California has too much solar power. It needs another grid to share with.

This article was originally published on VOX.com on April 8, 2016 and was written by David Roberts

The US has no national electricity grid. Instead, it has a patchwork of grids, operated as closed-off regional and local fiefdoms with little trade among them.

One of the most important steps America can take to integrate more wind and solar power is to connect and expand those grids.

California is trying to take a small step in that direction. In the process, it is revealing the kinds of political tensions that stand in the way of grid integration.

California needs somewhere to put all its solar energy

The story comes to us via an excellent report by Lauren Sommer at KQED Science. It’s about a problem that’s beginning to hit in California — and will hit in other places in years to come, as renewable energy spreads.

Every so often, solar panels in California produce more solar energy than the grid needs. When these oversupply events occur, grid operators manually “curtail” solar production, cutting some panels off from the grid, effectively letting clean, zero-carbon energy go to waste.

solar curtailment
The dreaded curtailment in California on March 27, 2016.

This doesn’t happen all that often yet — roughly 2.2 GWh of renewable energy were curtailed due to oversupply in 2014, relative to the 44,000 GWh of renewable energy the grid used — but the problem is expected to get worse as wind and solar expand in the state.

This illustrates the key challenge that wind and solar (together known as variable renewable energy, or VRE) pose to self-contained grids: their intermittency. A lot of solar comes flooding in at midday, and then it all goes away at night. Sometimes it can go away all at once and come back a few minutes later (a phenomenon known as “clouds”). Wind can come all at once and then die down all at once.

It’s a challenge for today’s grids to handle both the quantities involved at peak VRE production times and the steep “ramps” up or down in supply and demand that come with VRE.

california's duck curve.
Fear the duck.

There are many ways to tackle the challenges of integrating VRE. I’ve written about the big picture here and more fine-grained, near-term solutions here.

But perhaps the easiest way to solve the problem, or at least postpone it, is to make the grid bigger. The larger the geographical area the grid covers, the more variations in supply and demand can be smoothed out. When one area is at peak VRE production, it can ship power to other areas rather than curtail it.

That’s just what the California Independent System Operator (CAISO) wants to do: link up California’s grid with those around it. “You’re operating your little piece of the system,” CAISO VP Keith Casey told Sommer of KQED, “but if you can operate it as an integrated whole, you can just operate the system more efficiently.”

Conceptually, this makes all the sense in the world. When it comes to the details, though, the politics can get sticky.

California’s clean grid meets PacifiCorp’s dirty one

There are a number of grid “balancing authorities” (grids run by particular utilities) near California, to which it could theoretically connect:

western interconnection balancing authorities

(Follow the link to see what all those acronyms stand for.)

CAISO’s first partnership is with PacifiCorp, a utility that runs a grid in Wyoming, Idaho, Utah, and Oregon.

CAISO and PacifiCorp.
CAISO and PacifiCorp.

(Earlier this year I wrote about Oregon’s pledge to go coalfree and how it would affect PacifiCorp.)

There are already some (currently little-used) power lines strung between the two regions, which could be used for greater coordination between CAISO and PacifiCorp. So they are planning an integration of their operations, scheduled to be in effect by 2019:

CAISO integration plan

A PacifiCorp-funded study found that the integration would benefit ratepayers across both regions. And it would certainly help CAISO find a way to export (rather than curtail) its excess solar energy.

But there’s a wrinkle.

If CAISO and PacifiCorp become one big grid, it opens up all sorts of regulatory and legal questions. Who manages an interstate grid? Who regulates it? Do California’s laws apply to it? Can they, legally speaking?

PacifiCorp is a big owner of coal plants — 60 percent of its energy comes from coal. All that coal will now effectively be on California’s grid. California has worked hard, economically and politically, to clean up its grid. What will happen to that progress?

These concerns led several state lawmakers to write the governor laying out a list of “significant unanswered questions” and requirements related to the integration.

