Wind Integration: An Introduction to the State of the Art

Posted on August 02, 2007
Posted By: Sandy Smith
Topic: Wind
 
Over the past few years, wind power has emerged as a significant generation source of electricity. According to the American Wind Energy Association (AWEA), in the United States alone, during 2006, 2,454 megawatts (MW) in nameplate capacity was installed, bringing total capacity to 11,603 MW. The U.S. Department of Energy (DOE), in a report on wind power, noted that the U.S. represents roughly 16 percent of the worldwide wind market, followed by Germany, India, Spain, and China. AWEA and DOE are working to finalize a 20 percent by 2030 Vision Scenario for Wind, with a formal introduction to the industry later this year.

Wind power, now recognized as a utility-scale energy source, represents unique challenges for the industry in terms of system planning and operation. A significant challenge is how to address the variable nature of wind – it does not blow at the same speed all of the time. This drives concerns about changes in the operating costs of the nonwind portion of the generation mix, as well as overall electric system reliability. For a number of years, the Utility Wind Integration Group (UWIG) has conducted research and coordinated with electric utilities, research organizations, and government and industry groups to quantify these impacts and examine practices, technologies, and mechanisms to manage or mitigate them.

There have been a number of studies that have examined the implications of various wind penetration scenarios. A 2006 study conducted for the Minnesota Public Utilities Commission evaluated and quantified reliability, operating and market impacts of three levels of wind generation: 15, 20 and 25 percent of Minnesota retail sales in 2020. The study found that the total integration cost for up to 25 percent wind energy delivered to Minnesota customers is less than $4.50 per MWh of wind generation. It should be noted that the 25 percent penetration level of wind is predicated on operating in the Midwest Independent System Operator (MISO) market, control area consolidation in Minnesota, geographic diversity of the wind power and adequate transmission.

Penetration levels of this extent are already being seen in Europe, where wind provides more than 20 percent of the electric supply in Denmark as well as portions of Germany and Spain. Although penetration levels in the United States are nowhere near those levels – less than 1 percent of total energy generated and less than 10 percent for some individual utilities – a number of states – California, New Mexico, and most recently Minnesota, Oregon, and Colorado – have or are implementing Renewable Portfolio Standards of 20 percent or more where wind will play a significant part in the electricity supply scenario.

Responding to Industry Requests

UWIG was asked by the Power Engineering Society of the Institute of Electrical and Electronics Engineers (IEEE) to assist in putting together an issue of its Power & Energy Magazine focusing on integrating wind into electric utility systems. That issue (November/December 2005) became widely accepted as a reference document on the subject. UWIG is now working with the IEEE Power Engineering Society on an update of the issue, which will be released this November.

In early 2006, drawing from the articles in the November/December 2005 issue of Power & Energy Magazine, UWIG developed a summary of the findings published in the 2005 issue and repackaged it into a document available on the UWIG web site (www.uwig.org). The document was prepared by UWIG in coordination with the Edison Electric Institute, American Public Power Association, and National Rural Electric Cooperative Association. The summary document noted that wind generation can have impacts on the power system, but can be managed through proper plant interconnection, integration measures, transmission planning, and system and market operations. The document noted that in regards to the integration cost associated with up to 20 percent wind capacity penetration, system operating cost increases arising from wind variability and uncertainty amounted to less than 10 percent of the wholesale cost of the energy produced by wind. The costs can be managed through a variety of means – most notably accurate wind forecasting. And it should be noted that the costs should be viewed in light of wind replacing reliance on fossil generation, where fuel price risk and carbon risk are of increasing concern.

The compatibility of wind plant operation with the electric power system has always been a significant question. The UWIG document noted that wind plant terminal behavior is different than that of conventional power plants, but can be compatible with existing power plants through the use of sound engineering practices and technology. The document states that “with current technology, wind power plants can be designed to meet industry expectations such as riding through a three-phase fault, supplying reactive power to the system, controlling terminal voltage, and participating in SCADA system operation.” It should be noted that the Federal Energy Regulatory Commission (FERC) codified these parameters into Order 661-A, Interconnection for Wind Energy. This rule constitutes a "Grid Code" for large generators with a capacity of 20 MW and above.

Wind is not a Capacity Resource

In terms of integrating wind, a common assumption made about wind power is that it requires an equivalent amount of backup generation to mitigate its variability. Wind is an energy resource – as opposed to capacity resource – and does not require backup generation provided that wind capacity is properly discounted in the determination of overall generation capacity adequacy. Significant levels of wind penetration will impact overall generation mix and dispatch as nonwind generation is needed to maintain system reliability when winds are low or not blowing. There is a real need to understand and properly treat the capacity value of wind plants within the overall system. The capacity value of wind generation is typically 10 to 40 percent of its nameplate rating and depends heavily on the correlation between the system load profile and wind plant output. Effective integration of wind generation can be ensured through good wind forecasting capability, implementing plant output forecasting in both power market operation and operations planning, adequate system flexibility, adequate transmission, and well-functioning markets.

