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A Renewed Push from the White House on Grid Modernization

2011-06-13T21:24:16Z

Samir Succar, Staff Scientist, Washington, DC

At a White House event today, the administration released a new report that frames the modernization of the US power grid and launches a number of public and private initiatives including new outreach efforts, partnerships and loan programs. As today’s speakers made clear, we will modernize our aging grid infrastructure; the only question is whether we'll make the most effective investments that foster innovation, facilitate renewables integration and drive the deployment of energy efficiency.

Both the report and the White House panel discussion that took place today cover a lot of ground. Secretary Chu and others described in some detail how demand response, electrical energy storage and thermal energy storage could help us get a large fraction of our electricity from renewable sources. The panel also discussed how siting large, high voltage direct current (HVDC) transmission lines rather than a “spaghetti bowl” of smaller lines could, in some cases, help minimize the land impacts of transmission development and improve the efficiency of the grid by reducing line losses. Other topics included DOE’s role as convener to facilitate investment in these innovative technologies, the flexibility needed at the state level to implement reforms and the importance of security and data privacy.

Both panels repeatedly came back to three central points. First, grid modernization is about the integration of distribution, generation and transmission. It is more than advanced metering infrastructure, information technology and smart grid; we need to take a holistic approach to addressing the challenges that lie ahead. Second, while the costs of grid upgrades are well known, their benefits are often diffuse. We need to deploy new technologies with targeted end goals in mind rather than taking a “blank check” approach. Finally, the key to putting these pieces together, getting the greatest benefit out of them, and building support for these technologies is keeping an “eyes-wide-open” approach to understanding costs and benefits. This means looking across regions, realizing the benefits of demand-side resources and planning ahead to anticipate future grid needs.

The administration’s A Policy Framework for the 21st Century Grid outlines a path forward built around four pillars: enabling cost-effective investment, unlocking innovation, empowering consumers and securing the grid. The document also describes the DOE’s work on grid innovation and highlights many of the Smart Grid projects funded thus far through the recovery act. A key focus is the need for cooperation among federal government entities, state regulators, the private sector and consumers. In closing, the facilitator framed today as a “revival event” rather than a “victory lap,” underscoring the long road ahead.

Missing from the conversation however, was a discussion of the need to strike the right balance between this broad-based cooperation and the extraordinary urgency required to address climate change. We need the long-term regional plans to help guide our path forward on energy. The more we can work together to define best practices and establish a common vision for future investment with broad stakeholder support, the better. Nevertheless, if we are to meet the carbon abatement goals that the science tells us are necessary we cannot afford to move forward at a snail's pace. This important groundwork must be undertaken while keeping mind the enormous scale of what will be required to get our planet back on a sustainable path.

3 Reasons Why We Don't Have to Choose Between our Health and a Reliable Power Grid: Facilitating a Transition Away From Dirty Coal

2010-08-19T14:02:00Z

Samir Succar, Staff Scientist, Washington, DC

The promise of new clean air rules from EPA will go a long way toward eliminating emissions from the oldest, dirtiest power plants that pollute our air and threaten our health. Despite some spurious claims from industry groups, it’s abundantly clear that we can clean up our power plants and still keep the lights on by making better use of existing resources, adding flexibility to our electricity consumption and increasing the efficiency of our homes and businesses.

In July 2010, the EPA proposed the Clean Air Transport Rule (Transport Rule), a Clean Air Act rulemaking to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) from power plants. The proposal targets smog and soot pollution from the fossil energy utility fleet in 31 upwind states and the District of Columbia in order to protect air quality and public health in downwind states. EPA’s analysis shows that the Transport Rule would generate more than $120 billion in annual health benefits (for details, see my colleague John Walke’s detailed post on the proposed transport rule). Next year EPA will propose and finalize critically important Clean Air Act standards to reduce coal- and oil-fired power plant emissions of mercury, arsenic, lead, acid gases and over six dozen other hazardous air pollutants.

The question is, if new clean air regulations lead operators to retire coal-burning power plants rather than comply with the regulations, can we make sure that the lights stay on? The answer is a resounding yes and there are three ways to ensure that’s the case:

1) Using our existing resources. It turns out that the US has a substantial “cushion” of power plants that are underutilized. A recent report from MJ Bradley & Associates and Sue Tierney shows that there are several thousand megawatts of generating capacity beyond what we need to maintain reliability in every part of the country. Also, according to a recent NERC report, even if economic growth picks up quickly, we will still be ahead of their reliability criteria for some time. MIT’s Future of Natural Gas report shows that significant fractions of the natural gas fleet are running at low utilization rates (i.e., operating only 38% of the time on average). Our own preliminary analysis shows even if one were to assume coal retirement rates on the order of 10% of the fleet [1], modest increases in existing natural gas plant utilization could compensate for, and even exceed, lost generation from retiring coal capacity in nearly every region (to decode the region names, click here):