California lawmakers' signatures. "Don't forget geothermal!"
California lawmakers' signatures. "Don't forget geothermal!"(CAISO)
California lawmakers’ signatures. “Don’t forget geothermal!”

They want to ensure that California’s pollution and greenhouse gases continue to be reduced, that California’s renewable energy mandates continue to be met, that California ratepayers benefit, and that investment not be shifted into PacifiCorp’s territory at California’s expense.

And because CAISO and its board were created by the legislature, presumably a new act of the legislature would be required to expand them, so these legislators will have to be heard and satisfied. (I asked a top staffer if their questions had been answered to their satisfaction; they have not.)

These parochial concerns make complete sense. These politicians are, after all, representing Californians.

But the bigger picture remains: Grid expansion has to happen eventually. The climate certainly doesn’t care about California’s emissions; it only cares about total emissions. If sharing VRE with PacifiCorp lowers overall emissions, it is to the good, even if Californians consume less VRE than they might otherwise have. Somehow, the economics and politics of grid expansion have to be worked out.

The perils of state-based climate and energy policy

California’s experience reveals some of the dysfunctions that come with the US lacking a coherent national climate policy. When each state with green ambitions has its own regulations, its own targets, its own mandates, even its own grid, it can feel protective of its own progress and loath to dilute it by hooking up with more laggardly states.

California has installed a lot of distributed solar PV.
California has installed a lot of distributed solar PV. (EIA)
California has installed a lot of distributed solar PV.

And California legislators are not crazy to feel that way. Wyoming and Utah are fighting tooth and nail against Obama’s Clean Power Plan. Wyoming is deeply invested in coal production. Oregon-based PacifiCorp is heavily invested in coal plants (though it ismoving away from them). Opening CAISO’s grid to possible federal oversight also opens it to various federal lawsuits, many launched by laggardly states, meant to stop clean energy regulations.

Then again, it’s the laggardly states that need the renewable energy, and the clean states that have got it — in California’s case, at least temporarily, too much of it.

Hooking up into larger and larger grids is part of the logic of transitioning to clean energy. It is necessary in order for California to hit its ambitious 50 percent renewables target. And it’s probably necessary in order for the US to hit the targets it promised in Paris.

On some time scale, a national grid is both necessary and inevitable.

In addition to their utility, power lines make for very dramatic photographs.
In addition to their utility, power lines make for very dramatic photographs. (Shutterstock)
More of these.

Transmission is a one-time fix

Variable renewable energy poses what you might call “whole system” challenges to energy grids. Once VRE rises to a certain level of penetration, it begins to swing between producing more energy than the system needs to and producing, in periods of extended calm or clouds, almost none.

Unless you can do something about those huge peaks and valleys, you need almost 100 percent redundancy — enough backup power plants to supply 100 percent of demand in the event that VRE is providing none.

But big coal and nuclear plants can’t just turn off in the morning and turn on in the evening. Even where they are physically capable, it’s too expensive. So you end up needing lots and lots of natural gas plants. Not ideal.

The way states and countries have achieved high VRE penetration to date is by cheating these whole-system problems. They cheat it by making the system bigger, hooking up transmission to surrounding grids so that they can offload the their occasional VRE surplus and import power to back up their VRE.

That’s what Denmark did, linking its grid to Sweden, Norway, and Germany so that it can export wind power when it has more than it needs and import power when the wind is idle.

denmark interconnections
Denmark, connected.

That’s what CAISO is trying to do, linking to surrounding Western states.

But note that this is a one-time-only way to postpone the problem. Eventually states or regions are going to reach a point where there are no more bigger grids to hook up. And then the whole-system problems return. At that point, the system can’t be made any bigger, so the problems have to be solved some other way.

We still have to sort out storage and shift demand

One way to tackle the problems is cheap and effective energy storage, to absorb the midday VRE surplus and return power at night or when it’s cloudy.

the garage of the future

The other big one is figuring out ways to shift demand so that it coincides better with periods of peak VRE production. There are lots of ways to do that, from incentives that change human behavior to automated networks of electric vehicle batteries to … water heaters.