In terms of transmission planning and market operation, a lot of work has been conducted to examine and evaluate wind development scenarios and how to accommodate more wind generation. In terms of transmission, significant efforts have been underway in the Western United States with the Western Governors’ Clean and Diversified Energy Action Plan and in Texas with the creation of Competitive Renewable Energy Zones (CREZ). These are primarily focusing on addressing one corollary about wind – it tends to blow best where transmission is not readily available. Work has also been underway to better understand and manage the interplay between transmission system tariffs and wind. There have been generator imbalance penalties in place for generator output schedule deviations through FERC Order 888, which led to a drive to remove the penalty-based imbalance tariff and replace it with a cost-based imbalance tariff. This will remove the barriers to wind plant development in large regions of the country. This was recently accomplished through FERC Order 890, which moves most wind generation imbalance to a cost-based payment, and addresses several other issues of importance to wind, including a flexible-firm transmission tariff, redispatch, and regional transmission planning.

In addition to building more transmission and properly treating wind power in terms of system operations, the development and expansion of well-functioning day-ahead and real time markets will provide an effective means of dealing with the variability of wind generation. There is also recognition that consolidation of balancing, or control, areas can assist in the management of variability, as can the aggregation of broadly geographically dispersed wind plants.

The Utility Wind Integration Group, as well as followers of the wind and electric power industries, has noted that there is a continuing need to expand the understanding and quantification of the impacts of wind generation on utility power systems. A critical facet of this is effective modeling of wind plant output and behavior and improvement in the quality and utilization of wind forecasting. Advances in wind turbine technology, as well as plant design and operation procedures, will also facilitate effective integration of wind. On top of all this is the need to expand and enhance the nation’s transmission infrastructure and optimize market design and operation to address wind’s variability. Since its beginning, UWIG has recognized that the key to making this all work is through an improved understanding of how increasing amounts of wind capacity affect the system, increased dialogue and information exchange. UWIG remains committed, through its mission of facilitating the responsible integration of wind energy into electric power systems, to keeping the electric power industry informed about the state of the art in wind integration. Stay tuned.

 
 
Authored By:
Sandy Smith is Communications Coordinator for the Utility Wind Integration Group, an organization working to facilitate the responsible integration of wind generation into utility power systems. UWIG’s membership is comprised of utilities, ISO/TSOs, equipment manufacturers, wind developers, and government and research organizations. Additional information on UWIG can be found on the Web at www.uwig.org. Sandy also serves as a consultant in market and technology analysis for EnerNex Corporation. He was
 

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Comments

August, 02 2007

Len Gould says

"Effective integration of wind generation can be ensured through good wind forecasting capability, implementing plant output forecasting in both power market operation and operations planning, adequate system flexibility, adequate transmission, and well-functioning markets. "

Agreed, though I think the markets point is most important and deserves emphasis, especially "well-functioning markets WHICH CLEARLY EXPOSE END CUSTOMERS TO REAL_TIME PRICES". Personally, I would also add "and encouraging automobile users to demand and use PHEV vehicles".

August, 02 2007

Malcolm Rawlingson says

Here we go again. Nameplate values (once again quoted here as if they have any significane whatsoever) are meaningless. Wind proponents appear to think that is all that matters.

I note that the author does admit that the capacity value (Capacity Factor?) for wind is a mere 10 to 40%. Nothing else but solar power comes close to that abysmal level of performance.

No mention is made of the harmonic instability problems associated with the installation of large numbers of these facilities into grids. Neither is ther any mention of the limits that most grid operators are applying to limit these effects to prevent blackouts. The Alberta (Canada) system operator is limiting wind generation to no more than 10% of capacity (that IS nameplate capacity).

Most gid operators are having wind generators forced on them by political decisions not by good engineering or economics and we are going to pay a hefty price for their stupidity. Landscapes and seascapes destroyed, bird habitats wrecked and all for a measly 20% average capacity factor and most of the time generating when the grid does not need it and not generating when the grid does need it.

Wind energy is a waste of time as any sane person will attest.

Malcolm

August, 03 2007

Todd McKissick says

Excellent article. Very informative on the work being done to address and standardize the various issues with wind. Much more than I had expected. I actually come away wondering if they're planning too much for wind now because the game may significantly change when large amounts of solar (PV or thermal) is integrated into the mix. As is repeatedly mentioned around here, "those hot summer days are when we need more power and the wind track record is low then" Wind and solar could end up complimenting each other better than expected which, combined with PHEV inevitability, will change all the work done now to support wind alone.

Malcolm, "After midnight tonight, you will be visited by three spirits...." Maybe one will read you the rest of the article.

August, 06 2007

Edward Reid, Jr. says

Todd,

I believe it is fair to say that Malcolm has already been visited by the "Spirit of Wind Past" and the "Spirit of Wind Present"; the script for the visit by the "Spirit of Wind Yet To Come" is still being written, and the visit has not yet been scheduled.

Ed Reid

August, 06 2007

Malcolm Rawlingson says

Some sobering wind facts versus wind fiction.

You were right Todd!!!! The Spirit of wind visited me last Thursday. but it was in a bad mood.

Here is what the spirit said.

