TODAY’S STUDY: THE STATE OF WIND AND SOLAR FORECASTING

A Review of Variable Generation Forecasting in the West, July 2013 — March 2014

R. Widiss & K. Porter and Dr. Debra Lew & Dr. David Hurlbut, March 2014 (Exeter Associates and NREL)

Executive Summary

This report is based on a series of interviews with 13 operating entities (OEs) in the Western Interconnection about their implementation of wind and solar forecasting, jointly referred to as variable generation (VG) forecasting. This piece updates a report issued by the National Renewable Energy Laboratory (NREL) in 2012; it also covers several additional topics including sub-hourly scheduling, grid operator training, and forecasting for distributed solar resources. As in the 2012 report, the OEs interviewed vary in size and character; the group includes independent system operators, balancing authorities, utilities, and other entities that rely on VG forecasting.

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VG forecasting is widely considered to be a key means of integrating wind and solar power efficiently and reliably as these resources become increasingly common. Indeed, in a recent report, grid operators from 18 countries identified wind forecasting as “the most important prerequisite for successfully integrating wind energy into power systems” (Jones 2011, p. xxiv).

VG forecasting remains a relatively new phenomenon in the West. Ten of the 13 OEs interviewed for this year’s report began using VG forecasts in 2007 or later. Each currently uses a wind forecast. In anticipation of rapid growth in solar generation, five OEs have recently begun working on in-house solar forecasts and two are utilizing outside sources. This report serves as a means for these companies to compare VG forecasting practices, lessons learned, and priorities with one another, as well as to share their experiences with state and federal regulators, market participants, national laboratories, and non-governmental organizations.

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Highlights

Costs and Benefits – The costs of wind forecasts have dropped dramatically since the 2012 report. This decline coincides with a shift toward testing or utilizing multiple vendors. Many of the OEs interviewed no longer view VG forecasting in a cost-benefit framework, regarding it instead as a necessity for maintaining electric reliability and scheduling resources effectively.

Cost Assignment – Only a few respondents partly or fully recover forecasting costs from variable generators. Many simply absorb the costs, possibly viewing them as relatively minor. However, the reportedly high cost of individual solar plant forecasts prompted at least one OE to turn to in-house forecasting.

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Forecast Accuracy – Wind forecasting accuracy continues to improve incrementally. Participating OEs credit these gains to improved forecasting techniques and models, seasoned vendors, and growing portfolio size, all of which smooth the variability in VG output. Solar forecasting is at an early stage in the West, but at least one company is beginning to track solar forecasting accuracy.

Forecasting Uses – Nearly all interviewees use their wind forecasts for day-ahead unit commitment—a striking change since the 2012 report. This was consistent despite the entities’ diversity in size, proportion of renewables, and average monthly load. Intra-day unit commitment and reserves planning are the next most common uses, followed by a diverse array of uses often unique to a given entity.

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Data Collection – Participating OEs have made few expansions, if any, to the types of meteorological data (wind speed, direction, temperature, pressure, humidity) and turbine status data they require of wind generators. However, two OEs have recently taken steps to increase the speed of data transmission from their generators, and reported that this change has greatly enhanced the value of their wind forecasts. Because solar forecasting is at an early stage, only a small number of responding OEs have solar data requirements in place.

Curtailments and Outages – Most interviewees factor turbine availability and/or outages into their forecasts so that they represent what generators are capable of producing, even if VG output is curtailed. Less than half of the OEs describe using curtailment information after the fact for calibrating forecast models and calculating performance metrics. Probabilistic Forecasting – Participants report that both ensemble forecasts and confidence intervals (CIs) are commonly used to address forecasting uncertainty. Yet many system operators reportedly ignore the CIs provided to them, choosing instead to use a single likeliest production value.

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Distributed Solar Production – Distributed generation (DG) is commonly “invisible” to system operators, particularly for behind-the-meter resources connected at customer sites, which are netted out with the customer load. These resources cannot usually receive dispatch commands. Six of the OEs interviewed view the development of methods to forecast distributed solar production as an imminent need, and two see it as an eventual need. No consensus on how to forecast distributed solar generation has emerged.

Control Room Integration – Displays of VG forecasts in OE control rooms are nearly universal. Typically, these are automated feeds, sometimes provided by third-party forecasters. These displays are often accompanied by real-time weather or real-time generation data. Half the organizations interviewed are integrating forecast values directly into operations tools such as an Energy Management System (EMS).

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Staff Familiarity – Though formal training is rare, staff members often coach their colleagues on an as-needed basis. System operators have developed a sense of familiarity with VG forecasts at most of the organizations interviewed. Four OEs also employ meteorologists to aid in interpreting VG forecasts.

Advice and Lessons Learned – Respondents’ advice for other utilities includes starting sooner rather than later as it can take time to plan, prepare, and train a forecast; setting realistic expectations; using multiple forecasts; and incorporating several performance metrics. Potential Regional Initiatives - Several of the OEs interviewed are against the creation of formal standards or guidelines for forecasting, suggesting that these would stifle innovation and impose “one-size-fits-all” methods upon unique situations. Others suggested that guidelines for data collection or a guideline determining resource adequacy for reserves would be helpful. A small number of interviewees advocated for further research and development (R&D) investments in forecasting.

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Forecast Sharing - OEs were also split on the idea of sharing forecasts with other OEs. Some suggest that sharing forecasts and data would help improve VG forecasting. Others contend that sharing forecasts will not have much value unless reserves can be traded through such mechanisms as Energy Imbalance Markets (EIMs). Still others view VG forecasts as a source of competitive advantage for recipients and would oppose sharing them.

Sub-Hourly Dispatch - The changes documented since the 2012 report have been remarkable. Yet, it is also worth noting one practice that has not changed. Outside of the West, regional transmission organizations (RTOs) are now dispatching wind in five-minute markets as opposed to hourly schedules in the West, except for the Alberta Electric System Operator and the California Independent System Operator. The RTOs outside the West use equally fast forecast updates, taking advantage of the fact that forecasts are more accurate in short-term increments. Industry initiatives such as the EIM encompassing the California Independent System Operator, Nevada Power and PacifiCorp, as well as regulatory initiatives such as Federal Energy Regulatory Commission Order No. 764, may accelerate the adoption of this practice in the West.