Figure 1. Coal Plant Retirements and Increased Natural Gas Utilization Rates by NERC Region [1]

2) Demand response is a low cost source of flexibility for the grid. A second resource that can help firm up our grid is demand response (DR): allowing factories and businesses to respond to market signals by adjusting their consumption of electricity. This can free up other resources during times of peak demand and contribute to system reliability by adding a source of flexibility to the power mix. FERC’s National Assessment of Demand Response Potential shows that demand response can reduce peak electricity demand by up to 20% compared to only about 5% of total reserves lost through coal plant retirements in even the most dire utility industry predictions. Even in FERC’s moderate DR deployment scenario (their so-called “Enhanced Business as Usual” case), demand response potential exceeds expected retirements in every region save one (with even the difference in that region a mere 2%). And it bears emphasis that we have multiple reliability solutions to draw upon.

Figure 2 Coal Retirements and Demand Response by Census Region [1]

3) Boosting efficiency decreases electricity demand. Energy efficiency can further reduce pollution, ease our dependence on fossil fuels and enable us to power our economy in a smart, clean and reliable way. NRDC’s own preliminary assessment based on data from energy efficiency potential studies from ACEEE and EPRI show that increasing energy efficiency could likely compensate for much or all generation lost through these projected coal retirements.

Figure 3. Coal Retirements and Energy Efficiency by Census Region [1]

So, can we afford to carry out EPA’s upcoming smog, soot and air toxic regulations for power plants? The short answer: We can’t afford not to.

Not only will these rules deliver huge health benefits, but their impact on grid reliability will be minimal. We have three huge resources to address any impacts of coal plant retirements on system reliability and each one is big enough to roughly address this issue on its own: we can better utilize our existing power plants, build more flexibility into our power consumption and run our economy more efficiently. Implementing these solutions together will deliver important benefits on their own (affordable energy, GHG emissions mitigation, renewables integration cost reduction), but as a bonus they help maintain grid reliability and facilitate a much-needed transition away from yesterday’s dirty, polluting energy sources and toward a cleaner energy future.

Many thanks to Starla Yeh and Ted Hesser for their help on the analysis presented here.

[1] Cumulative coal retirement figures (32 GW, nameplate capacity) based on average retirements forecast by Goldman Sachs, Citibank, EEI and Alliance Bernstein with geographic distribution of unit retirements independently derived on the basis of vintage, back end control configuration and capacity factor.

NERC Identifies Solutions to Address the Grid Reliability Challenges of a Transition to Clean Energy

2010-07-29T20:10:01Z

Samir Succar, Staff Scientist, Washington, DC

A recent assessment of the reliability impacts of climate change initiatives paints an encouraging picture of how resources in the pipeline can help enable a major transition to a low carbon economy. The North American Electricity Reliability Corporation (NERC) makes clear that reducing the greenhouse gas emissions of the power sector to meet the carbon mitigation levels consistent with climate science requires a fundamental shift in North America’s resource mix. However, through demand side resources, resource aggregation, energy storage and other strategies we can effectively manage that transition. NERC’s report doesn’t understate the scale of the challenge implied in this huge shift, but it also makes clear we have a broad set of tools at our disposal for getting the job done.

While there are some outstanding issues that need to be addressed, it’s clear that the most pressing reliability challenges will not arise until the 2020-2030+ timeframe. As carbon prices cause increasing numbers of fossil units to retire post-2020, new technologies will be needed to provide low carbon power and manage the variability from renewables:

Large-scale deployment of variable generation will require increased system flexibility to counter its uncertainty and variability. Some potential resources include transmission to support transactions, energy sources from other locations, and technologies that can provide additional system flexibility such as Demand Response, simple-cycle gas turbines, energy storage, transmission, etc.

The good news is that the technologies needed to produce and integrate low carbon power, including compressed air energy storage, dynamic thermal circuit rating, and carbon capture and storage have already overcome significant initial technology risk hurdles through demonstration projects, pilot plants and commercial deployment. Despite uncertainties associated with nascent technologies (e.g. electrochemical storage for transport applications), NERC’s reliability assessment makes it clear that we have a wide variety of technologies to produce low carbon electricity and a broad portfolio of enabling technologies to integrate them into the grid.

The only thing we lack is the political will to get it done.

Meeting the Challenge of 35% Wind and Solar Energy in the West

2010-05-20T20:15:13Z

Samir Succar, Staff Scientist, Washington, DC

A new report shows that the West can get at least 35 percent of its electricity from wind and solar resources by 2017 resulting in reductions in global warming pollution of 25-45 percent. The Western Wind and Solar Integration Report released today by the National Renewable Energy Lab finds that supplying this large fraction of electricity from renewables is “operationally feasible” despite the challenges associated with the variability and uncertainty that wind and solar introduce. This level of renewables deployment also reduces other harmful pollutants (see figure below) and reduces what the West spends on coal and natural gas. The study shows that these reduced fuel and emissions costs result in annual operational savings of up to $20 billion per year.