Last Thursday was one of the largest electricity demand days in Ontario Canada of the year - it was very hot - 33 to 35 degrees centigrade with high levels of humidity across most of the Province. Quite typical of this part of the world in the summer time. It is what makes it such a great place to live. A bit sticky but one can retreat into an air conditioned building or house if you need to cool off a bit.

The wind spirit directed me to the IESO (Independent Electricicty System Operator) website. Once there it told me - with great bluster and huffing and puffing with pride - that Ontario has an installed wind capacity...(and so there is no mistaking it - that is the sum of the NAMEPLATE RATINGS of all wind generators installed in the Province of Ontario) ....of 400 Megawatts. YES we have FOUR HUNDRED MEGAWATTS OF WIND GENERATION IN THE PROVINCE and growing. (I can hear you all cheering and see you all throwing your baseball caps in the air with glee)

But sadly the spirit of the wind was having a very lazy day last Thursday. During the peak hours of demand and for most of the day in Ontario the sum total of ALL of the wind generators in the Province was 4 Megawatts

Yes, you read the number correctly..... that is FOUR MEGAWATTS - FOUR WITHOUT A ZERO MEGAWATTS from 400 MW installed....a 1% capacity factor. I asked the spirit of the wind why it was not blowing on all of the wind generators in Ontario to help us shut down all the nasty fossil plants when it was so hot and all it said was "you can't control me" and blew away.

So for all you sad individuals who think this is the way to operate an industrial economy I did the following bit of arithmetic. If wind generation had a nameplate installed capacity of 10% or about 3200 megawatts we would have received a gigantic contribution from wind on the hottest day of the year in Ontario of just 32 megawatts. System line losses account for more than that.

Let me assure each and every one of you that wind WAS being backed up by fossil fuelled plants in the USA and CANADA. If we were to have relied on wind to do the job I do assure you the lights WOULD have gone out. The air conditioners WOULD have gone off and factories WOULD have been shutdown and the Province WOULD have had blackouts....all on the hottest day of the year.

Now do you people REALLY want to rely on this energy source for your prosperity. Good luck to you if you do. It doesn't work - it never has and it never will simply because you have no control over the source of energy.

So since the spirit of the wind has departed and reality has set in please don't tell me that wind will be anything more than a highly subsidised uneconomic fringe player. If you cannot control the fuel when you have the demand then it is a complete waste of time and money. And not even you folks can control the spirit of the wind.

I am sure that once the astute politicians (the few who are left) realize that what they have been fed is complete codswallop we will see these edifices as monuments to an era of human stupidity that they really are.

I'll bet my money and prosperity on the spirit of the atom thankyou.

Just for the record my plant was running flat out at 100% capacity during the entire period as it has for months now. For those who still don't get it 100% capacity factor means the nameplate rating equals the power going out. Nuclear did that, fossil did that - wind sadly did not because it could not deliver.

I am now certain through all the nonsense I have read on wind that the ONLY thing that will convince you is that the lights DO go out when the wind does not blow and there is nothing left to support it. That time is fast approaching so better buy a diesel generator.

Malcolm....on another hot and windless day in Ontario.

August, 06 2007

Todd McKissick says

Malcolm, Wow. More than a dozen paragraphs to repeat "those hot summer days are when we need more power and the wind track record is low"? We all know that. By recommending that you read the rest of the article, I was addressing the article's information on mitigating that. Everybody knows the risk of there being no wind on a given site, but at issue is the savings associated with whatever you do get from this resource. Some value the CO2 not created while others value more the reduced mining operations associated or the nuclear fuel saved for later generations. I personally value the savings in massive transmission systems and the distributed nature of failures. (What was the Japanese nuclear plant's capacity factor last Thursday? Better yet, how many MW was that region shorted below 'planned for' capacity?) Even if nuclear power was as low as the $4.50 / MWh quoted in the article, would the utilities ever drop the retail price down to that?

The point is that with the techniques mentioned in the good Mr. Smith's article, this resource, and many others, can contribute towards the end goal. That goal is to get all our energy from truly renewable and truly green sources. Today's nuclear advocates sound like the oil promoters did one lousy century ago: "Oil is unlimited so why bother with anything else?" That statement is no less simple minded then as it is now.

As I see it, your only argument that holds any water is cost. Even though I'm not 100% convinced that nuclear is cheap now, I am convinced that there are many alternatives that will be much cheaper in the near future. I've seen proposals that offer net surplus energy homes or businesses for less than a 10 year payoff period.

The energy 'experts' keep asking where they are, but they don't realize that this new generation (pun intended) isn't being supported by some Manhattan Project. It's a thousand small groups, each with their own funding issues. The way our illustrious grant system works, most don't even qualify for any grants! So it's taken half a decade so far, but they have begun to show up all over. I'm guessing the spirit of wind future and all her buddies will show up pretty soon.

August, 07 2007

Norman Lee says

The "spirit of the future" is constantly changing its story. But this much I know. The nuclesr 100% you are quoting has many drawbacks of its own. Not even looking at the environmental issues of nuclear, there is a problem with the 100% capacity factor. The problem is that it is 100%. Nuclear plants can not be backed down or cycled to meet load requirements hour by hour. You still have to have other types of generators to fill in the gaps. I feel that in the end, we will have a wide diverse portfolio of generators to meet all of our enegy needs. This will allow us to meet our needs in an economic, secure and reliable manner.

