Smart Grid Operational Services The Impact Of Renewables On The Electric Grid POV


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Smart Grid Operational Services The Impact Of Renewables On The Electric Grid POV

  1. 1. Energy, Utilities and Chemicals the way we see itThe Impact of Renewableson the Electric Grid
  2. 2. The regulators are coming, the it is an engineering issue, in others These four categories of renewablesregulators are coming and they are it is a people issue. No generation bring different issues to the gridgoing to force changes in our industry. will be installed and operate without and have different levels of gridWith political requirements to reduce facing some issues and problems. friendliness. The location of thecarbon, deal with global warming, connection and the ability to producebe greener, allow local participation To really look at the impact of power on demand makes thein the power grid, and try to manage renewable sources on the electric grid, difference in how friendly they are.the cost of energy, regulators are you need to separate the renewableschanging the requirements for what into several categories. In this S-Centis allowed on the grid. Renewable document, we have made a simplistic The S-Cent and the V-Cent are bothgeneration is the buzz word today separation into the following categories: connected to the transmission gridand regulators do not want to be left and have the ability to take advantagebehind. In the US, more than 30 1. Schedulable central station of the traditional control systems andstates now have renewable portfolio generation (S-Cent) – This monitoring. The existing SCADAstandards—mandatory percentages of includes biomass and other systems and protection schemes arepower that have to be produced and alternative fuels that can be used capable of supporting both of thesedelivered from renewable sources by in place of fossil fuels, and existing types of generation. S-Cent is sospecific dates. In some cases, the RPS fossil fuel plants may be able to be similar to conventional generationrequirements kick in as soon as 2010, retrofitted to consume them. For that it offers few or no issues inin others the first real requirement is instance, wood chips replacing integration into the grid. Since itin 2025. But in any case, in the US, coal, ethanol replacing oil, or is so simple to integrate, where thethe state requirements will require biogas replacing natural gas. fuels are available and economicallythat an additional 1 percent of the 2. Variable Central Station viable, it should be considered as thetotal electric power consumed in Generation (V-Cent) – Wind farms first choice in deployment. In mostthe US be produced by renewable are the best known examples of this cases, the economic model for S-Centsources each year. In Europe, triple class of asset and are the most matches that of conventional fossil20 will force a similar requirement. widely deployed renewable generation. A sample of the facilitiesThe manufacturers of renewable generation sources today producing that fit into this include:generation devices are all running electricity. Large solar and waveat full capacity and increasing that power installations also fit into this 1. Large wood-fired power plantscapacity. GE Energy will double category. The assumption is that 2. Garbage and post consumer wastewindmill production in 2008, again V-Cent would be connected to the incineratorsin 2009 and yet again in 2010 and transmission (high voltage) network. 3. Landfill gas generation facilitiesthey are completely sold out until 3. Schedulable Distributed 4. Pumped hydro facilities2012. Other manufacturers are in Generation (S-Dist) – This isa similar situation and the type of 5. Large hydro facilities small scale generation that usesrenewable generation they produce 6. Run of the river current farms. renewable fuels; normally, thedoes not matter. Incentives and generation facilities would besubsidies, rather than real economics, These facilities offer very few found on farms, in businesses andare driving the sales, as well as challenges from a grid management in homes. One good exampleregulatory requirements. point of view, but they do offer would be wood-fired combined heat and power. The expectation other challenges for site approvalThis installation of renewables will and operations. In some areas, would be that the generation cannot be without problems. None are incinerators that were installed only be turned on and off as needed.impossible to deal with, but some a few years ago are being shutdownare very expensive to deal with and 4. Variable Distributed Generation because of protests by people who liveothers just take time and energy. (V-Dist) – This is the category that near the facility.Renewables will have an impact on most environmentalists meanthe whole utility value chain and how when they discuss the next One very clean garbage incineratorit operates. No utility is exempt, and generation of the electric network. in a major city has been shut downit does not matter if the market is Solar Cells on a homeowner’s roof, after only 8 years of operation becausefully regulated or fully de-regulated, or a small windmill in the people living in the area did notthere will be an impact. In some cases backyard or barnyard.2