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QUICK NEWS, July 30: ILLINOIS LAWMAKERS GIVE SOLAR $30MIL; WIND BRINGS DOWN POWER COSTS IN MICHIGAN; VIRTUAL POWER PLANT MRKT TO QUINTUPLE

ILLINOIS LAWMAKERS GIVE SOLAR $30MIL BOOST Illinois Investing in Solar Power

June 28, 2014 (AP via CBS St. Louis)

“…[The Illinois Power Agency] will buy up to $30 million worth of solar power and pump it into the energy mix for electricity customers under legislation [just] signed into law…[The new law] establishes a competitive process to purchase the energy from new or existing solar installations, which could include rooftop solar panels that homeowners can use to sell any leftover power back to the electricity grid…The Illinois Power Agency was set up in 2007 to develop plans for buying renewable energy for utilities to feed into the grid. The money for the solar power purchases comes from the agency’s Renewable Energy Resources Fund, which is made up of clean energy fees paid by power suppliers…” click here for more

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WIND SURGES, BRINGS DOWN POWER COSTS IN MICHIGAN Michigan's wind energy industry soaring

Frank Witsil, June 28, 2014 (Detroit Free Press)

“The shift to renewable energy sources in Michigan — particularly wind — has picked up in the past few years…One reason: [Wind energy is] about half as expensive to produce than utility companies initially expected, down to as little as $50 a megawatt hour last year from more than $100 a megawatt hour in 2009, according to the Michigan Public Service Commission...Michigan is home to about 120 companies that supply wind components and employ 4,000…A [2008] state law that requires 10% of electricity produced come from renewable sources by the end of next year has increased demand and helped propel the construction of wind farms…[Since 2008], utilities have invested more than $2.2 billion in renewable technology…There are now more than 20 wind farms in Michigan that are operational and in development…Michigan’s growing wind business has meant falling prices for residential consumers…This year, largely because of the lower cost of wind, DTE has reduced its [renewables] surcharge from $3 per meter a month to 43 cents, and Consumers Energy is eliminating its surcharge altogether…” click here for more

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WORLD VIRTUAL POWER PLANT MRKT TO QUINTUPLE Virtual Power Plants Demand Response, Supply-Side, and Mixed Asset VPPs: Global Market Analysis and Forecasts

2Q 2014 (Navigant Research)

“…Successful strategies to manage [the increasing two-way complexity of distributed energy resources (DER)] are being deployed today all over the world. One such strategy is a virtual power plant (VPP)…[which combines] a rich diversity of independent resources into a network via sophisticated planning, scheduling, and bidding of DER-based services…Several recent trends are creating an environment conducive to VPPs…However, challenges to commercial rollouts of VPPs remain, including the lack of reliance upon dynamic, real-time pricing and consumer pushback against the smart grid…Navigant Research forecasts that total annual VPP vendor revenue will grow from $1.1 billion in 2014 to $5.3 billion in 2023 under a base scenario…” click here for more

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Check Out The SunShot

“…We’re three years into a decade long effort and we’re already 60% there…” And “the great news is, you don’t drill for solar, you don’t mine for solar…” From U.S. Department of Energy via YouTube

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Poll – Voters Won’t Go For Climate Change Deniers

“Only 38% of voters will vote for a candidate who denies human-caused climate change…I don’t know if I should be happy it’s less than 50% or distraught that it’s almost 40%.” From David Pakman Show via YouTube Tweet

Peter Sinclair On The Real News Network

On the strength of his superb work on Climate Denial Crock of the Week series, our friend Peter Sinclair has emerged as a national spokesperson. From TheRealNews via YouTube

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WHAT THE LITTLE PTEROPOD TEACHES

What ailing pteropods tell us about climate change

Larry Taylor, June 25, 2014 (LA Times)

“…[Tiny seagoing snails called pteropods] make up the base of many oceanic food webs. Without them, everything in the food chain above them suffers…Unfortunately, [t]heir shells are literally dissolving, killing them off in astounding numbers…The cause of this die-off, ultimately, is believed to be the rising levels of carbon dioxide…that turns the oceans more acidic, slowly disintegrating [shellfish like the pteropods]…[A]bout 250 million years ago, the oceans endured similar changes…Unfortunately, this past acidification event coincided with the Permian-Triassic extinction…[that] wiped out more than 90% of marine species. The planet took millions of years to recover, the history of life was forever altered…[and now] the Earth is changing…in a way very similar to what caused the greatest extinction in history…[Though it] may seem like a slow progression, it's a mere instant in Earth's history, and the environmental changes we're causing far outstrip the ability of life to adapt...[L]et's not overlook or dismiss these initial symptoms…We're growing ever closer to pushing our home over the edge, perhaps into another mass extinction…” click here for more

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$1.7BIL OCEAN WIND BUY-IN FOR UK GREEN BANK

Britain's green bank to launch 1 billion pound offshore wind fund

Sussana Twidale w/Mark Potter, June 24, 2014 (Reuters)

“Britain's government-funded bank investing in green energy projects will launch a 1 billion pound ($1.7 billion) fund dedicated to buying stakes in operational offshore wind projects in the country…The Green Investment Bank (GIB) participation is a boost to Britain's offshore wind sector which has seen a series of project cancellations over the past few months…Britain already has 3.6 gigawatts of installed offshore wind capacity but is counting on the development of other wind farms to help it cut carbon emissions in the electricity sector…The Bank hopes the fund will help attract new investors to the offshore wind market such as sovereign wealth funds and pension funds…The GIB is already a major investor in offshore wind…” click here for more

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DONKEY-TOP SOLAR IN TURKEY

Solar energy helps Turkish herders stay connected

June 24, 2014 (RFD-TV)

“Herdsmen in Turkey are going to the fields with their sheep and goats armed with 21st century technology…[D]onkeys are now carrying solar panels…The panel generates enough electricity so the herdsman can use a computer to get the latest information on the weather…The electricity is also used for light. The herdsmen said the light is especially helpful during the birthing season…The solar power pack can also charge cell phones. The solar project was developed by a Turkish energy company and the Provincial Sheep and Goat Breeders Association…The company designed a special "plug and play" solar pack [at donkey-carrying weight]…” click here for more

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IT’S FINAL: GE BUYS FRANCE’S ALSTOM

GE Wins Alstom Energy Bid With France Buying 20% Stake

Richard Clough, Francois de Beaupuy and Alex Webb, June 22, 2014 (Bloomberg News)

General Electric Co. finally completed its long pending $17 billion purchase of Alstom’s gas turbine operations and formation of joint ventures with Alstom’s steam turbine, renewable energy and electrical-transmission businesses…The two factors allowing GE to win its bidding war with Siemens AG for Alstom were (1) GE turning over its rail-signaling operations to Alstom for $825 million, and (2) convincing shareholder Bouygues SA to sell as much as 20% of its ownership in Alstom to the French government…French law permits state intervention to block acquisitions of companies deemed to be of national importance and the Hollande government was blocking completion of the transaction until it was assured of 20% voting rights and the appointment of two government-named board members…This is GE’s biggest acquisition ever…Alstom built the French electricity grid and makes its high-speed trains and the turbines that generate most of its electricity… click here for more

