewables look bad

Therefore it must be discredited. Any "study" that does not conclude that renewables, in this case wind, work 100% of the time and have no drawbacks are blasphemy.

[txlibdem]

20. That is why I am confused by all the attacks on the OP

The truth will come out at one point or another. Wind cannot be the only source of energy and it's easy to prove it by looking at the meteorological data for any area.

That is why I always state my opinion that for now the proper energy mix is 40% nuclear and 60% renewable energy sources with proper amounts of excess capacity and storage so as to be reliable 24/7/365, not just "when conditions are perfect."

Thankfully, here in America, we have a vast south west desert that could supply solar, wind corridors offshore in the Pacific and the Atlantic plus onshore in a vast area that stretches from west Texas to Canada. With adequate storage and excess capacity, both could work together to provide the energy when the other lags. Then we have geothermal, tidal and wave power. And anything that needs a liquid fuel or plastic can be made from bio fuels derived from cellulosic or algae (not corn). Throw in a few million electric cars each year and the world will be off its addiction to coal and oil before you know it.

Then we can begin replacing the nuclear power plants with renewable energy. This is doable. By 2020 we will have all the technologies we need. We already have the technology to get to 50% renewables. We should be moving boldly forward.

[madokie]

25. Do you really think that anyone thinks or proposes that wind is 100%

or that solar is likewise? :rofl:

[Confusious]

27. The way some of you act,

and the ways you come up with to make it sound like it isn't so, yes. Have an doubts about the church of renewables, and you've bespoke blasphemy. (Interesting. bespoke isn't flagged by spell check)

Reminded about a post here a while back, and the person, who supports renewables, was arguing that capacity factor doesn't matter. Baseload doesn't matter. ??

"The wind is always blowing somewhere and the sun always shines"

Sound familiar? Maybe it's not a lack of understanding on my part, maybe it's a lack of communication on yours. Maybe it's neither. Maybe some of you have no doubts AT ALL whether renewables will be able to fill the gap. Is it based on knowledge or just faith? Seems more faith then anything to me. ( adding in capacity factor, land requirements, material requirements, money requirements, it doesn't paint a pretty picture. Maybe survivable, but debatable)

Haha.

[XemaSab]

10. You don't think these numbers are accurate?

The volatility of wind was underlined in the closing days of March 2011 as this Report was
being finalised.

• At 3.00am on Monday 28 th
March, the entire output from 3226MW capacity was 9MW.
• At 11.40am on Thursday 31st
March, wind output was 2618MW, the highest recorded to
date.
• The average output from wind in March 2011 was 22.04%.
• Output from wind in March 2011 was 10% of capacity or less for 30.78% of the time

[kristopher]

13. What about the other 50% of wind turbines that were not in the study?

Why were they not in the study?

The group that was included in the study was included because they share a common architecture for integrating with the grid.

The group that was excluded also share a common architecture for integrating with the grid.

The common factor of the included group is, as far as I understand, something that would be found in small scale projects that do not aggregate the output of a large number of units before shipping the power to the grid. Therefore the projects are probably small scale, lower budget and on the lower end of the productivity range.

The common factor for the other group is that they DO channel their output into a substation that is owned and operated by the wind farm operator where the power is aggregated into a smoothed product that can integrate directly into the grid. This represents a substantial investment and would mark the turbines in this set as being (probably) larger scale, with higher budgets and on the higher end of the productivity scale.

I'm not an expert on wind power in Scotland, and the paper should be (and will be) examined by those that will know the details necessary to evaluate the paper.

The OP study also offers some extremely broad conclusions from such a slipshod analysis (see post #3 about wind predictions and management of wind power).

I know the fission fans want to find a reason to challenge their competition, but you are going to have to either produce better propaganda or you are going to have to wait until this study is either confirmed or disproved.

[Confusious]

23. It says in the report

"National Grid can only meter windfarms connected directly to the Grid, not those embedded in the wider distribution network."

There's why. They also took 80% of Scotland. more omissions?

"The group that was excluded also share a common architecture for integrating with the grid."

Really? are you an expert in the UK energy grid also?