  3. 3. Energy, Utilities and Chemicals the way we see itlike the noise of the trucks and the kind of forecasting. Forecasting the generate power. People mostly do notlook of the facility in their industrial output of V-Cent is critical, as it like to live in areas with strong andneighborhood. The facility exceeded determines when to fire up the large steady winds, it makes living tougher.every standard that could be applied, fossil plants to support days when This means that in most cases theand trucks were only allowed to the wind is either going to blow locations that have the best wind aredeliver trash from 10 AM to 4 PM, a too strongly or not at all, or as in not the places that have high densitiestime when few people were home. the case of photovoltaic, when the of people or power consumption. For storms are rolling across the service the grid operator, that means buildingV-Cent territory hiding the sun. The global extensions to the transmission grid.Like the S-Cent facilities, they are understanding of cloud paths and High voltage transmission lines areconnected to the high voltage network detailed wind forecasts is less than not cheap—they can cost millionsand produce large amounts of power. perfect, and as such, the impact of of euros a kilometer; for example,Also, like the S-Cent facilities, they weather on V-Cent is likewise, i.e. less at AEP, one project is budgeted atare highly visible on the horizon than perfect. 5.5 million dollars a mile. Add toand cannot be hidden from view the cost the fact that wind farmseasily. Unlike the S-Cent facilities This less than perfect understanding only generate about 40 percent ofthey run when the environment is means that the utility has to be ready the time, and the transmission linkright, and not when they are needed. to react to changes in power output to support a plan like the PickensFor example, wind has to blow fast on a very short timeline; in some plan (a plan to replace all the fossilenough, and yet not too fast in order cases the swing can be hundreds of generation in the US with windto generate power. In most cases they megawatts in a matter of minutes. power and use the natural gas thatoffer power from 7 to 40 percent of If utilities want to see this power currently makes electricity and heatsthe time, depending on the location swing in operation, visit Tennet the homes to power automobiles) in theand the type of resource. These grid operator in the Netherlands and US would need to connect to threesystems require some level of other watch the power flow on a stormy day times the number of megawatts ofgeneration to provide support, since on the interconnector with Germany. wind power than it would for coalthe power they produce comes and Because conventional generation generation. In other words, to usegoes on a change in the weather, does not react as quickly as V-Cent wind to provide ancillary servicesand the load they support may not. typically does, the grid operator on (e.g. maintaining voltage, frequencyThe estimate in Colorado is that the transmission network has to and the integrity of the Alternatingit takes one megawatt of running deal with rapid changes in voltage Current (AC) wave form – all requiredgas-fired generation to support 2 on the grid. In some cases, where to let device work right and not burnmegawatts of wind generation in the penetration of wind or solar is out)—by spreading the wind farmsthe state. This ratio has a big impact small, the rapid swing is a small over a wide area that receives strongon the carbon footprint of the final part of the overall power flow and wind—would cost at least threedelivered power. While it is cleaner can be safely ignored. In Texas and times the cost of transmission forthan a new coal-fired power plant, the Spain this is not the case, and both a new nuclear plant. No one likesestimate is that to get the equivalent have almost lost the transmission large steel towers in their backyard,of 2 megawatts of new coal-fired grid to blackouts because of wind so you can expect that even ifpower plant, 1 megawatt of gas- power—in Texas it was the sudden people embrace wind mills, theyfired generation and 2 megawatts of and unexpected drop in wind power will pan the transmission corridors.wind generation have to be installed. production and in Spain it was too With these new large transmissionLarge variable central generation can much wind generation on a wonderful links, there are issues with powerbe monitored by existing SCADA spring Sunday when people decided quality and voltage management onsystems and controlled by existing to go outside and shut off most of the transmission network that didenergy management systems that their electric devices and lights. Swift not