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THE PAULSON PIECE, THE BRIEF

HANK PAULSON: Climate Change Risk Is The New Housing Bubble

Rob Wile, June 22, 2014 (Business Insider)

"Few were more intimately involved with manging the financial crisis than Hank Paulson, President George W. Bush's treasury secretary…In a new op-ed in the New York Times, Paulson says he's seeing the same stresses that nearly brought down the banking system, and which led to the Great Recession, are playing out in climate…[2008’s excess debt is 2013’s excess greenhouse gas emissions; flawed incentives to borrow for financed homes are today’s dependence on carbon-based fuels; the 2008 financial experts nobody listened to are 2013 climate scientists; and 2008’s risk to the global economy is today’s looming global climate disaster]...Paulson calls for the creation of a carbon tax, which he…[calls a ‘conservative’ solution that] allows market forces to put a price on allocating resources toward or away from addressing the problem…Paulson acknowledges that the U.S. alone can't address the situation — but that no one else will be moved to do so if it doesn't take the lead. And he takes his own Republican Party to task for not taking the crisis seriously, saying that the short term economic consequences will be swamped by the long-term ones that would come from doing nothing…” click here for more

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THE PAULSON PIECE, PART 1

The Coming Climate Crash; Lessons for Climate Change in the 2008 Recession

Henry M. Paulson Jr., June 21, 2014 (NY Times)

“THERE is a time for weighing evidence and a time for acting. And if there’s one thing I’ve learned throughout my work in finance, government and conservation, it is to act before problems become too big to manage. For too many years, we failed to rein in the excesses building up in the nation’s financial markets. When the credit bubble burst in 2008, the damage was devastating. Millions suffered. Many still do.

“We’re making the same mistake today with climate change. We’re staring down a climate bubble that poses enormous risks to both our environment and economy. The warning signs are clear and growing more urgent as the risks go unchecked.

“This is a crisis we can’t afford to ignore. I feel as if I’m watching as we fly in slow motion on a collision course toward a giant mountain. We can see the crash coming, and yet we’re sitting on our hands rather than altering course.

“We need to act now, even though there is much disagreement, including from members of my own Republican Party, on how to address this issue while remaining economically competitive. They’re right to consider the economic implications. But we must not lose sight of the profound economic risks of doing nothing…” click here for more

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THE PAULSON PIECE, PART 2

The Coming Climate Crash; Lessons for Climate Change in the 2008 Recession

Henry M. Paulson Jr., June 21, 2014 (NY Times)

“The solution can be a fundamentally conservative one that will empower the marketplace to find the most efficient response. We can do this by putting a price on emissions of carbon dioxide — a carbon tax. Few in the United States now pay to emit this potent greenhouse gas into the atmosphere we all share. Putting a price on emissions will create incentives to develop new, cleaner energy technologies.

“It’s true that the United States can’t solve this problem alone. But we’re not going to be able to persuade other big carbon polluters to take the urgent action that’s needed if we’re not doing everything we can do to slow our carbon emissions and mitigate our risks.

“I was secretary of the Treasury when the credit bubble burst, so I think it’s fair to say that I know a little bit about risk, assessing outcomes and problem-solving. Looking back at the dark days of the financial crisis in 2008, it is easy to see the similarities between the financial crisis and the climate challenge we now face.

“We are building up excesses (debt in 2008, greenhouse gas emissions that are trapping heat now). Our government policies are flawed (incentivizing us to borrow too much to finance homes then, and encouraging the overuse of carbon-based fuels now). Our experts (financial experts then, climate scientists now) try to understand what they see and to model possible futures. And the outsize risks have the potential to be tremendously damaging (to a globalized economy then, and the global climate now).

“Back then, we narrowly avoided an economic catastrophe at the last minute by rescuing a collapsing financial system through government action. But climate change is a more intractable problem. The carbon dioxide we’re sending into the atmosphere remains there for centuries, heating up the planet.

“That means the decisions we’re making today — to continue along a path that’s almost entirely carbon-dependent — are locking us in for long- term consequences that we will not be able change but only adapt to, at enormous cost. To protect New York City from rising seas and storm surges is expected to cost at least $20 billion initially, and eventually far more. And that’s just one coastal city…” click here for more

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THE PAULSON PIECE, PART 3

The Coming Climate Crash; Lessons for Climate Change in the 2008 Recession

Henry M. Paulson Jr., June 21, 2014 (NY Times)

“…When I worry about risks, I worry about the biggest ones, particularly those that are difficult to predict — the ones I call small but deep holes. While odds are you will avoid them, if you do fall in one, it’s a long way down and nearly impossible to claw your way out.

“Scientists have identified a number of these holes — potential thresholds that, once crossed, could cause sweeping, irreversible changes. They don’t know exactly when we would reach them. But they know we should do everything we can to avoid them.

“Already, observations are catching up with years of scientific models, and the trends are not in our favor…[In] May, two separate studies discovered that one of the biggest thresholds has already been reached. The West Antarctic ice sheet has begun to melt, a process that scientists estimate may take centuries but that could eventually raise sea levels by as much as 14 feet. Now that this process has begun, there is nothing we can do to undo the underlying dynamics, which scientists say are “baked in.” And 10 years from now, will other thresholds be crossed that scientists are only now contemplating? It is true that there is uncertainty about the timing and magnitude of these risks and many others. But those who claim the science is unsettled or action is too costly are simply trying to ignore the problem. We must see the bigger picture.

“The nature of a crisis is its unpredictability. And as we all witnessed during the financial crisis, a chain reaction of cascading failures ensued from one intertwined part of the system to the next. It’s easy to see a single part in motion. It’s not so easy to calculate the resulting domino effect.

“That sort of contagion nearly took down the global financial system.

“With that experience indelibly affecting my perspective, viewing climate change in terms of risk assessment and risk management makes clear to me that taking a cautiously conservative stance — that is, waiting for more information before acting — is actually taking a very radical risk. We’ll never know enough to resolve all of the uncertainties. But we know enough to recognize that we must act now…” click here for more

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THE PAULSON PIECE, SOLUTIONS

The Coming Climate Crash; Lessons for Climate Change in the 2008 Recession

Henry M. Paulson Jr., June 21, 2014 (NY Times)

“…I’m a businessman, not a climatologist. But I’ve spent a considerable amount of time with climate scientists and economists who have devoted their careers to this issue. There is virtually no debate among them that the planet is warming and that the burning of fossil fuels is largely responsible.