August, 07 2007

David Dixon says

"Wind is an energy resource – as opposed to capacity resource" - some thing all of the Spirits can agree upon.

I read so many press releases from the wind industry announcing a new project will produce 'enough electricity for XX homes'. If wind is not a capacity resource it cannot meet the needs of any homes. I hope furure press releases will drop that tag line and/or that the readers of Energy Central will write letters to the editors who repeat that erronious statement. And when local governments mandate 10% or 15% or 20% renewable power, do they understand that wind is an energy resource, not a capacity resource. Is this what they intend the mandates to produce, no incremental capacity?

August, 07 2007

Ramon Mischkot says

Very well written and informative article and good follow-on discussion. With regard to the economics of wind and other renewable technolgogies I want to add the following. Their economics--and by that I mean $/MWh--improves substantially if depreciated over their full potential operating life. Because fuel is virtually free and O&M relatively low, the main cost is the rate at which capital investment is depreciated. The current practice is to depreciate wind turbines over 20 or 25 years. I believe the life of wind turbines can be at least twice that; 40 to 50 years. The key is the life of the tower. I have been told by engineers who have analyzed towers that they have a life comparable to other structural components--well over 50 years. On the other hand, others (maintenance people) have told me 20 years is more accurate. I would like to solicit comments from the author and others commenting on their beliefs in this regard and the basis for such beliefs. Thanks.

August, 07 2007

Ferdinand E. Banks says

I'm with you Malcolm. The evidence from Denmark and Germany makes it clear to me that wind is a sub-optimal option - at least at the present time. And let me repeat for the Xth time, if wind could do all that its advocates claim, Sweden would be one of the most wind intensive countries in the world. The bottom line in this matter however was well expressed by Norman Lee "...in the end we will have a wide diverse portfolio of geneators to meet all of our energy needs." Wind will be present, but not to the extent that its proponents desire.

At the same time I recognize that where things like nuclear and wind are concerned, evidence doesn't mean much to the movers and shakers.

August, 07 2007

Malcolm Rawlingson says

I did indeed read the rest of the article. Integration with PV cells (read double or more capital cost) - give me a break. You would have half of the most valuabl;e farmland covered in PV arrays.

Todd......if it really worked we wouild already be doing it. it does not. The energy sources are not controllable and are too diverse.

As far as cost .... mass production doesn't just work for cars. Start mass producing nuclear plants and you will see the costs plummet.

Suggest you read the book "The Solar Energy Fraud" to see the physics of why wind and solar will not work and why you and many others are being hoodwinked.

Will provide references later.

Malcolm

August, 07 2007

Jim Beyer says

Wind's problematic nature, especially on hot muggy days, is well-known. Thanks to Malcolm, this can be shown is fairly stark terms.

The lowest cost renewable solar source is Solar thermal. (Think of a bunch of mirrors pointing at a Stirling Engine or some such thing.) This is much less expensive than PV, and even less expensive than wind. 5-6 cents per kW-hr.

Would probably complement wind to some extent.

If/when we decide to go down the path to eliminate coal (which we seemed compelled to do for the sake of the planet) then this is a tough situation, indeed. With or without nuclear power.

A few years ago, Panda energy was going to build a NG-fired plant nearby. They didn't build it, but it was pretty clear all they needed to do was get some land, get the grid connections, and off they go. I suppose a coal-fired plant is a bit more complicated, but probably not much more so. Compare this to a nuclear power plant. A much bigger deal. They are as big as they are because no one would waste the hassle on a small plant. I'm not trying to be critical, just practical. We can no easier build nuclear plants by the dozen than we can command wind to blow when we want it. Perhaps tragic or inane, but nontheless true.

August, 08 2007

Malcolm Rawlingson says

I agree there is no easy solution to building any plant or any grid connection. The public - and that includes me - would for sure like to look at farmland and countryside than any power line or power producing facility. I can't say a really want to see a nuclear power plant in my back yard (although mine is not that far away from me).

But properly planned and with the very high power density and miniscule environmental impacts from their operation I would rather have a nuclear plant than ten thousand windmills or square miles of farmland covered with PV cells with weeds growing in between that don't work half the time.

Once you have the political will (as was and still is the case in France) it is indeed quite possible to build nuclear plants by the dozen. It is the continual "yes we will - no we won't" start stop policies prevalent in North America that prevent the mass production approach necessary to achieve the dramatic cost reductions that are possible. With a properly organised and planned approach I believe that current construction costs could be halved by mass producing components and standardised designs.

Wind and solar proponents need a reality check when it comes to the amount of power these sources are really able to produce - and of course why I get so annoyed at the continued use of "nameplate ratings" whose only purpose is to fool those who do not understand - mostly politicians.

Of course I have maintained all along that, with the appropriate low cost storage wind and solar could play a role in large scale generation but when you add in all the costs of doing that it's uneconomic.