exist before. Proper ancillaryare in operation by the transmission action by the grid operator saved the services can help fix this, but theoperator today. What the existing grid in both cases, but it was close. technology to use one wind farmsystems cannot do is to predict with to support another wind farm forany level of confidence what the Geographically wind blows where it ancillary services, like voltageoutput of wind power will be 24 to blows and we do not have the skills support or frequency management48 hours in advance. New systems to modify the global weather patterns is not commercially available yet.have to be installed to support this to put the wind where we want it to The global industry has worked veryThe Impact of Renewables on the Electric Grid 3
  4. 4. hard to manage power quality, and engines. In the future, these may be generate a single phase of power. Thatthat has allowed homeowners to have powered by bio-diesel and ethanol, means that the power flows out of thecomputers and other digital devices making them technically renewable generator onto a single phase of thein their homes and businesses. If the sources. There are literally thousands grid. If this generator is installed onnetwork power quality falls enough, of internal combustion generators the right phase, it can be very usefulthe utilities will have to either turn to in the distribution grid today. in balancing the load between phases;using high voltage DC transmission Companies like EnerNoc were formed unfortunately you have a betternetworks and converting the power to install controls and schedule their chance of winning in Las Vegas thencloser to the customer into AC power, operation on the grid. This resource you do in getting all the generatorsor individual customers will have to has been ignored in the past because installed on the right phase, since thereturn to using motor-generator sets the distribution grid is not ready to owner of the generation has controlor solid state power electronics to handle two way power flows, when in of their device and not the utility.manage power quality. These costs fact, in many cases the way they are This can lead to very large phasehave not been factored into any of the used is to disconnect the customer imbalances and big differences inrenewable portfolio standards or other from the grid and let them run as a voltage on a phase to phase basis.plans that push for a high fraction stand-alone island. Phase imbalance normally leads toof variable sources. These barriers wasted power, in some extreme casesare not insurmountable, but they do Changing the grid to support S-Dist as much or more than the distributedneed to be honestly addressed with means changing the relaying and generator creates.research and engineering. the protective devices installed in the grid to allow power to flow Further, the inverters have anotherIn the future, as more and more of the backwards (on the grid). Today the issue that is yet to be tackled—theygeneration becomes V-Cent the ability grid is designed to allow power to create harmonics that can be harmfulof the operator to prevent a blackout flow one way, from the high voltage to the operation of the grid as wellwill decrease and more of the grid network to the customer; as S-Dist as appliances and computers thatmay be at risk. The most common is installed and operated attached to are installed on the grid. Thesegeneration sources in this category are the grid, power has to be able to flow harmonics can shorten the life of thewind and photovoltaic farms, two of the in both directions. In a typical grid, appliances and computers. Today,fastest growing sources in the world. there is a protective device for every harmonics in the low voltage network 100 to 200 customers; changing these are normally ignored, since the cost toS-Dist devices is a labor-intensive process solve harmonics problems outweighsSchedulable distributed generation that can interrupt the power to all the value of fixing the problem.differs from V-Dist in that it is done the customers that are downstream As large screen television sets andon a more “human” scale, typically of that device. The next issue is how other new solid state electronicin less than 1 megawatt sizes. This to pay the generation owner for the devices are installed and add theirmeans that it is not connected to power they generate. When a utility harmonics to the grid, the impactthe high voltage network, but rather islands the customer, it is easy—they of harmonics is increasing. Sinceto the low voltage or distribution simply pay them for removing their harmonics have a negative impact onnetwork. Because it can be scheduled, load from the grid, and not for the the life of consumer devices this canit offers the ability to provide highly kilowatt hours of power generated. mean that the average life span ofdistributed power, close to where As we integrate S-Dist, you need to many of these devices is decreasing.the customers consume it on the create a measurement system and