“Farseeing business leaders are already involved in this issue…We need to craft national policy that uses market forces to provide incentives for the technological advances required to address climate change. As I’ve said, we can do this by placing a tax on carbon dioxide emissions. Many respected economists, of all ideological persuasions, support this approach. We can debate the appropriate pricing and policy design and how to use the money generated. But a price on carbon would change the behavior of both individuals and businesses. At the same time, all fossil fuel — and renewable energy — subsidies should be phased out.

“Renewable energy can outcompete dirty fuels once pollution costs are accounted for.

“Some members of my political party worry that pricing carbon is a “big government” intervention. In fact, it will reduce the role of government, which, on our present course, increasingly will be called on to help communities and regions affected by climate-related disasters like floods, drought-related crop failures and extreme weather like tornadoes, hurricanes and other violent storms. We’ll all be paying those costs. Not once, but many times over.

“This is already happening, with taxpayer dollars rebuilding homes damaged by Hurricane Sandy and the deadly Oklahoma tornadoes. This is a proper role of government. But our failure to act on the underlying problem is deeply misguided, financially and logically.

“In a future with more severe storms, deeper droughts, longer fire seasons and rising seas that imperil coastal cities, public funding to pay for adaptations and disaster relief will add significantly to our fiscal deficit and threaten our long-term economic security. So it is perverse that those who want limited government and rail against bailouts would put the economy at risk by ignoring climate change.

“This is short-termism…We would be fools to wait…When you run a company, you want to hand it off in better shape than you found it. In the same way, just as we shouldn’t leave our children or grandchildren with mountains of national debt and unsustainable entitlement programs, we shouldn’t leave them with the economic and environmental costs of climate change. Republicans must not shrink from this issue. Risk management is a conservative principle, as is preserving our natural environment for future generations. We are, after all, the party of Teddy Roosevelt.

“THIS problem can’t be solved without strong leadership from the developing world. The key is cooperation between the United States and China — the two biggest economies, the two biggest emitters of carbon dioxide and the two biggest consumers of energy.

“When it comes to developing new technologies, no country can innovate like America. And no country can test new technologies and roll them out at scale quicker than China. The two nations must come together on climate…

“A tax on carbon emissions will unleash a wave of innovation to develop technologies, lower the costs of clean energy and create jobs as we and other nations develop new energy products and infrastructure. This would strengthen national security by reducing the world’s dependence on governments like Russia and Iran.

“Climate change is the challenge of our time. Each of us must recognize that the risks are personal. We’ve seen and felt the costs of underestimating the financial bubble. Let’s not ignore the climate bubble.” click here for more

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TODAY’S STUDY: NEW ENERGY FOR A WORLD FIGHTING CLIMATE CHANGE

Climate Change: Implications for the Energy Sector (Key Findings from the Intergovernmental Panel on Climate Change Fifth Assessment Report)

June 2014 (World Energy Council and the University of Cambridge)

The Physical science of Climate Change

Rising temperatures:

The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) concludes that climate change is unequivocal, and that human activities, particularly emissions of carbon dioxide, are very likely to be the dominant cause. Changes are observed in all geographical regions: the atmosphere and oceans are warming, the extent and volume of snow and ice are diminishing, sea levels are rising and weather patterns are changing.

Projections:

Computer models of the climate used by the IPCC indicate that changes will continue under a range of possible greenhouse gas emission scenarios over the 21st century. If emissions continue to rise at the current rate, impacts by the end of this century are projected to include a global average temperature 2.6–4.8 degrees Celsius (°C) higher than present, and sea levels 0.45–0.82 metres higher than present.

To prevent the most severe impacts of climate change, parties to the UN Framework Convention on Climate Change (UNFCCC) agreed a target of keeping the rise in average global temperature since pre-industrial times below 2°C, and to consider lowering the target to 1.5°C in the near future. The first instalment of AR5 in 2013 (Working Group I on the physical science basis of climate change) concluded that by 2011, we had already emitted about two-thirds of the maximum cumulative amount of carbon dioxide that we can emit if we are to have a better than two-thirds chance of meeting the 2°C target.

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Impact of past emissions:

Even if emissions are stopped immediately, temperatures will remain elevated for centuries due to the effect of greenhouse gases from past human emissions already present in the atmosphere. Limiting temperature rise will require substantial and sustained reductions of greenhouse gas emissions.

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Key Findings

energy demand is increasing globally, causing greenhouse gas (GHG) emissions from the energy sector also to increase. The trend is set to continue, driven primarily by economic growth and the rising population. In recent years the long-term trend of gradual decarbonisation of energy has reversed due to an increase in coal burning.

Climate change presents increasing challenges for energy production and transmission. A progressive temperature increase, an increasing number and severity of extreme weather events and changing precipitation patterns will affect energy production and delivery. The supply of fossil fuels, and thermal and hydropower generation and transmission, will also be affected. However, adaptation options exist. significant cuts in GHG emissions from energy can be achieved through a variety of measures. These include cutting emissions from fossil fuel extraction and conversion, switching to lower-carbon fuels (for example from coal to gas), improving energy efficiency in transmission and distribution, increasing use of renewable and nuclear generation, introduction of carbon capture and storage (CCS), and reducing final energy demand.

strong global political action on climate change would have major implications for the energy sector. Stabilisation of emissions at levels compatible with the internationally agreed 2°C temperature target will mean a fundamental transformation of the energy industry worldwide in the next few decades, on a pathway to complete decarbonisation. incentivising investment in low-carbon technologies will be a key challenge for governments and regulators to achieve carbon reduction targets. Reducing GHG emissions also brings important co-benefits such as improved health and employment, but supply-side mitigation measures also carry risks.

The energy industry is both a major contributor to climate change and a sector that climate change will disrupt. Over the coming decades, the energy sector will be affected by global warming on multiple levels, and by policy responses to climate change. The stakes are high: without mitigation policies, the global average temperature is likely to rise by 2.6–4.8°C by 2100 from pre-industrial levels.

In the absence of strong mitigation policies, economic growth and the rising global population will continue to drive energy demand upwards, and hence GHG emissions will also rise. Climate change itself may also increase energy use due to greater demand for cooling.