"I'm not an expert on wind power in Scotland, and the paper should be (and will be) examined by those that will know the details necessary to evaluate the paper."

So why are you saying they all have the same "common architecture" going into the grid?

[TheMadMonk]

26. Pre-agregate all you like. You can not properly smooth a mix of intermittent...

...supplies simply by adding the outputs together. NO WAY. NO HOW. Inductances and capacitances inherrent in the grid give it a certain inertia which allows it to smooth out varriances over timescales of a few seconds or less. However, beyond that considerable actual storage capacity is absolutely essential for buffering. (Right now the only thing being buffered is the generator's bottom lines.)

Without at least a tenfold (full security appears to demand a thirtyfold) increase on existing storage capacity, either a widespread calm, or a big storm (forcing turbines to stop) has the potential to take down a significant percentage of the grid if the UK were unable to make up the shortfall from elsewhere.

FFS there's enough long term variability to give any planner kittens. 21% - 27% year to year. Hmm, just how do you plan to force suppliers to maintain that much idle capacity? You won't. However their critical customers, who cannot withstand extended outages without ruinous losses, will quite cheerfully expect those suppliers to cut you and I off at the knees, to keep their businesses up and running. Oh and as often as not making good those ruinous losses will have been taxpayer guaranteed to attract the business to that location. Screwed and screwed are the likes of you and I.


One of the things I truly like about nuclear power is that its management really does begin with the very basic premise that people en mass are basically lazy, self-centred c*nts. Some enomous percentage of the rules, regulations and mandated procedures is entirely devoted to preventing people from being people as it were.

Conversely, the one thing which makes me aprehensive about the renewables hype is the degree of altruistic cooperation it absolutely demands from a wide range of entities with oftimes conflicting goals. I happen to like most of the renewable technologies on offer very much. It's their deployment model I am hating.

"The Grid" is as "The Grid" is. It is demand driven and there is no realistic way of changing that in the near future. If renewables are to fully replace polluting sources, they have to conform to the needs of "The Grid", they can't simply continue to jam in their contribution and expect "The Grid" to cope.


For my money the obvious solution is heat pumps. A pit of gravel can be burried anywhere. Beneath street intersections to capture the output of urban photovoltaics, returned in the evening when the the ACs come on, or even with the design of a proper urban understory "dumping the cold" into floorslabs and internal walls during the day killing the need for ACs almost entirely.

FFS why are we still installing infrastructure will he, nil she, one pipe and wire at a time? Take an ordinary urban street. trench out each sidewalk to a depth of 4 metres or so and cap it. Now install all utilities in one open tunnel. Easy service. Additional services become a snap and they're adding up fast: Power, Water (potable and non), stormwater, sewage, gas, phone (voice and data), with renewables it makes sense to include running "hot" and "cold".

Why not trench out the entire street and use it to catch stormwater runoff and store non-potable water for gardens and flushing?

2000+ years ago the Romans were building entire cities this way. Why the hell aren't we?

[Confusious]

28. Problems

"Why not trench out the entire street and use it to catch stormwater runoff and store non-potable water for gardens and flushing?"

Because that means more piping which means more money. The entire system is based off of clean water, dirty water. There's no piping for semi-clean water.

"2000+ years ago the Romans were building entire cities this way. Why the hell aren't we?"

No they weren't. They had fresh water brought in via aqueduct. The storm drains ran to the river. Sewage went to the river.

[TheMadMonk]

32. Take a look at Alexandria one day. Much of its Roman understory...

...remains functional today. I never said the Romans were up to modern hygiene standards. I said they built a comprehensive and coherent understory to their cities: Cisterns, sewers and drains, aqueducts, fountains, wells.

Just how much does it cost to dig half a dozen separate trenches, for half a dozen different utility services.

The one that really pisses me off when I see it, is where one utility comes late to the party in a new development and starts installing after the road's down. Every houseblock a patch (or even 2 a couple of metres apart) running across the full width of the road.

Whole roads would definitely be the province of new developments for now, but sidwalk trench tunnels are something which should be easily and affordably doable with enormous long term cost and maintenance benefits.