California is smart to set its sights on a bigger grid. It will ease the immediate problem. But the state should also be pushing as hard as possible toward better storage and better demand shifting (and all the other strategies I covered here), because sooner or later the whole-system problems have to be solved, and the sooner they are, the greater the long-term payoff.

The Polar Vortex and the Power Grid: What really happened and why the grid will remain reliable without soon-to-retire coal plants

This piece is cross-posted from The Sustainable FERC Project’s blog.

Apr 29, 2014

by John Moore and Allison Clements

In the grip of the “Polar Vortex,” much of the nation experienced an extremely cold winter. The good news is that despite record electricity demand and some of the coldest weather in 20 years, power companies and grid operators kept the lights and heat on. Yet some observers are now claiming that this past winter’s experience casts doubt on whether the power system can cope without the aging coal-fired power plants that are slated to retire over the next couple of years in the face of competitive pressures.

Fortunately, the nation’s major grid operators – the entities charged with maintaining the power grid’s reliability and keeping the lights on – disagree. This fact sheet explains what happened on the grid during the Polar Vortex and clears up misconceptions about what the experience means for both future extreme weather conditions and implementation of the US EPA’s carbon pollution standards.

Q: It’s been reported that many old coal plants that are slated to retire next year were needed during this winter’s extreme cold snaps. For example, American Electric Power (AEP), one of the country’s largest power companies, reported that 89% of its coal plants scheduled for retirement ran during the Polar Vortex. Why did so many old coal plants run this winter?

Old coal plants ran so heavily because an unusual number of other plants were out of service during the Polar Vortex for a variety of exceptional weather-related reasons that are being fixed going forward. Coal plants slated for retirement won’t be needed when these exceptional outage problems are fixed.

Most of the plants that were out of service were unavailable because of operational and mechanical problems like frozen coal stockpiles, boiler tube failures, and faulty ignition. Some plants, for example, failed to start up in the extreme cold after being off line for months. (By the end of January, when we experienced another extreme cold spell, more plants had recovered and were running normally.) Grid operators are now working on corrective measures to avoid these surprises, including requiring plants to test and verify their operational capability during the cold winter months. These tests include a “weekend check” requirement to assure that plants won’t have trouble starting up again after a prolonged break. Grid operators are also evaluating additional financial incentives to reward plant operators that deliver higher performance levels.

Cold weather conditions also revealed problems with natural gas procurement practices, even though sufficient gas supply was available throughout the period. In addition, a glitch in the power and gas markets kept some gas-fired generators from obtaining sufficient fuel on high-demand days – power markets in some regions declare their next-day needs too late in the day for gas markets to respond. The Federal Energy Regulatory Commission (FERC) and the grid operators responsible for maintaining a reliable electric grid are working to fix this problem before next winter.

RTOs, ISOsQ: So, in light of the stresses during this winter’s Polar Vortex, aren’t these retiring coal plants really needed next year?

Not according to PJM, the nation’s largest grid operator with more than 180,000 megawatts (MW) of power plant capacity throughout the Mid-Atlantic and Midwest. Like other regional grid operators, one of PJM’s core responsibilities is to ensure through future planning that sufficient power generation, transmission lines, and other grid resources will be available to maintain reliability and keep the lights on. After a thorough assessment of reliability concerns, PJM has determined that all nine of the soon-to-retire AEP plants in its region (accounting for about 5,400 MW of capacity), plus thousands of megawatts’ worth of other power plants can cease operations without causing any grid reliability problems. Reflecting on the Polar Vortex in April, PJM informed FERC that it will have more than enough power to meet reliability needs after accounting for all planned retirements from companies across the region.