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The means and infrastructure to produce and transport energy will be adversely impacted by climate change. The oil and gas industry is likely to suffer from increased disruption and production shutdowns due to extreme weather events affecting both offshore and onshore facilities. Power plants, especially those in coastal areas, will be affected by extreme weather events and rising sea levels. Critical energy transport infrastructure is at risk, with oil and gas pipelines in coastal areas affected by rising sea levels and those in cold climates affected by thawing permafrost.

Electricity grids will be impacted by storms, and the rise in global temperature may affect electricity generation including thermal and hydroelectric stations in some locations. Weather changes may also affect bioenergy crops. In general, the industry has options for adapting to climatic changes, but costs are likely to be incurred.

The energy sector is the largest contributor to global GHG emissions. In 2010, 35% of direct GHG emissions came from energy production. In recent years the long-term trend of gradual decarbonisation of energy has reversed. From 2000 to 2010, the growth in energy sector emissions outpaced the growth in overall emissions by around 1% per year. This was due to the increasing share of coal in the energy mix. From annual emissions of 30 gigatonnes (Gt) of carbon dioxide (CO2) in 2010, projections indicate that in the absence of policies to constrain emissions, the emissions associated with fossil fuel use, including the energy supply sector but also energy use in transport, industry and buildings would contribute 55–70 GtCO2 per year by 2050. To reduce emissions to levels commensurate with the internationally agreed goal of keeping the temperature increase since pre-industrial times below 2°C, the share of low-carbon electricity generation by 2050 will need to triple or quadruple. Use of fossil fuels without carbon capture would virtually disappear by 2100 at the latest. The energy sector would be completely decarbonised, and it is likely that technologies able to withdraw CO2 from the atmosphere would need to be deployed. Bioenergy with carbon capture and storage is one such technology (BECCS).

Replacing existing coal-fired heat and/or power plants by highly efficient natural gas combined cycle (NGCC) power plants or combined heat and power (CHP) plants can reduce near-term emissions (provided that fugitive methane release is controlled) and be a ‘bridging technology’ to a low-carbon economy. Increased use of CHP plants can reduce emissions. CCS, nuclear power and renewables provide low-carbon electricity, while increasing energy efficiency and reducing final energy demand will reduce the amount of supply-side mitigation needed. In 2012, more than half of the net investment in the electricity sector was in low-carbon technologies.

Nevertheless, a variety of barriers and risks to accelerated investment exist, including cost. Additional supply-side investments required to meet the 2°C target are estimated at USD 190–900 billion per year on average up to 2050. Much of this investment would yield co-benefits such as reduced air and water pollution, and increased local employment. But supply side mitigation typically also carries risks.

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Impacts of Climate Change

Three climate-change phenomena will have a particular impact on the energy sector: global warming, changing regional weather patterns (including hydrological patterns) and an increase in extreme weather events. Not only will these phenomena affect energy demand, in some regions they will also affect the entire spectrum of energy production and transmission. While most climate change impacts are likely to be negative, there could be some positive impacts such as lower energy demand in cold climates.

Rising temperatures coupled with a growing world population and economic growth will drive an increase in overall demand for energy. Rising income levels in poorer countries in warm climates are likely to lead to increased use of air-conditioning. Global energy demand for residential air-conditioning in summer is projected to increase rapidly from nearly 300 TWh in 2000, to about 4000 TWh in 2050. Much of this growth is due to increasing income in emerging market countries, but some is due to climate change. Colder, richer countries will see energy demand for heating fall, but could still see overall energy use increase.

Although thermal power plants (currently providing about 80% of global electricity) are designed to operate under diverse climatic conditions, they will be affected by the decreasing efficiency of thermal conversion as a result of rising ambient temperatures. Also, in many regions, decreasing volumes of water available for cooling and increasing water temperatures could lead to reduced power operations, operation at reduced capacity or even temporary shutdowns.

Extreme weather events pose a major threat to all power plants but particularly to nuclear plants, where they could disrupt the functioning of critical equipment and processes that are indispensable to safe operation including reactor vessels, cooling equipment, control instruments and back-up generators.

Changing regional weather patterns are likely to affect the hydrologic cycle that underpins hydropower generation. In some regions, a decline in rainfall levels and a rise in temperature, leading to increased water loss, could result in reduced or more intermittent ability to generate electricity.

Although projections contain large uncertainties, hydropower capacity in the Zambezi river basin in Africa may fall by as much as 10% by 2030, and 35% by 2050. On the other hand, hydropower capacity in Asia could increase.

Changing weather patterns and extreme weather events present challenges to solar and wind energy. An anticipated increase in cloudiness in some regions would affect solar technologies, while an increase in the number and severity of storms could damage equipment. Global warming and changing weather patterns are likely to adversely impact agricultural yields, with a knock-on effect on the production and availability of biomass for energy generation. While there might be some benefits in temperate climates, the reduction in yields in tropical areas is more likely than not to exceed 5% by 2050. In some rainy regions, open pits in the coal industry are likely to be impacted by increasing rainfall leading to floods and landslides.

Climate and weather related hazards in the oil and gas sector include tropical cyclones with potentially severe effects on offshore platforms and onshore infrastructure, leading to more frequent production interruptions. However, the decline in Arctic sea ice could lead to the opening up of new areas for oil and gas exploration, potentially increasing global oil and gas reserves.

Energy transmission infrastructure, such as pipelines and power lines, is also likely to be affected by higher temperatures and extreme weather events. Pipelines are at risk from sea-level rise in coastal regions, thawing permafrost in cold regions, floods and landslides triggered by heavy rainfall, and bushfires caused by heat waves or extreme temperatures in hot regions. Extreme weather events, especially strong wind, are projected to affect power lines.

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Resilience

There are various options by which the energy sector can improve its resilience to climate change.

A number of technological improvements are available for thermal power plants which, if implemented, will bring efficiency gains that more than compensate for losses due to higher ambient temperatures. Preventative and protective measures for nuclear power plants include technical and engineering solutions and adjusting operation to extreme conditions, including reducing capacity or shutting down plants. Weather resistance of solar technologies and wind power turbines continues to increase.

Coal mining companies can improve drainage and run-off for on-site coal storage, as well as implementing changes in coal handling due to the increased moisture content of coal. Pipeline operators may be forced to follow new land zoning codes and to implement risk-based design and construction standards for new pipelines, and structural upgrades to existing infrastructure.

Technical standards for power transmission lines are likely to be amended to force grid operators to implement appropriate adaptation measures, including in some cases re-routing lines away from high-risk areas.

Authorities can plan for evolving demand needs for heating and cooling by assessing the impact on the fuel mix. Heating often involves direct burning of fossil fuels, whereas cooling is generally electrically powered. More demand for cooling and less for heating will create a downward pressure on direct fossil fuel use, but an upward pressure on demand for electricity.