Playing fields and open parkland too would be ideal places to install underground stormwater cisterns even if roads are too radical. These days it is as simple as lining a hole with poly-ethylene plastic, filling it with milk crates and laying a cap and turf over the top.


Au contraire, there is plenty of fucking piping for semi-clean water. Virtually all of it devoted to throwing such water away.

And the extra piping for non-potable water returning (which you seem to imply is too expensive) is in fact going in, mostly in new developments for now, but also where there are major redevelopments happening as well.

All that's missing now is a way to gracefully combine stormwater runnoff with the non-potable water supply.

[Confusious]

33. Don't get me wrong, I agree with you, mostly

But that sort of thing takes a long time and planning, not the ad hoc way our cities are put together. We also don't live in a dictatorship, were someone can do as they please.

Adding those sorts of things to homes and laying pipe would be immensely expensive, first just laying the pipe and then hooking up homes to the pipes which don't have them already.

"Au contraire, there is plenty of fucking piping for semi-clean water. Virtually all of it devoted to throwing such water away."

And all of them connected to the sewage system. So how do you propose to separate the semi-clean from the not clean i.e. toilet water? There's also the matter of treatment. A lot of the water coming into the sewage system has to be treated, since it has all sorts of shit in it. What is the standard? and what if someone drinks from it?

[TheMadMonk]

35. Where I come from stormwater and sewage are kept separate.

It makes treating the sewage effluent up to non-potable water standards (which are in fact equal in all significant respects to potable standards here) a hell of a lot easier.

In the US (if a CSI episode is to be believed) non-potable water there is not necessarily the cleanest stuff in the world. I wouldn't bathe in it unless I had to and I certainly wouldn't drink it.

Australian "purple water" (pipe colour code) I'd drink without a qualm.


Oh separation. I forgot yet another utility conection which is making an appearance. Separating shit from urine at the source, because clean urine is in fact a highly valuable industrial precursor.


It's also enormously and increasingly expensive to route these services one at a time through the ever expanding ad-hoc underground maze when demand reaches critical thresholds. Even if it is only new developments to begin with, it makes sense to start doing things once instead of up to a dozen times.

[XemaSab]

36. What do you mean by "non-potable" water?

Do you mean heavy metals, pesticides, bacteria...?

I can't speak for the whole country, but most of the surface water here in California is safe to swim in. Drinking the surface water without treatment can be treacherous because of Giardia, and there are warnings about how much fish you can eat due to an ugly legacy of gold mining up in the mountains.

Our wastewater treatment outflow is very clean. Some municipalities treat stormwater and some don't. (There are occasional leaks and some plants only treat to secondary plus, but our track record is pretty good.)

(I'm not trying to challenge, I'm trying to learn. Americans are totally paranoid of the water in other places (and for good reason, as I learned in Mexico last month), and it's interesting to me that other people would find the water in the US scary.)

[TheMadMonk]

37. non-potable Not considered suitable for drinking or cooking.

Probably better quality than surface water in general.

Specific quality in the US I couldn't speak to, except that I know quality standards are not real uniform.

[Confusious]

41. I watched some talk about using all the available resource

to maximize efficiency. I make it sound worse then it was, due to lack of words. As an example, having solar cells in a hot area and grow food plants underneath. The cells create electricity, and the plants get shade, where they would normally cook from the sun.

Unfortunately, American cities are designed by committee and have a hands off approach to that sort of stuff, even when it would benefit us.

They say foresight is the defining characteristic of humans. I sometimes wonder how many Americans are human.

[XemaSab]

47. Don't assume plants are like humans

Desert plants don't "feel better" with more water and shade.

[Confusious]

48. I was talking about plants that can't handle the sun

like desert plants. corn, wheat, etc....

[txlibdem]

38. I like your heat storage idea

While I don't understand how it would tie in with photovoltaic panels, I think you are onto something. I could see it working well with solar thermal to store heat (or cold) in a heat store like a gravel pit. I've also heard of a sand pit with a closed loop of pipes from the energy source, and another closed loop of pipe that go to the inside of the house to take the heat from the sand (or to dump the heat from the inside).