Todd is quite correct in that nuclear power did benefit from much basic research done for the Manhattan Project. As every miner knows - dynamite was invented for military purposes but sure has found practical peaeful uses. Would we consider NOT using dynamite, nitroglycerine or any other explosive developed for military use simply because it has a military use? Much of our GPS technology was military in origin. The internet that we are using now had its roots in military research so to say we should not find a peaceful use for a technology that had its roots in military projects is rather foolhardy.

If that is so all you Hummer drivers out there need to turn in your vehicles now.

I am not against the use of wind or solar or any form of energy - I am very much against claims that it can be more than it actually is.

Tidal energy may be practically a better method than wind since the tides and wave motion are fairly steady...much less variable than wind. But we will see what that technology can bring to the table.

Wind and solar cannot bring that much unfortunantely.

Malcolm

August, 09 2007

Kenneth Kok says

Just to show the variability of wind here in Eastern Tennessee, llok at some real numbers from TVA. The wind generating facility on Buffalo Mountain just outside of Oak Ridge has a nameplate capacity of 29 MW. Over an earlier 30 month period TVA stated the system had generated 133 million kwh which is 21% of the nameplate capacity. A quick check of the TVA data for April - June of 2007 shows the generation of 490,256 kwh for the period or 0.8% of the name plate capacity.

Ken

August, 09 2007

Dick Maclay says

There is a wide spread assumption that wind generation results in a substantial reduction in green house gas emissions. But the arithmetic supports only a minor reduction. This is because the type of natural gas power plants we will build in the future is different with wind than without.

Without wind we will build combined cycle plants with heat rates around 7000 btu/kWh and declining incrementally with technology. With wind we will build about 95% of the nameplate capacity of gas fired plants we would build without wind. But most will be flexible plants with heat rates in the range of 8500 to 9200 btu/kWh. These areo derivative plants are at least as expensive per installed kW as the combined cycles.

At an average capacity factor of 20% for wind the annual average heat rate with wind is as good as:

20% * 0 btu/kWh + 80% * 8500 btu/kWh = 6800 btu/kWh.

That is a 3% reduction in CO2 emissions compared with current F generation combined cycles without wind. With the H generation combined cycles the CO2 reduction with wind falls to 0% or a little lower.

IF wind can run 30% of the time the % of CO2 savings can reach into the teens. Still unimpressive. Up to some level of penetration combined cycles can help to pick up some of the variation in wind production. If the wind can blow somewhere within reach of transmission at all times things are not as bad as described above. But real world experience shows that areas the size of California, Ontario, and the Pacific Northwest of the U.S. fall below 5% during peaks. The systematic problem is that high electric demand is caused by weather conditions that include little or no wind.

I would love to see wind contribute to a better environment. But it appears that when wind penetrations are high we fall into the problem described above.

August, 09 2007

Edward Reid, Jr. says

Malcolm, Kenneth & Dick,

You all need to put your rose-colored glasses back on and stop being such poops!

Ed

August, 09 2007

Jim Beyer says

NG Power plants make no sense, at least in the US. We don't have enough NG to spare. NG is barely shippable, requiring huge energy costs up front to liquefy it, and the NIMBY factor in building ports in the US to receive it has been pretty strong as well. The last thing we need are NG-fired power plants in the US.

August, 09 2007

Dick Maclay says

Jim, how we go forward depends on our goals. Coal is just fine if CO2 emissions don't matter. Nuclear avoids CO2 for base load power, but some people raise other issues with it. Natural gas is expensive. Wind has no emission of its own, but it does require flexible power plants to fill in the other 70% to 80% of the time it is not running. And it tends to run during off-peak hours, not during on-peak hours. Natural gas fired power plants are the technology we have to fill in around wind. I am just noticing that the amount of natural gas required to fill in around wind is about equal to the amount of natural gas that would be used if we just built the most efficient gas fired plants available. That is probably not really true at low penetrations for wind, but is hard to avoid at high penetrations. 20% of energy from wind is probably a high penetration.

If you don't like natural gas plants you may not like wind, since they seem to come as a pair.

August, 09 2007

Roger Arnold says

Dick brings up a crucial point. Wind energy is intended to displace fossil fuel consumption, not generating capacity, but under a "business as usual" approach to generation it would not even do that very well. That's for precisely the reason that he cites: under a BAU approach, the backing capacity for wind power would be less efficient than baseload power sources. (The same is true, however, for peaking capacity that would go with increased reliance on nuclear.)

That doesn't mean that wind (or nuclear) aren't useful. It just means that we can't follow the simple BAU approach to generation paired with these resources. There are three general strategies available: (1) scheduling of existing dispatchable capacity; (2) increased use of discretionary (curtailable) loads; and (3) energy storage.

Rather than going into any detail here, I'll just point back to the three articles I wrote on "Renewable Energy: Coping with Variability":

Part 1: Supply Management

Part 2: Load Management

Part 3: Energy Storage

August, 09 2007

Jim Beyer says

Well, if cost is no issue (doesn't seem to be...)

then use Wind/Solar to produce grid power and use off-peak generation to synthesize methane. Given about 50-60% efficiency to produce it, that would provide round-trip efficiency of 30-35% when used in a combine-cycle methane plant. Obviously, NG (the fossil fuel) could be purchased as needed as well.