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Mitigation Options

As the sector producing the largest share of GHG emissions, the energy sector would be substantially affected by policies aimed at meeting the internationally agreed 2°C target for global warming. A number of mature options exist that can, if scaled up, result in substantial mitigation of the sector’s GHG emissions. However, the scale of the challenge is considerable. Pathways compatible with the 2°C target typically envisage achieving virtual decarbonisation of the energy supply at some point between 2050 and the end of the century. It is likely that ‘negative emissions’ – technologies that absorb CO2 from the atmosphere – will also be needed.

Options for mitigation include:

• Cutting emissions from fossil fuel extraction and conversion

• Switching to lower-carbon fuels, for example from coal to gas

• Improving energy efficiency in transmission and distribution

• Increasing use of renewable energy technologies

• Increasing use of nuclear energy

• Introduction of carbon capture and storage (CCS), and an extension into CCS plants that use bioenergy crops (BECCS) as an approach to achieving ‘negative emissions’

• Reducing final energy demand.

Fuel extraction and Conversion…Fuel switching…Increasing efficiency…Renewables…Nuclear energy…CCS and bioenergy…Reducing final energy demand…Co-benefits and risks…Policy…

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Conclusion

Climate change will affect the entire energy sector, through impacts and through policy. While the cost of mitigating emissions across all sectors could reduce annual consumption growth by 0.04–0.14%, the scale of the low-carbon transition and the opportunities for investment are likely to be larger in the energy sector than in others. Additional investments required in the energy system in order to keep the temperature increase since pre-industrial times below 2°C are estimated to be USD 190–900 billion per year on the supply-side alone, although this investment could realise important co-benefits for economies as a whole. However, infrastructure tends to be used for at least 30 years once built; so decisions made in the next couple of decades will be crucial in deciding whether the energy sector leads the way towards or away from a 2°C future.

Scenarios project that a fundamental transformation will be necessary if governments are to meet the globally agreed 2°C target. Generally, these scenarios envisage three parallel processes: decarbonisation of the electricity supply, expansion of the electricity supply into areas such as home heating and transport that are currently fuelled in other ways, and reduction in final energy demand. Much of the incremental investment will be in developing countries where demand is growing at a faster rate than in developed countries. The additional capital would be partly offset by the lower operating costs of many low-GHG energy supply sources. For government and regulators, a key challenge will be to ensure a price of carbon that incentivises extra investment in low-carbon technologies, continued investment in research and development, and an attractive fiscal and regulatory framework.

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QUICK NEWS, June 26: TEXAS PROVES MORE WIRES MEANS MORE NEW ENERGY; DUKE’S BIGGEST SUN IN THE EAST FOR GWU, AU; WHAT TO WATCH IN FUEL CELLS

TEXAS PROVES MORE WIRES MEANS MORE NEW ENERGY Fewer wind curtailments and negative power prices seen in Texas after major grid expansion

June 24, 2014 (U.S. Energy Information Administration)

Texas wind power reached a new instantaneous peak output of 10,296 megawatts on March 26, 29% of total electricity, after setting new records twice in the previous week and, according to grid operator Electric Reliability Council of Texas (ERCOT), more new records are expected as Texas’s 12,000-plus megawatt wind capacity continues to grow…Texas wind’s record-setting performance is partially due to the completion of the Competitive Renewable Energy Zones (CREZ) transmission expansion specifically designed to deliver West Texas and Panhandle winds to ERCOT load centers in Dallas, Ft. Worth, Austin, and San Antonio and to reduce wind curtailments…Curtailment dropped steadily as the 3,500 mile CREZ transmission system build out advanced and wind-related negative electricity pricing decreased as the new transmission reduced oversupply problems by taking wind energy-generated electricity to a wider range of demand areas…

Negative pricing occurs when there is more electricity supply than demand and wind generators become willing to accept below zero prices for their output because they have no fuel costs and can get a $0.023 per kilowatt-hour production tax credit for the electricity the grid takes…A perhaps more important factor in Texas wind’s new records is that wind’s vital Production Tax Credit was restructured last year to allow eligibility to projects that commenced construction during 2013 instead of only to those that went online during the year, resulting in more than 7,000 megawatts of in-construction capacity that began coming online this year... click here for more

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DUKE’S BIGGEST SUN IN THE EAST FOR GWU, AU George Washington University, American University make deal to buy solar power farms

June 24, 2014 (AP via ABC News)

Duke Energy Renewables has contracted to supply solar from its Capital Partners Solar Project solar power plant to be built in North Carolina to George Washington University, American University and the George Washington University Hospital…Duke will break ground on the 52 megawatt project at the first of three sites this summer, build in three stages, bring the first 20 megawatts online this year and add the final 32 megawatts to be fully operational in 2015…The 20 year contract between Duke and the universities is the biggest solar power purchase agreement (PPA) with a non-utility off-taker in the U.S. and the PV project is the biggest east of the Mississippi River, according to the Solar Energy Industries Association…Duke won the PPAs in a competitive bidding process that included 28 wind and solar developers…University officials expect the move to solar to save “millions of dollars” as the cost of conventional generation rises… click here for more

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WHAT TO WATCH IN FUEL CELLS The Fuel Cell and Hydrogen Industries: 10 Trends to Watch

2Q 2014 (Navigant Research)

“…Over the past 18 months, there has been a real divergence in the fortunes of various fuel cell sectors. The stationary sector has seen 2 years of strong growth while some sectors, such as portable, have continued to struggle…[or] been in a holding pattern…[T]he fuel cell vehicle (FCV) market is poised for the launch of commercial vehicles, spurring a flurry of investment in hydrogen infrastructure…[The key trends are]:

1-Fuel cells back on the radar of the skeptical U.S. media

2-Stationary sector continues to lead the fuel cell industry

3-Investors cautiously coming off the fence on fuel cells

4-FCVs continue to be compared to plug-in electric vehicles (PEVs)

5-Hydrogen infrastructure stakeholders must prove they can build stations

6-[Combined Heat and Power (CHP)] is on path to surpass prime power stationary fuel cells

7-Fuel cells face stiff competition from engine- or turbine-based CHP 8-Booming North American microgrid market offers opportunity for fuel cells

9-Power-to-gas concept will be proven in Europe 10-Portable fuel cells still struggling to hit the right value proposition…” click here for more

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TODAY’S STUDY: WHY THOSE WIND TURBINES AREN’T TURNING

Wind and Solar Energy Curtailment: Experience and Practices in the United States

Lori Bird, Jaquelin Cochran, and Xi Wang, March 2014 (National Renewable Energy Laboratory)

Executive Summary

Curtailment is a reduction in the output of a generator from what it could otherwise produce given available resources, typically on an involuntary basis. Curtailment of generation has been a normal occurrence since the beginning of the electric power industry. However, owners of wind and solar generation, which have no fuel costs, are concerned about the impacts of curtailment on project economics. Operator-induced curtailment typically occurs because of transmission congestion or lack of transmission access, but it can occur for a variety of other reasons, such as excess generation during low load periods, voltage, or interconnection issues. Market-based protocols that dispatch generation based on economics can also result in wind and solar energy plants generating less than what they could potentially produce.