Emissions impacts of 30% Wind Scenarios vs No Wind Scenarios. "G3.5" scenarios are low natural gas price sensitivity runs.

Increasing the share of non-hydro renewables by a factor of ten will not be easy. The report shows that there are operational challenges to this level of deployment, but it also makes clear that we have the tools we need to integrate renewables at high levels. What is missing is for congress to act quickly on comprehensive climate legislation, a strong renewable energy standard and much needed transmission provisions to provide the long-term certainty needed to drive this level of investment.

What is new here?

WWSIS differentiates itself from prior studies by including solar resources (most large-scale integration studies are limited to wind) and by modeling a relatively high renewables fraction in the generation mix over a short time. This study is a sister study to the EWITS study that I discussed in an earlier post, and like its eastern counterpart this study marks a new geographic scale for this type of analysis, encompassing five major states: NV, AZ, NM, CO and WY.

The footprint of the Western Wind and Solar Integration Study shown in dark blue "WestConnect"

How do we get there?

The critical elements needed to accomplishing this vision are a strong grid and a high degree of operational flexibility. I have mentioned in a prior post how the Danish system relies on a strong transmission network and large-area balancing with its neighbors to get to 20 percent wind and what WWSIS shows is that the same rules apply here in the US.

Getting to 35 percent wind and solar electricity in the West means balancing supply and demand over large areas on the grid so that the system can take advantage of geographic diversity of renewable energy supply (i.e. “the wind is always blowing somewhere”). This requires better coordination on the system and consolidating balancing into fewer, larger areas (WWSIS consolidates 37 existing balancing areas into 5 larger, regional areas).

While the WWSIS is not a detailed transmission planning study, it does show the large amount of power transfer needed to accomplish this level of renewables deployment. This means a significant increase in transmission line development to deliver renewable power to demand centers and to facilitate a large degree of coordinated regional balancing. However, this transmission expansion must be carried out in a way that strikes the appropriate balance between accessing high quality renewable resources and protecting sensitive lands. This also means increasing the utilization of existing transmission lines, maximizing energy efficiency and encouraging the deployment of clean distributed generation.

Successfully implementing a high-renewables scenario like this also means maximizing operation flexibility by scheduling power plants in smaller time increments, using state of the art wind and solar forecasting tools and making the best use of flexible power plants that can change their output quickly to balance the fluctuations from the wind and the sun.

The Time To Act Is Now

WWSIS is an important step forward in our understanding of how we can transform our energy systems to accommodate large quantities of clean, renewable energy. It underscores the point that we have the tools we need on the grid to achieve these ambitious goals. If congress moves quickly to pass a comprehensive energy and climate bill with a strong renewable energy standard and the necessary transmission provisions, we can achieve these goals in a relatively short amount of time. There will be challenges along the way, but the benefits to the environment, our health and our economy demand that we get started now.

Renewables and Energy Storage: A Misunderstood Partnership

2010-03-17T17:50:28Z

Samir Succar, Staff Scientist, Washington, DC

Stimulus funds have provided a big push to the utility scale energy storage sector, but there are still many misconceptions on the role of storage for integrating renewables. Luckily a recent report from NREL provides a great framework for understanding markets for storage, the integration of renewables, and how the two fit together.

Building on the momentum created with stimulus funding announcements a few months ago, we’ve seen a significant number of recent announcements including funding news for General Compression's GCAES concept, progress for PG&E's CAES project, Suniva's Solar/Battery project in Georgia, SCPPA's 53MW Ice Energy thermal storage in southern CA , Iowa’s Municipal Utilities announcement about the beginning of drill tests for their long awaited ISEP CAES project, Xtreme Power's 10 MW dry cell battery plant in Hawaii, Beacon Power's participation in the CEC's wind/flywheel project, Austin Energy's use of Ice Bear for thermal storage, AEP’s Li-ion community energy storage project, funding of 19 energy storage projects by New York State Energy Research and Development Authority (NYSERDA) and Xcel's recent announcement of CAES, NaS Battery and Wind-to-Hydrogen projects.

Also, with storage bills being floated in the house and senate, and a storage portfolio standard being discussed in California, there appears to be growing political support behind the industry as well. All of this activity seems to indicate that utility-scale storage’s “coming out party” is on its way.

But the real question is why do we need all of this storage on the grid? Many assume that the need to balance the variable output from renewables is the principle driving force. This is a topic I’ve covered in previous posts and, as I discussed then, this will certainly be an increasingly critical role for storage. But it’s only the beginning of the story.

Understanding the Role of Storage

When the topic of utility scale storage comes up, the picture that many people have in their head is that of a big battery storing wind energy at night and providing power during midday lulls to make renewables "as constant as coal". Unfortunately, this bears little resemblance to the role that storage will often play on the grid. A recent report by the National Renewable Energy Lab on the role of energy storage with renewables helps to dispel many of the common storage myths and paints a more complete picture of the technologies involved.