I would suppose that in the summer the energy source would be underground pipes since the temperature at 4ft or 6ft depth is always around 50 or 60 degrees depending on your latitude, or (if you're lucky enough to be near water) a lake, pond, or river. And in the winter the energy source would be a solar hot water unit that you could build for probably less than $100 if you're even a little bit handy.

[TheMadMonk]

42. PV --> Heat pumps. Run them backwards for electricity out.

Or utilise the heat energy directly for neighbourhood heating and cooling.

Solar thermal too would drive the heat pumps rather than attempt to dump heat straight into the store.

[donco]

15. Install them on the steps of parliament. nt

[txlibdem]

17. Install them on the rooftops of every building in London

Why not?

[jpak]

18. Yawn - wind power is economically viable and produces significant amounts of electricity in the UK

the end

[arachadillo]

29. Wind Power in the UK

In general it tends to be assumed that a wind farm will generate an average of 30 per cent of its maximum capacity over time. However the new study shows that this is actually untrue, with the turbines measured by the Grid turning in performances which were significantly worse:
Average output from wind was 27.18% of metered capacity in 2009, 21.14% in 2010, and 24.08% between November 2008 and December 2010 inclusive.

The Points: Mostly Methodological

kristopher: No study is perfect and this one was done using easy to access data that may or may not be representative of the actual state of the wind output actually delivered. It is a good study for what it is, though. It is normal to use data like that when doing a first cut investigation of an issue. If results like this are reported those results need to be looked at more closely by people with more expertise and resources to see if 1) there is a problem, then 2) accurately define where the problem lies.

Next point also involves the data sample - they don't have data on about half of the installed wind feeding into the grid. That seems particularly problematic to their conclusions regarding both the average capacity factors achieved and the overall availability of wind as part of the grid. They used wind turbines that are direct connect to the grid - ones that the grid can "see" as they put it, "If a wind farm connects to a substation owned or operated by NG, NG can “see” it. If it simply hooks into the wider distribution system, NG cannot “see” it."

txlibdem: NG can “see” around 50% of all industrial UK wind generation. There is no reason to believe that wind generation not “seen” by NG performs any more efficiently. Indeed, it is possible that, since all the onshore wind generation in the metered total is presently in Scotland, which is generally windier than the rest of the UK, the “unseen” wind generation may perform less well.
Until July 2010, all wind generation “visible” to NG, and in the data analysed in this Report, was from onshore wind in Scotland. It represented about 80% of all industrial wind generation in Scotland and had a good geographical spread. It is reasonable to assume, due to the good geographical spread, that the “visible” generation was a fair representation of all generation in Scotland at that time.

kristopher: The common factor of the included group is, as far as I understand, something that would be found in small scale projects that do not aggregate the output of a large number of units before shipping the power to the grid. Therefore the projects are probably small scale, lower budget and on the lower end of the productivity range.
The common factor for the other group is that they DO channel their output into a substation that is owned and operated by the wind farm operator where the power is aggregated into a smoothed product that can integrate directly into the grid. This represents a substantial investment and would mark the turbines in this set as being (probably) larger scale, with higher budgets and on the higher end of the productivity scale.

It could very well be that the statistics reinforce what experts already tell us. Onshore wind conditions, and therefore the power they are capable of producing, are less reliable than offshore wind.

The study methodology tells us that five months of offshore wind were added to the statistics. "After July 2010, with output from offshore wind farms off North East England, in the Solway Firth and at Thanet off the Kent coast having been added to those “visible”, the geographical spread became dispersed, and the data is no longer representative of any particular area."

Without looking at the stats, it's my understanding that those offshore wind farms are a small part of the total U.K. wind generation capacity. So, their inclusion may not do much for the statistics, one way or another.
It's the large North Sea offshore wind projects (east coast) that may or may not make a difference in overall wind generation capacity.

In any event, using an estimate of 25% generation capacity, rather than the 30% might be a better way to organize electricity planning.

Over promising and under delivering appears to be a rule of thumb in the energy sector, whether it's renewables, nuclear (their costs always come in two to three times higher than they originally promise) or "security related" wars for oil in the Middle-East. Remember the time we were promised that Iraqi oil revenues would pay for a $2 trillion dollar war?