This report examines U.S. curtailment practices regarding wind and solar generation, with a particular emphasis on utilities in the western states. The information presented here is based on a series of interviews conducted with utilities, system operators, wind energy developers, and other stakeholders. The report provides case studies of curtailment experience and examines the reasons for curtailment, procedures, compensation, and practices that can minimize curtailment.

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Key findings include:

• In the largest markets for wind power, the amount of curtailment appears to be declining even as the amount of wind power on the system increases. Curtailment levels have generally been 4% or less of wind generation in regions where curtailment has occurred. Many utilities in the western states report negligible levels of curtailment. The most common reasons for curtailment are insufficient transmission and local congestion and excessive supply during low load periods.

• Definitions of curtailment and data availability vary. Understanding curtailment levels can be complicated by relatively new market-based protocols or programs that dispatch wind down or limit wind generation to schedules and the lack of uniformity in data collection.

• Compensation and contract terms are changing as curtailment becomes of greater concern to solar and wind plant owners. Increasingly there are negotiated contract provisions addressing use of curtailment hours and there is greater explicit sharing of risk between the generator and off-taker.

• Automation can reduce curtailment levels. Manual curtailment processes can extend curtailment periods because of the time needed for implementation and hesitancy to release units from curtailment orders.

• Market solutions that base dispatch levels on economics offer the advantages of creating transparency and automation in curtailment procedures, which apply equally to all generators.

• Curtailed wind and solar resources may provide ancillary services to aid in system operations.

• A variety of solutions is being used to reduce curtailments: transmission expansion and interconnection upgrades; operational changes such as forecasting and increased automation of signaling; and better management of reserves and generation.

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Introduction

Curtailment of variable renewable generation, particularly wind and solar energy, is becoming more widespread as wind and solar energy development expands across the country and penetrations increase. Curtailment can affect the revenue of wind and solar energy projects.

These impacts are specific to each balancing area due to differences in grid characteristics, operating practices, and other factors such as weather.

In this paper, we define curtailment as a reduction in the output of a generator from what it could otherwise produce given available resources (e.g., wind or sunlight), typically on an involuntary basis. Curtailments can result when operators or utilities command wind and solar generators to reduce output to minimize transmission congestion or otherwise manage the system or achieve the optimal mix of resources. Curtailment of wind and solar resources typically occurs because of transmission congestion or lack of transmission access, but it can also occur for reasons such as excess generation during low load periods that could cause baseload generators to reach minimum generation thresholds, because of voltage or interconnection issues, or to maintain frequency requirements, particularly for small, isolated grids. Curtailment is one among many tools to maintain system energy balance, which can also include grid capacity, hydropower and thermal generation, demand response, storage, and institutional changes. Deciding which method to use is primarily a matter of economics and operational practice.

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“Curtailment” today does not necessarily mean what it did in the early 2000s. Two sea changes in the electric sector have shaped curtailment practices since that time: the utility-scale deployment of wind power, which has no fuel cost, and the evolution of wholesale power markets. These simultaneous changes have led to new operational challenges but have also expanded the array of market-based tools for addressing them.

Practices vary significantly by region and market design. In places with centrally-organized wholesale power markets and experience with wind power, manual wind energy curtailment processes are increasingly being replaced by transparent offer-based market mechanisms that base dispatch on economics. Market protocols that dispatch generation based on economics can also result in renewable energy plants generating less than what they could potentially produce with available wind or sunlight. This is often referred to by grid operators by other terms, such as “downward dispatch.” In places served primarily by vertically integrated utilities, power purchase agreements (PPAs) between the utility and the wind developer increasingly contain financial provisions for curtailment contingencies.

This report delineates several types of practices under the broad rubric of curtailment done for wind or solar generation. Some reductions in output are determined by how a wind operator values dispatch versus non-dispatch. Other curtailments of wind are determined by the grid operator in response to potential reliability events. Still other curtailments result from overdevelopment of wind power in transmission-constrained areas. Responses to all types of curtailment largely reflect the operating context, including whether the wind power is part of an centrally-organized wholesale market, or whether it is in a balancing authority area operated by a vertically integrated utility.

Dispatch below maximum output (curtailment) can be more of an issue for wind and solar generators than it is for fossil generation units because of differences in their cost structures. The economics of wind and solar generation depend on the ability to generate electricity whenever there is sufficient sunlight or wind to power their facilities. Because wind and solar generators have substantial capital costs but no fuel costs (i.e., minimal variable costs), maximizing output improves their ability to recover capital costs. In contrast, fossil generators have higher variable costs, such as fuel costs. Avoiding these costs can, depending on the economics of a specific generator, to some degree reduce the financial impact of curtailment, especially if the generator's capital costs are included in a utility's rate base.

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Ascertaining the level of curtailment of wind and solar generation and its impacts is challenging. Often system operators or utilities do not track it or make data publicly available, and there are differences in terminology as well. Manual curtailment processes for wind have been replaced by economic dispatch protocols in a number of regions, and under the new protocols, dispatch below maximum output is typically not referred to as curtailment. In addition, energy lost due to line outages, and limits placed on deviations from schedule can all reduce wind generator’s production; some operators call these actions curtailment while others do not.

This report examines curtailment practices for wind and solar energy in the United States, with a particular emphasis on utilities in the western states. Much of the experience documented in this report pertains to curtailment of wind power, which has reached higher penetrations of bulk system power, although solar curtailment is included where information is available.

This report builds on earlier reviews of domestic curtailment experience by Rogers et al. (2010) and Fink et al. (2009) and a recent review of international practices by Lew et al. (2013). The information presented here is based on a series of interviews conducted with utilities, system operators, wind energy developers and owners, and non-governmental organizations as well as other available data sources. This review was conducted to better understand the diversity of practices in place and the magnitude of curtailment that has been occurring. The report provides case studies of curtailment experience and examines the reasons for curtailment, curtailment procedures, compensation, and practices that can minimize curtailment of wind and solar.