I don’t have enough time to cover everything in the report, which includes a comprehensive overview of grid operations, storage participation in restructured markets, storage technology overviews, and renewables integration costs. But I highly recommend reading the full document, available here. In this post I want to highlight two principle points: the multiple markets for storage on the grid and the portfolio of renewables integration strategies (of which storage is a part).

1) The Role of Storage: Beyond Renewables

The first point to understand is that storage has many rolls to play on the grid. A storage plant typically interconnects to the grid as a whole rather than being tied to balancing the output from a specific wind farm or solar plant. This enables storage to effectively participate in multiple markets and generate multiple revenue streams. To understand how those market are subdivided, its important to know that stability of the grid is maintained on several different time scales (see the figure below). These management regimes produce different markets in which storage can participate. An example of this is the California Energy Commission’s wind/storage demonstration project, a flywheel facility providing both balancing support for a local wind farm and frequency regulation services to the grid.

(Denholm et al, 2010)

If you want to delve deeply into this issue, a recent report by Sandia National Labs analyzes seventeen discrete storage applications and their potential. A summary of the results and a good discussion of implications for niche storage markets (as well as a link to the full report) is here.

2) Renewables Integration: The Full Range of Options

To understand the impact of variable generation from wind and solar on the grid reliability, let’s look at two cases. In the first case, the amount of renewables is small enough that the existing amount of flexibility on the system can effectively balance the fluctuations from wind and solar.

(Denholm et al, 2010)

The grid is built to handle a lot of demand volatility and uncertainty (i.e. we don’t know exactly when people will turn on their air conditioners) and therefore small amounts of renewables do not impact system reliability. In the figure above, the net load (total demand for electricity minus the generation from renewables) is within the range where the existing grid flexibility is enough to handle the variability from the renewables on the system.

The more renewables you have, however, the more the net load is reduced. This continues until you reach a point where there are no more flexible power plants that you can back down to accommodate a sudden surge in renewables output. At this point all that’s left are nuclear plants and other "inflexible" facilities that aren’t designed to ramp their output. At that point you need to find something to do with the excess energy.

(Denholm et al, 2010)

Once you hit the point where you have too much output from renewables and nothing left to turn down, it’s time to deploy storage, right? Not necessarily. Storage is certainly one option, but there are several other means of dealing with this kind of issue and some might well be cheaper than storage:

Sharing Resources: Balancing demand and supply over a larger region means that you average out a lot of the peaks and valleys in renewables supply and electricity demand. Supply and demand are typically balanced over an area called a balancing authority. Consolidating these areas or coordinating their operation would allow us to both mitigate the variability of renewables and reduce the demand volatility on the system. This is typically one of the least-cost options available.
Flexible Generation: Natural gas and hydroelectric plants can provide flexible generation. In the figure above, this would increase the height of the dark blue “cushion” and create room for more renewables.
Demand Response: Instead of having flexible supply, you can have flexible demand. This can mean large commercial customers that agree to be shut off, or customers with advanced meters and advanced appliances that shut off when needed.
Curtailment: This means you are discarding some of the energy from the renewables on the system when the net load dips too low. This is not the best case scenario, but the economic hit can be minimal if managed correctly.
New loads: You can absorb some of the excess output from renewables to charge cars, make hydrogen or desalinate water.

(Denholm et al, 2010)

The bottom line is that energy storage and renewables integration certainly intersect, but neither is a subset of the other. We could summarize all of this with a Venn diagram:

What does all of this mean for the storage industry and all of the funds going to support projects in this space? The truth is will need every available option in the red bubble above, and therefore this is the time to invest in proving technologies and buying down the cost of energy storage. The scale of the climate crisis means we need as many options as possible to facilitate the massive task of decarbonizing our power supply. Pilot projects, research programs, demonstrations plants and deployment incentives today will make sure we have the tools we need to meet the daunting challenges that we face. Ideally incentives will be structured in a way that directs those investments effectively to produce the best outcomes at the lowest cost, but thats a topic for another post.

All images are shown courtesy of NREL and reproduced from the report reviewed in this post:

Denholm, P; Ela, E.; Kirby, B.; Milligan, M. (2010) “The Role of Energy Storage with Renewable Electricity Generation” NREL/TP-6A2-47187

http://www.nrel.gov/docs/fy10osti/47187.pdf

Many thanks to Carlin Rosengarten and Cai Steger for their help putting together this post

(bonus for reading this far: more Venn diagram fun)

China pulls ahead of US in Wind (Or Maybe Not?)