Eventually, the industry will havegrid. This has a number of beneficial change the tariffs to support the to tackle harmonics issues. Mostimpacts, if the S-Dist is built to a plan payment of customers who generate utilities operate under regulationsthat supports the needs of the grid power for you. that allow them to charge the creatorand it is planned into the distribution of harmonics the cost of fixing thegrid. Unfortunately, this is seldom S-Dist has a further problem—most problem it or force them to fix thethe case; homeowners and business of these generators use electronic harmonics themselves; however,owners decide they want to install inverters to take the DC output of the almost no utility actually bothersgeneration and they do so. Today, generator and turn it into AC power to ensure either today. These issuesthe most common sources are not on the grid. Because of the small size may be an added cost on S-Dist thatrenewable at all, but rather gasoline- of the generator, it is too expensive to may delay installation or minimizeand diesel-fired internal combustion create 3 phase power, so they instead operation in the future. Harmonics4
  5. 5. Energy, Utilities and Chemicals the way we see itare not just an issue of S-Dist, V-Dist the peak would be much higher than Most of the best places to put windhas similar issues as do many of the the cost to generate power at a central mills and solar cells are out in thenew classes of consumer electronics. station—further reducing the number suburban and rural areas where the of hours that the S-Dist might run. people density is less, and that meansBecause the S-Dist is installed in the the power consumption is also less.distribution network, the transmission Finally, these generation sources In many cases, this means the size ofSCADA system does not offer the ability typically have a site approval the wires in the distribution grid areto operate or monitor these generation problem—since most are diesel also smaller. To put larger numberssources. Instead, the operator of the and gasoline engines running of V-Dist units in the rural areas andlow voltage network will have to install bio-fuels, they are noisy and smell move the power to people who willa system to monitor and control these (imagine McDonalds French fries use it may involve re-conductoring—sources and provide information to for bio-diesel). Many people do not replacing the physical wire in thethe Energy Management System that want to see them installed in their distribution grid so that it will carrynormally resides in the transmission neighborhood and even fewer people more power than it does today. Foroperations center. Some utilities are want to hear them run at 3 o’clock in an overhead system, where the lineschoosing to allow a third party to do the morning. are up on poles, re-conductoringthis work for them, while others are can cost as little as $100,000 a mile.attempting to install the infrastructure V-Dist For underground systems, thatto support S-Dist. The Distribution Finally there is V-Dist, the kind number can run into more than aNetwork Operators (DNOs) in the UK of renewables that most people million dollars a mile. Companiesalready have these systems installed, think of when you mention like HydroOne in Canada made thebut have yet to use them for this renewable generation—human-scale decision to re-conductor years agopurpose. They are generally well ahead renewables that should blend into and made it a multi-decade programof most of the rest of the industry in the neighborhood. These solar and to replace thousands of kilometers ofhaving the infrastructure to support wind powered devices are owned by wire when they did maintenance.these sources. business owners and homeowners. They are deployed in the low voltage Unlike the V-Cent, these systems areLoss of power from a system failure network and suffer from all the same maintained by the homeowner andshould cause most S-Dist systems problems that S-Dist does. This many of them find they do not get theto automatically disconnect from includes the issues with harmonics power output they were promised bythe grid, since they seldom are large and with phase imbalance. the salesman; so they do not make theenough to support the entire load money they expected and hence doin the remaining section of the grid They have even had issues with smell not maintain the generator. This leadsthat they are now connected to. This and noise (for instance, solar cells to a collapse in the capability of themeans that while the customer that that cooked tree sap giving off strong system to make power and can makeowns the S-Dist has a higher level of odors and windmills that make noise the generator even more erratic then itreliability, the rest of the customers all night long). In addition, these was when it was first installed. One ofdo not. Most S-Dist is very useful devices pose another problem for the the first components to typically fail isfor shaving the peak—i.e. reducing grid operator—they run when