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Overview: Levels of Curtailment in the United States

Curtailment levels, where curtailment has occurred, are often in the range of 1% to 4% of wind generation, but higher levels have been reported by the Electric Reliability Council of Texas (ERCOT) in past years, as can be seen in Figure 1.

However, the levels of wind curtailment experienced to date in the United States differ substantially by region and utility service territory, as discussed in Section 3. In many regions, curtailment is very low and not even tracked. Table 1 provides a summary of curtailment levels and causes for all of the utilities and grid operators interviewed for this study. Further discussion of the reason for curtailments is included in Section 3. Table A-1 in Appendix A summarizes experiences with wind and solar energy curtailment from all of the utilities and grid operators interviewed, including utilities that reported relatively low levels of curtailment…

Conclusions

While a greater number of regions are experiencing some form of curtailment of wind and solar resources, the relative magnitude of curtailment appears to be declining in the largest markets for wind power even as the amount of wind power on the system increases. New transmission capacity and better operating practices, such as greater automation and the use of forecasting and other operational practices, are now resolving challenges for grid operators, often circumventing the need for curtailment. As penetrations of wind and solar energy increase, curtailment practices and the use of strategies to mitigate the potential for curtailment may become increasingly important and may impact wind and solar energy project economics. Nevertheless, as wind and solar energy penetrations increase, there may come a time when changes in operating protocols would not lead to reduced curtailments, and rather that curtailment volumes could rise as a fraction of total wind and solar generation.

Curtailment levels have generally been 4% or less of wind energy generation in regions where curtailment has occurred. A notable exception is ERCOT, where curtailment levels reached 17% in one year, primarily because wind generation came online ahead of transmission capacity.

These levels have since receded to less than 2%. Many utilities in the western states report negligible levels of curtailment. The most common reasons for curtailment are insufficient transmission and local congestion, and excessive supply during low load periods. One challenge to determining curtailment levels is that data are not uniformly collected.

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Definitions of curtailment vary. Understanding curtailment levels can be complicated by relatively newly implemented market-based protocols or programs that limit wind generation to schedules. Now that economic dispatch is being used in several areas, wind generators can be dispatched down based on market prices, but this reduction of output is not characterized as curtailment. In some cases, wind generators are not able to exceed scheduled levels—a process that is referred to in the BPA balancing area as limiting output rather than curtailment.

Curtailment order varies and is often based on plant economics or ability to alleviate local congestion. For curtailments that are needed to address balancing or system operations, the most expensive generators are often curtailed first. For wind projects, one consideration is whether the project utilizes the federal PTC or ITC. Generators reliant on the PTC, which is provided based on project output, face greater financial impacts from curtailment (the value of the PTC as well as the energy) than wind generators that received the upfront ITC. To address local congestion issues, curtailment is often applied equitably across generators that are most able to alleviate congestion. Hawaii provides preference to projects based on the order that they were installed (i.e., curtailing the most recently installed resources first), which limits the financial impacts and risks of curtailment for existing renewable energy facilities.

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Compensation and contract terms are changing for curtailment. Contracts between generators and off-takers have in some cases included provisions whereby the off-taker will compensate for curtailment for reasons such as congestion, scheduled maintenance, and operator errors, but typically not for curtailment ordered by other entities. However, contracts are increasingly reflecting a negotiated number of annual hours in which curtailments are not compensated, despite the cause, and there is greater sharing of risk between the generator and off-taker. In some cases, when new curtailment procedures are adopted, the need to renegotiate contract language has posed implementation challenges. In wholesale power markets, the grid operator sometimes compensates if it calls for units to deviate from initial dispatch orders.

Automation can reduce curtailment levels. Manual curtailment processes for wind have been found to extend curtailment periods because of the time required to implement curtailment and hesitancy to release units from curtailment orders. Automatic communication procedures can speed the implementation of curtailment orders and reduce overall curtailment time.

Market solutions that base dispatch levels on economics offer the advantages of creating transparency and efficiency in curtailment procedures, which apply equally to all generation sources. Programs like the MISO DIR utilize economic dispatch to determine which units will generate at a given time. During periods of oversupply, the use of negative pricing to determine dispatch order can eliminate the need for manual curtailments. Some wind developers have expressed a preference of the market-based dispatch framework because it reduces market distortions and allows wind generators to participate alongside conventional generators.

The use of market-based approaches with their associated automation can also minimize curtailment by improving operational efficiency and reducing the burden on grid operators of implementing manual processes.

Curtailed wind resources can provide ancillary services to aide in system operations. PSCO uses curtailed wind resources to provide both up and down regulation reserves for the balancing area. Wind turbines can provide quick response to signals, which can be valuable for the system. MISO assessed this and found it was economically viable only 2% of the time, however. ERCOT requires all wind turbines that can be retrofitted with governor response to do so in order to provide primary frequency response if they are curtailed.

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Transmission expansion and interconnection upgrades can be one of the most direct ways to reduce curtailments. ERCOT’s expansion of transmission in recent years through CREZ has alleviated wind generator curtailments. A key challenge is that renewable energy projects can be built much more rapidly than transmission lines. The CREZ program identified the need for transmission to particular regions to facilitate wind energy expansion. SPP is building new transmission capacity that is expected to alleviate current curtailment levels, while MISO is pursuing multi-value transmission projects to move wind to load centers and more robust parts of the grid.

Forecasting can decrease uncertainty associated with wind and solar resources, reducing the need for curtailments due to unexpected changes. Improved forecasting can enable utilities or grid operators to turn down conventional resources when sufficient wind generation is predicted and to reduce curtailment from oversupply. Improved forecasting can also reduce curtailments related to ramping. Wind forecasting can provide generators better information and enable them to participate more fully in the day-ahead market. Improved data on wind profiles may help grid operators provide more precise not-to-exceed instructions, enabling increased wind generation output. Grid operators could also improve visibility of distributed solar, which appears to grid operators as reduced load, to help understand system changes that can influence unit commitment and balancing to minimize curtailments.

Firming resources can decrease curtailments and increase financial certainty for generators, but they are not necessarily the most cost-effective system-wide solution. Iberdrola in BPA has found it more cost-effective to balance its own resources than it is to pay integration charges and be exposed to uncompensated curtailments under DSO 216. Nevertheless, developer-specific balancing, through options such as storage and natural gas, may likely be less cost-effective at a system-wide level than it would be for the utility or grid operator to adopt operating practices that minimize the need to curtail, such as dynamic reserves, negative pricing, and improved forecasting.

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