PJM secures necessary power supplies through an annual auction that runs three years into the future. As a result, PJM has determined that its needs through 2017 will be met by existing coal, gas, and nuclear power plants supplemented by nearly 19,000 MW of new power generation, energy efficiency resources, and power imports from neighboring regions of the country, plus over 12,000 MW of “demand response.”[1] The combination of resources will more than offset the approximately 15,000 MW in expected regional coal plant retirements, leaving PJM with about 20 percent more capacity available than needed to meet projected demand.

Q: What about other regions? For example, I’ve heard that the grid operator Midcontinent Independent System Operator (MISO) is worried about insufficient power capacity in the future – is that true?

MISO operates the grid in all or part of 15 states in the Midwest and South. On April 15, MISO reported to FERC that it has more than enough power capacity and demand response resources to meet this summer’s and next winter’s projected demand. Similar to PJM, new plants, energy efficiency investments, and other measures are replacing plants slated for retirement. Looking ahead to winter 2015/2016 and through the end of 2016, MISO and its participating states believe that the region is very close to meeting its power supply requirements. MISO’s analysis is ongoing, and more power may be available from the southern part of MISO (Arkansas, Mississippi, Texas, and Louisiana), which has extra capacity, and from imports from the neighboring RTO, the Southwest Power Pool.

Q: How can we be sure the grid will stay reliable in cold weather conditions after upcoming compliance deadlines arrive for new environmental protection standards?

Grid operators are planning to meet their capacity needs (including during hot and cold snaps) taking new environmental rules into account, including for example US EPA’s Mercury and Air Toxics Standards (MATS). Acknowledging that a variety of factors – not the least of which is low-cost natural gas – create the potential for additional coal plant retirements and that work needs to be done to address fuel supply issues, none of the grid operators has told FERC or Congress it supports a delay of the MATS standard or of the forthcoming carbon pollution standards. In fact, some of the operators have commented that it does not make economic sense to pour money into retrofitting and retaining older, less reliable plants, because that diverts investments away from newer and more reliable plants.

Q: Can we be sure the coordination issues between natural gas markets and power markets will be fixed?

FERC and the grid operators started addressing these issues before the Polar Vortex began, and they have opened related rulemaking procedures in all relevant regions. Planned changes include better coordination of the daily natural gas and electricity markets to make sure that gas can be delivered when needed, and changes to make it easier for gas-fired plants to run on oil during any gas supply shortages that do occur. This dual-fuel capability helped many plants in New England to operate successfully in January and February (although burning oil instead of gas increases pollution and should be viewed only as a remedy of last resort).

Q: Did wind power help or hurt during the Polar Vortex?

Wind power contributed to the grid’s reliability during this winter’s cold weather. In Texas and the Mid-Atlantic/Midwest, wind energy supplied thousands of megawatts of power during critical times, helping to temper some price spikes and avoid blackouts. The California Independent System Operator, which operates most of California’s grid, told FERC at an early-April meeting on cold weather operations that “renewables helped to get us through the winter.” Likewise, the New England ISO recently told the House Energy & Commerce Committee that renewable energy resources “were an important part of the energy mix” during the past winter. As wind power continues to expand throughout the country, it is becoming more valuable to grid operators during periods of winter peak demand. Throughout the various cold snaps in New York, the nearly 1,400 MW of wind in the NYISO market performed very well, contributing low cost emissions free power during high demand.

Q: How did energy conservation help during the cold weather? Did utilities force people to cut back on home heating during the Polar Vortex?

Energy efficiency and demand response programs[2] helped the grid get through this winter, but no customers were ordered to cut back. Manufacturers, businesses, and other large customers in the Mid-Atlantic and Northeast regions responded to demand response financial incentives by voluntarily reducing peak electricity use to the tune of 3,000 MW during the Polar Vortex. As the New England ISO recently reported, demand response resources “performed well and were a valuable part of maintaining reliability during the winter season.” All regions are now evaluating ways to expand the amount of demand response available to meet winter peak demand needs.