2010-02-03T17:01:53Z

Samir Succar, Staff Scientist, Washington, DC

Despite earlier claims that the near-10 GW of US wind installed in 2009 might edge out China in wind capacity additions:

The wind industry installed more than 9,900 megawatts of generating capacity, AWEA said. The association says that is enough to serve more than 2.4 million homes, about as many as there are in Washington state. Bode said that meant the United States should edge China for the lead in wind power installation for 2009. (from E&E news, subscription req'd)

It looks like China has taken the lead in wind with 12+ GW installed last year

China became the biggest market for new wind turbines last year, as it doubled power capacity from 12 gigawatts to 25 gigawatts. (from Business Week)

Although, if ~30% of those new turbines sit idle, the US might still be on top in terms of new wind energy delivered (the issues around wind interconnection in China are covered in detail in this excellent post). Of course regardless how you view the 2009 numbers, the phenomenal growth of renewables in China points to a larger trend and its pretty clear where we are headed. However, putting the question of US/China wind growth aside, there's a more fundamental point here.

Despite who is "ahead", the issue is not how many wind turbines or gigawatts a country can install, but how much renewable energy those projects provide to that nation's homes and businesses. Installed capacity is fundamentally the wrong measure for determining the success of a renewables deployment program. Furthermore, by focusing on energy delivered rather than turbines installed, we get at some of the infrastructure and integration challenges of this large scale shift to clean energy which are becoming increasingly urgent. The US must address these bottlenecks in order to realize the promise of a clean energy economy and remain global leaders in emerging energy technology development and manufacturing.

Also, as I've suggested before, the US may soon face its own deterioration of wind project capacity factors if we don't quickly move away from the current investment-based incentives made available in the stimulus, and return a performance-based vehicle like the production tax credit. Time will tell...

Eastern Wind Study from NREL Provides An Important Step Forward

2010-01-20T15:38:06Z

Samir Succar, Staff Scientist, Washington, DC

Today the National Renewable Energy Laboratory released a new wind integration study titled the Eastern Wind Integration and Transmission Study (EWITS). The study examines the infrastructure needed to increase the share of wind energy to 20-30% (today wind is about two percent of US electricity). The report is significant in that it shows the importance of including offshore wind in a large scale integration study. EWITS also makes clear that a large amount of transmission will be needed to deliver enough wind to meet a 20-30% goal (especially from southwest portion of the eastern grid). It is an important step forward, but only one of many as much still remains to be done in this area.

The "Eastern Interconnect" is the biggest of the three independent US grids (the eastern grid accounts for over 70% of the electricity consumed in the US), which means that reaching high wind penetrations in East requires a lot of turbines. EWITS projects that about 340,000 MW of wind power will be needed to reach wind penetrations of 30%. In terms of maximum output power (i.e. installed capacity) that's equivalent to more than 400 large conventional power plants.

EWITS shows that this level of wind deployment is a major challenge, not only due to the number of wind turbines, but also because of the thousands of miles of new power lines needed to get that electricity to market. Installing a large amount of wind requires substantial investments in new transmission lines because the best resources aren't in areas of high population density. We can look at the EWITS wind projections per region as a fraction of total demand for electricity to get a sense of how much this level of wind development would overwhelm existing power infrastructure:

Regional wind capacities in EWITS scenarios divided by 2006 peak load by region

This figure shows that in the Southwest Power Pool (SPP), the amount of wind in EWITS Scenarios 1, 2 and 4 is equivalent to more than 2 times the total peak power needs in the region. The amount of wind projected in SPP far outstrips all previous wind integration scenarios. In fact, a wind integration report for SPP released yesterday looks at wind deployment scenarios up to 25 GW (40% wind in SPP), which is only half of what EWITS projects, even in their least onshore-intensive scenario (Scenario 3), and less than 30% of the wind deployment projected in the other scenarios. The level of grid infrastructure development needed to maintain system reliability with such a high amount of wind clearly represents a major challenge.

What's new here?

There have been a large number of wind integration studies done in the past (a good review is here), but most of them have had limited geographic scope and resource base. Last year the Joint Coordinated System Plan (JCSP) took an important step forward by providing a model of the entire eastern interconnection in their high penetration wind scenario modeling. EWITS builds on this earlier work but takes another important step forward, looking not just at onshore wind resources, as the JCSP had done, but also integrating offshore wind resources.

Wind Resources in EWITS Scenario 3

Offshore wind is, potentially, an enormous source of power that is often relatively close to population centers, thereby reducing the amount of transmission needed to integrate large amounts of wind into the grid. Scenario 3 in EWITS is an aggressive local/offshore case with over 64 GW of offshore development. Its results project that a 20% wind penetration can be reached with 25% fewer miles of new transmission relative to the all-onshore wind case (Scenario 1).

The conclusion one can draw from the EWITS study is that offshore is a potentially critical resource that can have significant impacts on how we decarbonize the electric power sector and reduce the scope of infrastructure development that will be required to support a large deployment of renewables on the system.