If the technology ever works, eventually move to reversible SOFCs for both methane and electricity production.

But would this really be less desireable than less efficient DG with its CHP? They are about 25% efficient with the electrical production, but with their heat use, overall efficiency can rise to 80-90%.

I guess the only problem I have with Dick's last comment is "Natural Gas is expensive." I think it is more than just expensive. We stand to have greater shortages of that compared even with oil, and I don't hear anyone proposing large-scale oil-fired power plants at this time. I believe most of them were shut down in the 70's. In some ways, NG is even more problematic than oil, because importing it is so difficult to do. EPRI did the same thing in promoting PHEVs by talking about their electrical input coming from combined cycle NG plants. I do think PHEVs make sense, but burning NG (with its lower CO2 emissions) is not the way to do it.

On a brighter note, if we could actually really reduce gasoline use via PHEVs, would that not free up quite a bit of NG now used for gasoline refining? I've heard that NG in the States goes through painful booms and busts, as uses for it rise and fall over time.

I'm not saying Wind Power Variability isn't a problem, but looking to NG to solve it may instead move that problem to another domain.

August, 09 2007

Roger Arnold says

Hmm, while I was composing that last comment, three other new comments came in--including a followup by Dick. I'd like to comment on his statement:
If you don't like natural gas plants you may not like wind, since they seem to come as a pair.
With NG plants, it isn't a question of "like". NG plants are wonderful, in terms of low capital cost, low lead times, and half the CO2 per kWh compared to coal. The problem is the cost and availability of fuel. That situation is not going to get better anytime soon; it will almost certainly get worse.

The nearest alternative is CTs fired by gasified coal or biomass. I expect we'll be seeing a lot more of those. As far as the CT portion of the plant, there's no functional difference between gasified coal or biomass and NG. The trend, BTW, is toward designs that blur the distinction between peaking and baseload units. The newest designs support combined cycle operation at the efficiency of baseload generation, but are robust under cycling. They can therefore be used as dispatchable resources.

August, 10 2007

Dick Maclay says

GE’s LMS 100 can be quite efficient if it is given a combined cycle configuration. Siemens has announced a quick start combined cycle. Up until now, at least, adding the steam cycle has limited the flexibility of CTs. To the degree that flexibility can be retained with improved efficiency it will become possible to reduce gas consumption in conjunction with wind. These units are too new to have established how well they will do in combining efficiency with flexibility. So we shall see how much the problem is being ameliorated. In any case these units will not be cheap. The numbers usually cited for the cost of wind power do not include the capital for the gas fired swing units. But with an RPS, of course, economics don't much matter. Still, the cost of solar is so high today that there would be a consumer revolt if it were employed in meaningful amounts. Perhaps reasonable priced solar will be developed. Hope so. In the meantime...

Wind is more problematic than nuclear because it tends to disappear on-peak and appear off-peak. That makes it an anti-peaking resource. Nuclear is there on-peak as well as off-peak.

I agree that gas is a relatively benign source of energy. But we may not like its price if we rely on it as much as we are heading for. And there may be occasional shortages too.

An important way to improve efficiency is to shift loads from peak to off-peak. Air conditioning with ice storage and plugging in hybrid cars at night would help level the load. Our centrally planned industry has done a poor job of addressing such fundamental issues.

August, 10 2007

Dick Maclay says

Roger, we have looked at the use of hydro to balance wind. The problem we run up against in California is that hydro is already fully committed as a peaking resource. Using it to balance wind would require new CTs to take over the peaking role. The Pacific Northwest has somewhat more flexibility in that regard. Pumped storage is a possibility. That could shift wind. As you have noted, energy storage near loads makes sense.

August, 10 2007

Todd McKissick says

Dick, I'm curious to find out what it would take for peak offsetting solar to make sense. Could you elaborate on just how much the price would have to drop and what specific needs you would have - nearby storage time, capacity factor, $/kw, etc. Just do me a favor and don't preselect the size yet. If you already have pumped hydro to swing the wind, solar's inherant match to peak would work well in place of your current pumped hydro.

August, 15 2007

Dick Maclay says

Todd, California does have pumped hydro, and there are a couple of large new projects that may be built over the next several years. Pumped hydro is used for a number of purposes. It provides ancillary services such as spinning and non-spinning reserve. It serves peak loads. And it can balance wind. Peaking needs are sufficient to gobble up existing pumped hydro capacity, and the proposed projects. So as additional wind capacity is built CTs will need to be added. We do not have enough alternative capacity to get CTs off the margin.

IF solar becomes competitive cost wise, or even nearly so, that could change the equation. Nothing is simple in this business. The pattern of solar output, price of natural gas, load flexibility, etc. will feed into determining what an optimal dispatch would look like with significant amounts of solar peaking. PERHAPS things like pumped storage could be used more for filling gaps between solar and wind in that scenario than for pure peaking. The only certainty is that a clean peaking resource at a reasonable price would make wind a more effective environmental resource.