the the islanding device and the inverter.the demand for a section of the grid environment is right and do not run The failure of these devices does notwhen the demand for power is at its when it is not. They use the grid like typically isolate the device, but ratherhighest. This is very useful when the a large battery, putting excess power they fail most often providing DCgrid is reaching its limit for providing into the grid and drawing power power into the grid even when theypower. In the case where this is all the from the grid when they do not make should be islanded. The failure of theS-Dist is being used for, it might run enough. In similar cases, going from power electronics creates a hazardas much as 200 hours a year. This is a net generator to a net consumer can for the lineman who is dispatcheda huge capital investment for roughly take seconds. This works well when to fix the network outage, since they2% of the year. Most customers who the percentage of power produced have no clue that the power is stillwould install S-Dist would do so for from V-Dist is small, but as the flowing through the line and manyreliability rather than to support peak percentage increases there will need transformers will step up the voltageshaving. In many cases, the price that to be real batteries installed on the for this distributed power. The abilitywould have to be offered to the S-Dist grid, and that is a whole different to monitor the health of the powerowner to run their generation to shave story with its own issues. electronics—both the inverter andThe Impact of Renewables on the Electric Grid 5
  6. 6. ABILITY TO BUILD COST TO OPERATE EMISSIONS LOAD SUPPORT Capital Costs (Kilowatt of capacity) USD Wildlife Impact (Beyond Emissions) Cost per KWH (cents - USD) Similar plants in production Source for cost per KWH Decommissioning costs Source for capital costs Technology Readiness Foreward fuel price Public Acceptance Ancillary Services Typical Size (MW) Fuel Competition Fuel Availability Fuel Efficiency Cooling Water Dispatchable Time to build Schedulable Capital Cost Particulates Lead Times O&M Costs Ramp Rate Reliabity Site Size Mercury Waste Sulfur CO2 GENERATION SOURCE Baseload Conventional Coal 600 1534 2 5.2 1 Nuclear 1000 3540 1 7.8 1 Pebble bed Nuclear 200 1000 4.5 Hydro 500 NA 1551 2 Biomass 600 2809 2 Biogas 300 1897 2 Combined Cycle Natural Gas 300 717 2 7.2 1 Simple Natural Gas 200 500 2 Clean Coal NA 2537 2 9.6 1 Clean Gas NA Petroleum 300 717 2 GeoThermal 1110 2 Concentrating Salt/Solar NA Peaking Aero Gas Turbine 25 473 2 Diesel 5 1021 2 Fuel Cells 1 5374 2 Gasoline <1 1227 2 Pumped Hydro 300 NA NA 1200 3 Variable Photovoltaic <1 NA 5649 2 Thin Film Photovoltaic <1 NA 1000 6 Wind Mills 3 NA 1434 2 8.8 1 Wave Machines 15 NA 5040 7 Concentrating Solar 50 NA 3744 2Sources1) Electricity generation costs and investment decisions: A REVIEW; Dennis Anderson; Imperial College Centre for Energy Policy and Technology; Feb. 20072) EIA Report #: DOE/EIA-0554 (2008)3) Shaping & Firming Wind Energy with Electric Energy Storage by Dr. Robert B. Schainker; EPRI; Nov. 20064) A Future For Nuclear Energy – Pebble Bed Reactors by Andrew C. Kadak, Ph.D.; MIT; April 20045) Note the first 165 MW pebble bed reactor in South Africa has a 8400 USD per KW price including R&D and all the costs associated with a first time project6) PES Wiki -
  7. 7. Energy, Utilities and Chemicals the way we see itislanding device—is critical to the the regulator to get a way to incent as well as developing the operatingsafety of people working on the people to put them in the right places, rules is another significant chunksystem, and a simple fine for failure or for the utility to install and support of work. Knowing what is reallyto maintain the system is not enough installation in the right places. happening in the distribution networkto remove the human hazard that is more than just the renewable issue;exists. This human hazard can exist Dealing with variability is tough. most of the distribution networkwith S-Dist as well, but empirical data The choices are ancillary services, has very little in the way of sensorsfrom working with both S-Dist and demand response, or storage. To available to provide information onV-Dist indicates that the S-Dist sees date there are no good answers for what is happening. Putting this issuefewer failures and more maintenance storage, although the battery industry on to renewables is unfair, but it is athan V-Dist installations. keeps promising that in 5 years they gating item for successfully installing will have an answer—this started S-Dist and V-Dist. Smart Metering is aSummary in the 1970s and continues to be a step in the right direction for sharingRenewable generation is an important 5 year promise. Demand response this cost.part of the future for the electric means installing devices that eitherindustry—we can not avoid it and provide information or control in the The good news is that nothing newwe cannot hide from it. We have homes. This is