Q: Are all these retirements going to cause sticker shock in coming electric bills?

There’s no getting around the fact that we use more power when it’s extra cold. So it’s no surprise that power bills went up during this extreme winter. It is also true that high gas demand led to temporary regional gas price spikes, which translated to higher energy prices for short periods during the extreme cold. Though the peak prices paid by utilities were high, the final cost felt by consumers was tempered by the fact that these high prices were temporary and some retail rate structures shield residential consumers from these costs.  Going forward, FERC and grid operators are now working to reduce gas price spikes through better market rules and other solutions. Also, gas prices are lower overall on an annual basis than in the past.

Q: How can energy efficiency and renewable power help meet peak power needs and keep bills down?

The cold weather events highlight the important role that energy efficiency can play in meeting peak power needs and holding down bills. Grid operators in the Mid-Atlantic (PJM) and Northeast (ISO-NE) have used efficiency in their electricity markets to reduce electricity needs by several thousand megawatts. Unlike coal and natural gas plants, energy efficiency performs well in all weather conditions while costing less than half as much as building new generation. Renewable energy offers zero-cost fuel no matter the weather – and some renewable resources perform at very high levels during the winter months when gas supply is under the most pressure. Expanding these resources is the best way to meet our energy needs – both on an every-day basis and in winter and summer extremes.

You can find more information on how grid operators plan for higher-than-expected electricity demand here.

[1] See PJM, 2016/2017 RPM Base Residual Auction Results, at 1. Demand response programs allow industrial, commercial, and even residential customers to enter contracts to cut their electricity use for short periods in exchange for a bonus payment, if the grid operator determines there is too much demand at a particular time. Demand response programs contributed to grid stability during the Polar Vortex.

[2] See note 1, above.

Letter to WSJ: We Need a Modern Electrical Grid and Must Pay for It

The following is a letter written by former Chairman of FERC and member of Americans for a Clean Energy Grid Jim Hoecker to the Wall Street Journal in response to an article called “The Wind Power Tax.” The letter was published in the WSJ and is cross-posted here.

February 21st, 2013

Your editorial “The Wind Power Tax” (Feb. 11) registers your opposition to modernity and clean-energy development by attacking investment in electric transmission, which is essential to connecting renewables to customers.

You ignore basic facts. Transmission, which is less than 10% of electric bills, is an integrated network that serves multiple societal needs. Major transmission additions are needed to ensure our nation’s electric reliability, replace aging and outdated facilities and reduce the extraordinary costs of congestion on the grid. Only about one-third of the coming grid upgrade must be built to serve remote wind and solar plants. Moreover, federal regulators actually agree with you that the beneficiaries of such new facilities should bear the costs in rates. Those benefits can nevertheless be widespread and powerful, like those of the highway system.

Your jeremiad against the Federal Energy Regulatory Commission’s Order 1000 sides against the market competition among all electricity resources that transmission facilitates, and favors the continued Balkanization of wholesale power markets and an industry model that belongs more to post-World War II America than to the 21st century. The president, the American Society of Civil Engineers and the Bipartisan Policy Center aren’t promoting greater investment in our inadequate electric infrastructure for no reason. They, too, are concerned about the pocketbooks of electricity customers, not just tomorrow but 20 and 30 years from now.

James J. Hoecker

Husch Blackwell LLP


Mr. Hoecker is a former chairman of FERC and is counsel and adviser to the Working Group for Investment in Reliable and Economic Electric Systems.

Thoughts from a Post-Rocky Mountain Clean Energy Transmission Summit World

The Rocky Mountain Clean Energy Transmission Summit is behind us and what an event it was! Headlined by an impressive host of public and private sector leaders, journalists, and other energy and transmission experts, over 100 attendees participated in our Denver summit.

Owing to a remarkable array of perspectives and experiences, conversations covered many issues, offering unique solutions to though problems.