The cost of alternatives as well as the value placed on emissions (and their avoidance) affect what we would think is a reasonable price for solar. Some alternatives, such as ice storage for commercial air conditioning are cheap. But there are probably not enough cheap alternatives (even if our industry were capable of becoming efficient) to take CTs off the margin. So it is really solar vs. CTs, including your valuation of environmental affects (valuations vary by individual). I have taken some shots at what is competitive. PV avoids T&D as well as CTs. It appears to be competitive at $2000 to $2500 per kW. Actual installations seem to come in at double that or more. Their costs vary widely. Central trough systems like Nevada Solar One are reported to cost $4000 per kW and they would probably be competitive at somewhat under half of that. Of course, if avoiding emissions is given extremely high value one could claim that solar is competitive today. If we had a cap and trade system for allocating the emissions society can accept, then I think the numbers would come out somewhere near the ones I have indicated.

August, 16 2007

Todd McKissick says

Dick, Very good assessment indeed. I would wholeheartedly agree. With that line drawn in the sand, we really only need to address how much to adjust it with any new information. One piece of history comes to mind that seems applicable.

In the 70's, we were presented with affordable and portable calculators. I remember shelling out quite a chunk for a simple 4 function one with memory. Of course, they couldn't do everything that a mainframe computer could do, but they assisted many people in doing simple calculations. Over time and through mass production, they became nearly too cheap to sell. They're now given away with business cards in places. During this time, they grew their features to the point that they now offer graphing, etc. and depending on how you categorize them, they offer portable telephone services, email, internet, radio & tv and massive music/video storage and playback. That's quite a list for a few hundred dollar device that fits in your pocket. By comparison, mainframe computers have been pretty much stagnant this whole time in both features and price.

The DG market is equivalent to the little starter calculator and it's feature growth is in development now. Thinking that the current first generation DG systems will be the standard for long is like knocking the calculator progress of the last three decades. What are the new features and how low can mass production drop the price, you ask? Basically anything you can desire in a whole house energy system is possible (technically) and most estimates by those developers suggest that it's amitorized price can drop below traditional energy costs.

Addiitonal consideration needs to be given to many unadvertised features that aren't available via central utility power too. Things like transmission and emissions avoidance, load shifting, distributed reliability and energy storage are well known, but there are many other features not being discussed. Things like reactive loading, anti-islanding safety features, building energy management, CHP water and building heating and cooling are being developed. From an economic standpoint, they shift corporate welfare to home equity which can't possibly be overstated. Future capabilities even offer a number of ways to power a car or two as well. With the current market situation of high energy prices, these features will remain in high demand which as we all know will drive competition.

How would the wind storage concerns change if an army of customer owned generators could respond to real time price information to dispatch power to the grid instantaneously? Given today's knowledge, would you go back and put your money into mainframes or the little calculators?

August, 16 2007

Dick Maclay says

Todd, two thoughts:

My father’s team developed a micro computer in the 1950s for on board navigation by ICBMs. That was the only application that could afford them then. It took 20 years before you and I could get a micro computer. Of course, a $100 calculator today is more powerful than the first computers used in the ICBMs. It takes time for even technologies we think move at lightening speed to percolate into the mainstream.

Calculators and the first micro computers had a major market advantage over DG. They could stand alone. Even with DG, the cheapest back up system is some sort of network. Problem is that the network owners and their regulators look at DG as something that requires standby charges, is dependent on the transmission system, etc. They do not understand that it is to a large degree an alternative to expanding electric transmission. This is delaying DG by a decade or two.

I may retire before DG makes significant inroads in this hide bound industry. But my children (in their 20s) should probably include DG in their calculations. Perhaps the political desire to make wind more useful will force acceleration of the efficiencies you site. But you describe a vibrant market at work, and deregulation is out of fashion. Unfairly out of fashion, since places like California slapped a "deregulation" sticker on a system designed to fail that did not at all resemble deregulation. But the perception that deregulation did not work is another factor slowing progress. If you are in a hurry my thoughts here are pessimistic. But long-run they are more optimistic than the standard view. How does all of this affect wind? If I were smart enough to know that I would have been sufficiently clairvoyant to have sold all my holdings before the market started down.

August, 17 2007

Jim Beyer says

Dick and Todd,

My electronics Professor got a surplus micro from an ICBM to play with. I wonder if it was the same one? I guess it was even cone-shaped....

Anyway, if I think about what Dick is saying, then the grid is not likely to be a source of support for DG or many other alternative energy technologies. Well, fine. That would lead one to go a more passive resistance route (maybe passive aggressive...). No connect for selling power back to the grid. Instead, concentrate on smaller systems 10-25Kwatts, and hopefully use some excess to power your PHEV or even synthesize fuel. What this does to the grid is you become a parasitic leech to it; they support your connection, but you end up rarely using any of their power, yet you can use as much as needed, should the need arise. In essence, a horrible deal for the grid. All the problems of peaking, and none of the benefits of day-to-day sales.

Hmm, how do get this back to the topic of wind. OK. Well, for smaller sites, one needs some kind of "optional" load that can deal with at least some of the power that is generated when not needed. It's either that or the grid connect (which is expensive) and all the political hogwash you have to go through to get the utility to buy back your power.