[XemaSab]

30. The problem with "planning" for 25%

is that you actually have to plan for 0% *AND* 50% at the same time.

Coal and nuclear plants cannot be turned on and off easily depending on whether a particular day is windy or still, so natural gas and hydro must be used to make up for the still days when there is no wind. This means that for every wind farm, you have to build another peaker facility somewhere to make up that energy when there's no wind feeding into the grid.

The report does discuss how much of this is currently buffered using pumped hydro schemes, and the results are bad.

Because I am personally opposed to building more reservoirs and more gas plants, I don't think we should build more wind farms.

[arachadillo]

40. Wind Power Math

Thanks all for the responses, let's see if I can make some types of general, summary sense....

Most experts adopt an electricity maximization approach when trying to incorporate large scale wind electricity generation into long term total electricity generation scenarios. The problem, however, is that wind energy generation is highly variable and not suitable to storage (as might be the case with solar and molten salt storage).

The issue with wind power in the UK might be high variability in average wind speeds, or insufficient data (three years of partial wind energy production), or a combination of both factors.

XemaSab says: The problem with "planning" for 25% is that you actually have to plan for 0% *AND* 50% at the same time.

Coal and nuclear plants cannot be turned on and off easily depending on whether a particular day is windy or still, so natural gas and hydro must be used to make up for the still days when there is no wind. This means that for every wind farm, you have to build another peaker facility somewhere to make up that energy when there's no wind feeding into the grid.

That makes sense to me...

txlibdem says: These show that Scotland has far and away the best winds in the UK. Also mentioned earlier is the fact that the UK has about 1GW in wind power and has 2.7GW in pumped hydro storage with a 5 hour store, about 1.6GW of that can last another 17 hours, for a total of 22 hours of storage. This is an excellent model for the US although I'd like to see an 8 hour store for peak energy times and a "base" storage of 24 hours.

At issue is finding a 24 hr "base" storage medium. Far as I can tell, only the Pacific NW has sufficient hydro to even attempt to reach that goal. What can TX do for storage when its wind farms are taking a time out?

as an aside, sorry about the quoting out of context, I do not refute Uk wind energy potential numbers, I'm just suggesting that I do lean to thinking of onshore wind potential as highly variable. Maybe three years of statistics is insufficient for use in that study. Maybe three years from now, the numbers would look a bit different, (i.e., longer term data helps smooth out bumps in short term statistical analysis...after all, NOAA keeps average wind speed caclulations for major cities based on long term statistics
http://www1.ncdc.noaa.gov/pub/data/ccd-data/CCD-2009.pdf (put page 66 in the search to retrieve the long term average wind speeds)

also, I just returned from a trip to your wonderful state. Boy is it windy in March along the LRGV:)

PamW says, One of the problems with wind power is a result of plain basic physics. That is that
the power of a wind turbine goes as the cube of the wind speed.

If the wind turbine sees wind that is 50% of its maximum rated wind velocity, then it should produce 50% of the power that it would at that velocity. Right? WRONG!

It will produce 1/8-th the power. If your wind turbine is rated at 800 kilowatts in a maximum 50 mph wind, then at a 25 mph wind, it will produce 100 kilowatts, not 400 kw.

I've been trying to read many of the technical specifications from manufacturers regarding average annual wind speeds and electricity generation potential. The curved graphs they present for their electricity generation potentials verify your presentation.

[kristopher]

49. Your summary is flawed in several places. This might help.

Wind Power Myths Debunked
Common Questions and Misconceptions

Introduction:
THE RAPID GROWTH OF WIND POWER IN THE UNITED STATES AND worldwide has resulted in increasing media attention to — and public awareness of — wind generation technology. Several misunderstandings and myths have arisen due to the characteristics of wind generation, particularly because wind-energy generation only occurs when the wind is blowing. Wind power is therefore not dispatchable like conventional energy sources and delivers a variable level of power depending on the wind speed. Wind is primarily an energy resource and not a capacity resource. Its primary value is to offset fuel consumption and the resulting emissions, including carbon. Only a relatively small fraction of wind energy is typically delivered during peak and high-risk time periods; therefore, wind generators have limited capacity value. This leads to concerns about the impacts of wind power on maintaining reliability and the balance between load and generation.