The study also makes clear, however, that this does not eliminate the need for transmission to bring wind power from the Midwest. Even in the aggressive offshore case, over 17,000 miles of new transmission are needed including over 12,000 miles of the highest voltage AC (765kV) and DC (800kV) lines. Midwest onshore wind is the cheapest source of utility-scale renewable energy available in the East; offshore wind doesn't obviate the need to exploit onshore resources and it certainly doesn't eliminate the need for transmission.

What's Next?

EWITS, like the JCSP before it, signifies an important step forward in our understanding of how variable generation can be integrated to the grid in large quantities. But there is still much that remains to be done. The addition of offshore wind resources is only the first step in understanding the full range of options available to facilitate the integration of renewables.

An aggressive deployment of energy efficiency, demand response, energy storage, distributed generation, and improved systems operations (e.g. dynamic thermal rating, increased system scheduling frequency, conditional firm services) can go a long way toward integrating variable generation into the system. EWITS takes one step in this direction by looking at the impact of consolidated balancing authorities (control areas) on wind balancing, but there is certainly more study needed to identify the full portfolio of options available to integrate wind.

As system planners start to undertake the interconnection-wide planning funded by the stimulus, these kinds of modeling exercises will form an important foundation for the analysis needed to extend wind integration studies into system planning and, eventually, implementation. Newer efforts, such as NREL's SolarDS model development, will help to better integrate rooftop and wholesale distributed solar into these kinds of modeling efforts. Also, the EWITS sister study in the west has begun to look at how utility scale solar and wind can both be deployed in large quantities.

The challenges we face are enormous. Planning tools have been extended to unprecedented geographic scope and have begun to integrate a wide range of new resources into the generation mix. But we must still push to look at all supply *and* demand side resources at our disposal and simultaneously plan for ever-broader time horizons to meet the challenges of addressing climate change and transitioning to a clean energy economy.

The Danish Wind Experience: Truth and Fiction

2009-09-14T23:44:42Z

Samir Succar, Staff Scientist, Washington, DC

This CEPOS study by Hugh Sharman about the Danish wind experience has begun to receive a great deal of attention. The study provides a great account of how the Nordic grid has been effectively used to manage the fluctuations from wind power on the system and points to the crucial role of grid infrastructure for integrating wind. Unfortunately the central message of the study has been hijacked, and its central points heavily distorted. Instead of dwelling on IER's misrepresentations, let me elaborate on what the study does say:

On the emissions benefits of wind

The author points out that because of the cost dynamics on the Danish grid and the way coal power is used, wind doesn’t reduce the emissions on that system. However this is simply an artifact of the how the Danish market is structured and how their power system is managed. It bears no relationship with how the US grid is governed or operated. In fact, given the heavy use of coal and natural gas in the US grid, the addition of wind to the US grid to displace conventional generation has the potential to greatly reduce greenhouse gas emissions.

On the Cost of Danish Power

The cost of electricity in Denmark is high, but this is a result of tax policy, not wind. According to Eurostat, the European Union’s official statistics agency, the pre-tax price of electricity for an average medium household in Denmark is 120€ per MWh, which is virtually equivalent to the European average of 119€ per MWh. The pre-tax price of electricity in Denmark is actually 23 percent lower than Ireland as well as significantly lower than the United Kingdom (by 14 percent) and Germany (by 7 percent). After taxes are taken into account, the price comparison is slightly different: the electricity tax in Denmark means the net price of electricity is higher than the European average. But as the CEPOS study points out, this is a function of Danish policies, not a result of wind deployment.

On 20% Wind and the Implications for the US

Denmark is a small country with a population is less than that of Maryland but yet it has been able to develop a great deal of wind power. The reason is that Denmark has a very strong connection with neighboring grids and can use Norway and Sweden’s hydropower to balance the fluctuations that wind imposes on the system. In the words of the study's author:

It was a lucky coincidence that although Denmark has no electricity storage within its electricity system, it has, for many years and for reasons having nothing to do with balancing wind power, been strongly inter-connected with its neighbours, Germany, Norway and Sweden. These have much larger power systems. To the north, the largely hydroelectric systems of Norway (99% hydro) and Sweden (40% hydro) are able to balance the stochastic variations in Denmark’s wind power by continuously turning their hydropower systems up and down. When “excess” windpower electricity flows along the inter-connector into Norway (for example), hydropower can be rapidly turned down to match, effectively “storing” Danish wind power in Norway. As the wind energy falls or ceases, the “stored” electricity can be released very efficiently to make up any shortfall in West Denmark. The electricity trading market responds to fluctuations in the spot price (i.e. instantaneous commercial value) of power. In this way, Denmark’s two closest two Nordic neighbours effectively act as Denmark’s “electricity storage batteries”.