part of many smart needs to be invented—only improvedto work through these problems metering deployments. Finally, there and deployed (with the exception ofand make integration of renewables is ancillary service—burning fossil storage). Renewables are a key part ofeasy. IEEE-1547 provided the basic fuels to support the integration of fixing the carbon issue and providinginterface for renewables to the grid, variable renewables in the grid or electricity where the cost of powerso the interconnection, the largest holding hydro facilities in reserve to is not tied to the cost of fossil fuels.stumbling block a decade ago, has provide instant voltage support. This Fuel price swings and the move tobeen solved. Now the issues move is a question that will take research, carbon markets will tend to accelerateto the integration of the renewables planning and operational work to the move to renewable. The new USinto the operation of the grid. Some provide an answer for, and it will not Energy Team under President Obamaof the issues can be solved with solve the “too much power” issue on a will also accelerate this move in theplanning—relaying and protection day when customer demand drops to US and that will have an impact onschemes can be redesigned and the almost nothing. the rest of the world. Regulators,new standard can be deployed as customers, utilities, manufacturerscircuits are maintained or built. This Harmonics, reactive power, and and independent power producersis an important step in being ready power quality are harder problems. will all have to work together to makefor distributed generation, and not The transmission operators this work. For more than 100 years,just renewable generation. Working manage reactive power and many we have been improving, perfectingwith regulators to determine how to of the sensors on the transmission and investing in the existing electrictest the status of power electronics networks exist to handle reactive grid. One estimate for transmissionand what the utility is allowed to power. Capacitor banks are helpful alone indicates that the US wouldrequire for the safety of workers is in managing reactive power, but have to spend over $900 billion toalso an important step. For example: typically they do not exist out in the support a plan like the Pickens Plan.Can the utility cut the wire to the distribution network and the sensors Globally, it would amount to trillionspower electronics and remove it, if the and controls to use them effectively of dollars.islanding device is not functioning also do not exist. Harmonics andcorrectly? What are the rules for safely power quality for the smaller We have a long way to go, we need tooperating these devices and ensuring customer to date have been ignored make the journey, but knowing themaintenance? This will have to be as too expensive for the benefits issues we will encounter along thesolved for each utility, as there is no delivered. The question is when the way and planning for them in advanceuniversal answer. Site approval is tipping point is reached and these will make the journey more likelyan issue that will not go away, and problems have to be sorted out. to succeed. This is a journey that wein most cases it is the responsibility need to take, let us all do it with theof someone other than the utility. Integration of hundreds or thousands highest possible chance to succeed.Putting the devices on the right of generation sources into existingphase, if they are single phase, again Energy Management Systems andis an issue that takes working with Distribution Management Systems,The Impact of Renewables on the Electric Grid 7
  8. 8. About Capgemini and the Collaborative Business Experience Capgemini, one of the 8.7 billion and employs over 88,000 world’s foremost providers of people worldwide. consulting, technology and outsourcing services, enables its clients to transform With 1.15 billion euros revenue in 2007 and perform through technologies. and 10,000+ dedicated consultants engaged in Energy, Utilities and Capgemini provides its clients with Chemicals projects across Europe, insights and capabilities that boost North America and Asia Pacific, their freedom to achieve superior Capgemini’s Energy, Utilities & results through a unique way of Chemicals Global Sector serves the working - the Collaborative Business business consulting and information Experience® - and through a global technology needs of many of the world’s delivery model called Rightshore®, largest players of this industry. which aims to offer the right resources in the right location at competitive cost. More information about our services, Present in 36 countries, Capgemini offices and research is available at reported 2007 global revenues of EUR more information please contact:Gord ReynoldsPractice LeaderSmart Energy 416.732.2200 EUC20081215_473© 2009 Capgemini. All Rights Reserved. No part of this document may be modified, deleted orexpanded by any process or means without prior written permission from Capgemini.