This article presents answers to commonly asked questions concerning wind power.
It begins by addressing the variability of wind and then discusses whether wind has capacity credit. The article addresses whether wind can stop blowing everywhere at once, the uncertainty of predicting wind generation, whether it is expensive to integrate wind power, the need for new transmission, and whether wind generation requires backup generation or dedicated energy storage. Finally, we discuss whether there is sufficient system flexibility to incorporate wind generation, whether coal is better than wind because coal has greater capacity factors, and whether there is a limit to how much wind power can be incorporated into the grid...

Summary
The natural variability of wind power makes it different from other generating technologies, which can give rise to questions about how wind power can be integrated into the grid successfully. This article aims to answer several important questions that can be raised with regard to wind power. Although wind is a variable resource, grid operators have experience with managing variability that comes from handling the variability of load. As a result, in many instances the power system is equipped to handle variability. Wind power is not expensive to integrate, nor does it require dedicated backup generation or storage. Developments in tools such as wind forecasting also aid in integrating wind power. Integrating wind can be aided by enlarging balancing areas and moving to subhourly sched- uling, which enable grid operators to access a deeper stack of generating resources and take advantage of the smooth- ing of wind output due to geographic diversity. Continued improvements in new conventional-generation technolo- gies and the emergence of demand response, smart grids, and new technologies such as plug-in hybrids will also help with wind integration.

Download this open access article free (normally this journal's articles are priced at $26 each) : http://www.ieee-pes.org/images/pdf/open-access-milligan.pdf

This source of information is as credible as can be found on these frequently misrepresented issues related to wind power.

[arachadillo]

51. Read the Article

I see we're still talking about wind. Great. I read the article, although I do not see how it relates to a flawed analysis on my part.

If you build and use wind plants, there is variability in the electricity generating output, from not enough wind, to too much wind (as when farms need to be shut down), to variable amounts of wind that fit between those extremes.

If electricity providers prioritize wind generated electricity, using all that is available at any given time, (and if the grid could be improved to use all of the available wind generated energy), it sounds as if the article suggests that, assuming the aggregate amount of electricity demand at any give time is being met, then the generated wind energy will replace some other type of energy (probably coal or nuke) that was previously used to meet that demand.

At face value, I find nothing wrong with that.

OTOH, I assume that the shareholders of the coal and possible nuke plants, whose electricity generation potential are reduced by being replaced by the wind will be upset.

My initial response to them would be tough noogies, but I'm sure they would not appreciate that.

So, I'm not actually anti-wind, it's just that I'm more concerned with removing the coal and nuke plants from the electricity generation equation, and I do not see how wind does that. It looks as if wind energy generation just creates conflicts with already existing coal and nuke plants that also want to maximize their generation capacities.

Am I missing something?

[Yo_Mama]

52. No

The problem with wind is that it does little to displace base generation capacity.

Wind is an acutely variable source of power. Grid demands are also pretty variable - generally at least 40%.

So now you have an acutely variable source which phases differently from considerably variable demand.

Suppose you install a huge array of wind turbines in good wind territory and they are in good repair. The wind variance (see Pam's post) is such that installing an average capacity rated output sufficient for 100% average grid demand could net you 5% or 10% grid demand at any one time, but will also sometimes give you 200% grid demand. What do you do with it?

So the more wind turbines you install past a certain percent, the less of the generated power you actually use. The only way to get around that is to divert wind-generated electricity to something like pumped storage, so you can cycle those turbines on to cover actual grid demand.

That's very expensive, but it also lowers your actual net output to grid, because you are generally adding transmission losses and then of course there is the loss of power involved with converting one form of energy to another.
http://en.wikipedia.org/wiki/Pumped_storage_hydroelectricity

But it does allow you to supplant other forms of energy generation, which is what you need to do to use wind power to supply grid power. This is why every place that has tried it has seen diminishing net usage factors. It's the nature of the beast.