The message is abundantly clear: a strong grid and responsive power plants (such as Norway and Sweden’s hydroelectric fleet) make integrating wind much easier. In fact Denmark's total wind generation is almost 20% of the nation's total elecricity consumption. It is true that not all of Denmark's of windpower is used inside its borders, but that only speaks to the importance of integrating wind over a large area and the use of a strong grid to balance out fluctuations from variable renewables. While individual US states may get an a large fraction of their power from wind and solar, it certainly doesn't make sense to force all of that power to stay inside their borders. The use of robust connections with neighboring regions allow excess wind to be transported outside the wind producing region during times of high wind output and likewise wind lulls can be compensated with increased output from dispatchable renewables (in this case hydro):

H. Sharman “Wind Energy: The Case o Denmark” CEPOS 2009

As the author seems to imply above (and as I recently mentioned on this blog) another strategy for integrating wind is to use energy storage. However these are only a few of the many tools available for integrating wind on the system. Two other critical tool include demand side management enabled through grid communication infrastructure (i.e. the “Smart Grid”) and use of advanced wind forecasting tools.

Regardless of what means are used to integrate wind, it is important to keep in mind that the cost of inegrating wind is only about 10% of the whoesale cost of wind energy (see balancing costs below) and places that have very little wind power (like most of the US) can integrate wind at even lower cost. In fact, where there is spare natural gas capacity on the system, that cost can be minimal.

H. Holttinen, et al, "Design and operation of power systems with large amounts of wind power: State-of-the-art report " VTT Technical Research Centre of Finland, Vuorimiehentie, Finland VTT–WORK–82, October 2007.

The US gets about 2% of electricity from wind which means variability is not a fundamental barrier in the near term. However, grid access (or lack thereof) is quickly becoming a barrier to wind development in the US and it is clear that we will needs to move forward on well-sited transmission lines that will help facilitate the continued growth of wind.

This recent Danish study provides a valuable data point on how grids can be managed to accommodate high penetrations of renewables. The lessons learned are not directly transferrable and integration solutions will vary by region, but is clear that a strong grid will play an important role in the large scale deployment of variable renewables. Regardless of how we get there, wind is a critical large-scale, low-carbon energy resource and an important means toward achieving a clean energy future.

Thanks to David Cohen-Tanugi for help in preparing this post

Does Wind Need Energy Storage?

2009-08-27T15:30:06Z

Samir Succar, Staff Scientist, Washington, DC

With the recent news of PG&E's bid for stimulus funds for compressed air energy storage (CAES) to balance wind, the question again arises whether energy storage is really necessary to put wind and other variable renewables on the grid. I believe the answer is a qualified yes.

On the one hand, it has become almost cliché to call energy storage the holy grail of renewable energy and recently it seems the space is getting increasing levels of interest from investors, lawmakers, and venture funds alike. However the wind industry itself has been quick to downplay the importance of storage. In response to another recent piece on CAES Michael Goggin of the American Wind Energy Association suggested that "it's important to temper enthusiasm about storage with the recognition that wind power can be integrated onto the electric grid without energy storage."

The truth is that today wind is only about 2% of the US electricity supply, and at current levels of penetration wind can often be readily integrated without impacting system reliability. But wind power is growing quickly, and if it is to be a part of our nation's solution to global warming, it must continue to do so on a big scale. This means in the long term we will need every cost-effective means at our disposal to integrate renewables. This includes aggregating diverse resources (geographically distributed wind, wind and solar, etc), demand response, careful use of hydroelectric and natural gas plants that ramp quickly to balance wind's fluctuations, and yes, energy storage.

Technologies like CAES have important, unique advantages. For example, storage can be used to provide more constant power output to fill power lines. Ultimately, that means that for each unit of wind power, we need less high voltage transmission capacity, and ultimately that means less "energy sprawl". Furthermore, if wind and storage can displace coal directly by producing baseload power, that increases the greenhouse gas abatement value of wind substantially.

While there is some degree of hype in the recent buzz around these technologies, its clear storage will provide real benefits to the system as the contribution from variable renewables continues to grow. And although the variability of wind is not a barrier to its growth today, energy storage could nevertheless play a critical role in paving the way toward a clean energy future.

Wind Report Shows Costs Leveling Off

2009-07-22T21:05:31Z

Samir Succar, Staff Scientist, Washington, DC

LBNL/EERE released another annual report on wind market trends. It covers the usual collection of market data points, capacity additions, etc.

PDF: http://eetd.lbl.gov/ea/ems/reports/2008-wind-technologies.pdf

LBNL Publications: http://eetd.lbl.gov/ea/ems/re-pubs.html

Notable among the findings is that US now tops international wind capacity rankings (that is, until China catches up ).