So, I think PHEVs might end up being a great catalyst for motivating further DG. If PHEVs can be built pseudo-economically (a somewhat big IF) then using spare power to displace gasoline you no longer need to purchase would be a big win for the homeowner anyway. A much bigger win that one would expect to get from a utility that burns a few less lumps of coal.

August, 17 2007

Todd McKissick says

Dick and Jim, I think there are two main points to factor in. The first being that it seems proven to me that economies of scale works much better for those shrinking things, adding features and selling more units than it does for those consolidating into increasinly larger 'things'. Besides, I've yet to ever see a 'significant' price reduction presented to the consumer due to utility scale-ups. When the public becomes aware of DG systems the do offer total cost of energy reductions, they will create the demand.

The other aspect of all this is the capacity of the DG systems we're discussing. There seems to be a presupposition that they will regularly need makeup power from the grid. This is mostly true of the publicly knows systems of today, but the end goal of these startup companies is to produce excess power to the grid all year long. The grid function then becomes one of collection and emergency backup in the case of a customer's system failure. Over time the profile of this dispatchable power will match the peak needs of the grid, so who benefits more there? Local utilities in high PV concentration neighborhoods are already dealing with the peak shifting (or softening) benefits of so much solar DG. I think it's time for utilities to embrace the concept that thousands of individual DG overproducers is a better and cheaper peaking source than a single large system of any kind. They don't have them available yet, but today's net metering and standby policies will directly affect how long it takes and what role the utilities play in 20 years.

One organization is considering an arrangement now where there is no actual generation facility for a remote Brazilian community. The localized 'grid' will be nothing more than automated interconnects which feed Bob's surplus to Joe's car, etc. If that little experiment works out, I think much of the world will certainly take notice quick.

August, 17 2007

Jim Beyer says

I think I implied that being a leech to the grid was a good thing. I didn't mean that. I did mean that this might be a way for the grid to notice DG, and perhaps work to broker a more meaningful dialogue. As it stands now, DG is an annoyance to the grid which involves subsidized interconnects producing power of very little use to them, but needing a great deal of paperwork.

August, 20 2007

Jose Antonio Vanderhorst-Silverio says

After reading the article by Sandy Smith, Communications Coordinator, Utility Wind Integration Group, some of its references, the articles by Roger Arnold, and all of the really valuable comments on all 4 articles, I like to select what J. Charles Smith wrote in the article Winds of Change as a summary message:

For many of us, this has created the necessity of a fundamental realignment in our thinking. We must understand all the implications of this and go about the business of helping to create the future.
The following are my generative dialogue suggestions (I am not my opinion) for a fundamental realignment in our thinking :

1) A carbon tax should be negotiated on a global setting, i.e. the World Trade Organization. Each country that does not apply the negotiated tax, will then free ride the global system.

2) Most of the discussions are indirectly supporting generation as a monopoly. Generation competition is not only possible, but absolutely necessary to go forward.

3) Wind generation variability is an important consideration, but wind generation uncertainty is even more important. Power system systemic risk management of system failure (system security) responds to uncertainty. Supply side management of systemic risk of system failure should be complemented by demand side management of systemic risk of system failure. See An Alternative Business Case for Demand Response and a Dominican strategy.

4) Wind generation best performance will come from balancing areas, in which generators are widely dispersed and mostly located in the distribution system. Open transmission access is insufficient to integrate wind generation in the state of the art.

5) There is thus a need for full transportation access. Transmission and distribution reintegration requires dismantling native loads, which changes the concept of a utility to wires only utility. See NERC Compliance and Power Sector Structure.

6) Fully functional and competitive wholesale and retail markets can then allow the development of the resources of the demand side. See We Need 2GRs as the Forecast is Always Wrong.

All of the above implies an emerging EWPC is Pragmatics' Winning Market Architecture and Design.

To go forward to EWPC as the End-State of the electricity industry for quite some time, I made a presentation at Carnegie Mellon University that can be found on the Grupo Millennium Hispaniola Blog, as A Generative Dialogue to Reach the End-State of the Power Industry.

August, 20 2007

Jose Antonio Vanderhorst-Silverio says

To reach "Winds of Change," please hit "Guess Editorial."

August, 21 2007

Jose Antonio Vanderhorst-Silverio says

Please see also the timely post Industry Structure to Face Climate Change Challenge.

July, 20 2008

Thomas Saidak says

To every problem there is a solution and to every solution there are problems... The standard nuclear reactors being built today are water hogs. MIT Review articles note that the US will only be able to accomodate 20 to 35 additional nuclear power plants. No one seems to be planning on building a pebble bed reactor in North America anytime soon. Hydro electric depends on rain/snow fall. We have had significant problems with that here in California over the last two decades. Geothermal is a water hog as currently envisioned. Photovoltaics only work during the day in sunny weather. As I am writing this in sunny San Jose, we have 100% cloud cover at or about 2000 ft. In July. In California, we have rolling blackouts only during AC weather, so in building new plants, we are purposely building what are in effect part time plants. Our daily consumption varies widely. With wind, the discussion around storage as a solution to timing and variability quickly take center stage. It strikes me that making storage a grid issue instead of a generator issue would resolve alot of problems. Fewer plants, increased predictability for grid operators and possible back up for plant or grid failures.

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