Wind doesn't scale up well, and it never will. It becomes more and more expensive once you try to escape the natural 6/8% limit, and the more you install, the more expensive it is going to get.

[txlibdem]

50. Hope you enjoyed your visit to Texas!

PS, it's windy just about everywhere in TX in March and April. Yesterday we had gusting winds to 60 mph here in dallas and steady winds of 25 to 35 depending on which part of the metroplex you're in but that was a storm system moving through so the wind gusts were way higher than I've seen during the past month. We've been hitting 20 mph to 35 mph winds at least half the time here. Today? The weather lady said 5 to 10 mph winds today (as I write this it is 1 mph per weather.com).

To answer your question about Texas storing all that wind power? Nothing that I am aware of. In March 2009 they had to shut down the wind turbines because it exceeded the capacity of the power lines connecting them to the grid (they were outputting 23% capacity).

[txlibdem]

39. Good summary, and welcome to DU!

:applause:

I had a tiny, tiny beef with the way you quoted the last statement from a poster that has no basis in fact and no reference to where they came to that opinion... but why quibble.

Instead of repeating what I already said in post #7 above:
From post #7, offshore and onshore wind maps of Europe
-----------------------------------------------------------------
The UK does seem to have the best offshore wind potential in Western Europe. Here is a map of offshore winds, showing wind speeds at 5 different elevations:
http://www.windatlas.dk/europe/oceanmap.html

Onshore wind is also a great resource that Britain should be taking full advantage of:
http://www.geni.org/globalenergy/library/renewable-energy-resources/world/europe/wind-europe/index.shtml
... you have to scroll down about 2/3rds of the page to see the Wind Map of Western Europe. It shows that the entire coast of Ireland, all of Scotland, the coasts of Norway, Sweden, and Finland are very well suited for wind farms (have the highest wind speeds).
------------------------------------------------------------------

These show that Scotland has far and away the best winds in the UK. Also mentioned earlier is the fact that the UK has about 1GW in wind power and has 2.7GW in pumped hydro storage with a 5 hour store, about 1.6GW of that can last another 17 hours, for a total of 22 hours of storage. This is an excellent model for the US although I'd like to see an 8 hour store for peak energy times and a "base" storage of 24 hours.

Regarding offshore wind resources in Western Europe, a recent OP in EE referred to an offshore wind farm in Denmark that has achieved the highest average output of any wind farm. If you look at the offshore wind map above (bring up google maps if you need to find Denmark) you will see that that offshore area of Denmark has the same wind speeds as the UK's North Sea. This tells me two things: 1) the UK should tap this excellent resource, and 2) that area has some of the roughest seas anywhere and that will be both a challenge for offshore wind farms but also a great resource in the form of wave power that is currently just going to waste.

[PamW]

31. Not surprising - it is to be expected.

In general, then, one should assume that a wind farm will generate no more than 25 per cent of maximum capacity over time
================================

One of the problems with wind power is a result of plain basic physics. That is that
the power of a wind turbine goes as the cube of the wind speed.

If the wind turbine sees wind that is 50% of its maximum rated wind velocity, then
it should produce 50% of the power that it would at that velocity. Right? WRONG!

It will produce 1/8-th the power. If your wind turbine is rated at 800 kilowatts in
a maximum 50 mph wind, then at a 25 mph wind, it will produce 100 kilowatts, not 400 kw.

With a halving of the wind speed, you have half as much air flowing through the turbine.
However, the kinetic energy of the air goes as the square of its velocity.

So with a 50% drop in wind, you have 1/2 the wind, but that wind has 1/4 the energy per
unit mass, and hence the combined effect is 1/8-th the output.

PamW

[XemaSab]

34. ONOZ!

Teh math! :o

[jpak]

43. What are the current capacity factors of Fukushima-Daiichi units 1, 2, 3 & 4 ?

and TMI Unit 2?

and Maine Yankee?

:shrug:

[XemaSab]

44. What's the capacity factor of Altamont?

:shrug:

[jpak]

45. Greater than zero - which is more than the collective capacity factors of those nukes

yup

[jpak]

46. Nuclear power not doing so well in Japan

yup