Also worth noting is that wind represents the largest fraction of capacity additions of any class of generation. Wind has clearly now moved into the mainstream of the US power market and although the industry is growing from a small base, there is no doubt it has the scale to quickly become a significant part of our generation mix

However the part that really caught my eye this year were the cost trends. While the capital cost of wind power declined substantially through 2000, the recent trend has been cost escalation. Although we continue to see that trend in project costs,

Wind turbine cost (which drive future project costs) have for the first time started to show some levelling off:

As these costs enter the project pipeline we might hopefully see this trend carry through to declining wind project costs as well

Energy and commodity prices have dropped substantially since mid-2008, however, and the supply-demand balance for turbines has resulted in a turn towards a buyer’s market. As a result, rumors abound of price reductions in the 5-20% range (NEF 2009), or even as high as 25% (Hays 2009), of increased availability of turbines in the “gray” (i.e., secondary) market (Goodwin 2009), and of more favorable terms for turbine purchasers. These price reductions and improved terms can be expected, over time, to put downward pressure on total project costs. (p. 36)

This trend toward lower costs, driven by lower prices for steel and other raw materials, has begun to propogate throughout the power sector.

(from M Al-Juaied, A Whitmore, "Realistic Costs of Carbon Capture" Discussion Paper July 2009 )

Therefore its possible that with similar cost declines throughout the sector, the relative economics of wind will not change appreciably, but these are neverheless positive signs.

Its also worth noting that the cost of O&M (operations and maintenance) has declined somewhat. Although the trend is not clear cut, hopefully this points to new new designs with improved reliability, reduced levelized replacement cost and enhanced lifetimes.

The capacity factors of wind have seemed to level off, although at a fairly high level.

This is not surprising, but my fear is that as the industry transitions from the production tax credit (PTC) to stimulus grants, we may see this trend turn over. The PTC offers tax credits on the basis of a wind farm's output giving the industry a strong performance incentive, but the grants made available through the ARRA are invstment-based and lack the incentive to maximize energy production. This kind of policy support has been problematic in Germany and China, and we may well see much lower capcity factors over the near term if the industry makes a significant transition to these stimulus grants.

Stimulus Funds Continue To Push Clean Energy Forward

2009-05-04T19:04:53Z

Samir Succar, Staff Scientist, Washington, DC

Over the weekend, the Department of Interior announced a new initiative funded through the stimulus that includes $41 million to "advance the nation's development and transmission of renewable energy on public lands." Other portions of the $300 million will be dedicated to regional renewables projects, energy efficiency investments as well as a host of regional initiatives and various land restoration projects. However, as transmission development for renewables expands, lets hope that we can continue to find better ways to plan the lines by informing the process and ensuring its done right. (btw, meetings on transmission continue in the senate this week)

Other announcements include the President Obama's April 27th speech announcing of a $400 million kick-start from stimulus funds for the creation of Advanced Research Projects Agency-Energy (ARPA-E) that provides funding for basic research on energy technologies, a $300 million department of energy funding announcement for the Clean Cities Program and the announcement of 46 new Energy Frontier Research Centers partially funded through the stimulus.

And of course all of this is in addition to renewable energy provisions launched in February as part of the stimulus bill.

Where does this leave the prospects for clean energy? Can we expect a bright future for renewables despite our economy's current woes? Its clear that some are feeling bullish; lets just hope that optimism is contagious.

A Fresh Look at the Grid – Connecting the Dots with New Interactive Tools

2009-04-30T20:22:48Z

Samir Succar, Staff Scientist, Washington, DC

All of a sudden, congress isn't the only place where the electric grid is getting attention. In addition to transmission legislation recently introduced in the senate and the house there seems to be a flurry of reporting on grid issues lately. Some notable examples include Renewable Energy World, which is taking a month to look at issues around the smart grid on its podcast and NPR, which is devoting 10 episodes to grid issues through May 1st in a series they call "Power Hungry."

The NPR stories cover a broad range of issues from an examination of the true environmental benefits of the smart grid to land conservation issues associated with new power lines. It's a good overview of the subject with some nice interviews including a conversation with Jon Wellinghoff, the new progressive chair of the Federal Energy Regulatory Commission (FERC). The accuracy is fairly good, but I did notice one discrepancy. In one piece they claim that wind power can't be stored, but in another they devote considerable attention to storage technologies and the various ways to store renewables. Unfortunately this kind of inconsistent reporting on energy storage is fairly common, but I'll leave that topic for future posts.

The best part of the NPR coverage however is their interactive map that lets you explore transmission lines, power plants, state generation mixes, renewable energy resources. This is a very bookmark-worthy resource and I would definitely recommend taking some time to explore all the layers of information that it offers.

As mentioned earlier here on Switchboard, NRDC recently launched a new renewables website with our own mapping tool showing the location of several classes of renewable power generating facilities (both planned and existing) and indications of resources strength.

In addition, NRDC recently launched another great mapping effort with Google.org and the National Audubon Society aimed at identifying areas of greatest renewable energy potential and where development would have the least harmful impact on valuable natural resources.

This is an ongoing collaborative effort aimed finding ways to accelerate renewable energy deployment while not compromising critical land conservation goals.

That should be enough to satiate you inner cartographer for one day!

http://npr.org/grid

http://www.nrdc.org/renewables

http://www.nrdc.org/PathtoGreenEnergy