But one message seemed to carry over the rest—a message that moderator and Senior Editor at High Country News wrote about later in his article, Transmission: the missing link in the renewables revolution.

In the critical context of climate change and renewable energy, the argument for transmission is as follows: in order to cut carbon to the level we must by 2050, we need 100,000 MW of renewable power. That necessitates at least 25,000 miles of new high voltage transmission. In other words, we need enough transmission to cross the country, going east-west, over 9 times. But those wires are not easy to put up. In fact regulators, nationally, regionally and locally can make putting up transmission a long and difficult process, despite being easier than it has been in years past as a result of FERC Order 1000.

On top of all that, to connect renewables—which often are located in rural areas—to urban centers you need to put up transmission, transmission must be built to cross those rural areas. Often, that means going through the wilderness. And that has turned many environmentalists, who would otherwise support the infrastructure that is needed for renewable power, against it.

And there are many other groups who have their own issues with new transmission.

So this is the task at hand: to find a way to address complex regulation and the concerns of all those affected by new transmission so that we can find a way to build the infrastructure needed to avoid the worst effects of climate change.

As one can see, this is exactly why getting stakeholders in the same room as experts who represent many backgrounds—from government to contractors to environmentalists—is critical to progress.

In that vein, we’d like to extend a massive thank you to our sponsors, speakers, moderators, and attendees who made the Denver event a great one.

We hope that you’ll be able to join us at our next event. Stay tuned.


It’s All Connected – Regional Transmission Planning in the Southeast

Cross-posted from AOL Energy, published 11/13/12.

It’s All Connected – Regional Transmission Planning in the Southeast
by Bill White

More than two weeks have passed since Hurricane Sandy brought the Eastern Seaboard to a standstill. Although life is slowly returning to normal, Sandy joins a long series of painful reminders of how dependent 21st century America is on reliable electricity: it powers nearly every facet of our lives. The potential silver lining in the wake of Sandy’s devastation is the influx of interest in our outdated and inadequate transmission grid, highlighting long ignored issues from the benefits of buried transmission lines to the importance of an integrated, redundant, resilient grid – built to withstand even Sandy’s fury.

A robust and modern electric grid is also essential for taking advantage of America’s unmatched renewable energy resources. Wind and sunlight cannot be delivered to customers from their best sources – mostly remote areas and offshore – using railcars and pipelines like coal, oil, and gas; they need transmission lines. In the Southeast, where wind and solar are relatively scarce, transmission lines are critical for bringing cheap and abundant renewable resources from other regions. The Tennessee Valley Authority (TVA), which provides power to nearly all of Tennessee and other Southeastern areas, is now importing wind power from eight wind farms in the Midwest. Alabama Power, a subsidiary of Atlanta-based Southern Company, last year made one of the largest wind purchases ever from producers in Oklahoma.

Several changes under way promise to accelerate the nascent interregional “trade” in cheap renewable energy. Dozens of outdated and inefficient coal plants across the Southeast will be shutting down over the next several years as new air pollution rules take effect; businesses and consumers are demanding more clean energy; and vehicle electrification is growing rapidly, especially in the Southeast. Nearly three percent of electric vehicles sold in the United States this year were registered in Tennessee. Not coincidentally, almost all of these were Nissan Leafs – soon to be manufactured at a plant in Smyrna. But electric vehicles are only as green as the power plants that charge them, and in the Southeast today, coal generates about half of the electricity. How the region invests in transmission will largely determine whether the power from retiring coal plants will be replaced by renewable resources.

A new planning framework unveiled last year by the Federal Energy Regulatory Commission, Order 1000, asks utility transmission planners to work together to solve the transmission challenge across large regions by avoiding duplication and building only those upgrades needed to strengthen the grid, improve reliability, increase efficiency, and integrate large amounts of renewable energy.

Additionally, Swiss engineering firm ABB Group announced a technological breakthrough last week that could solve the problem of transmission losses over very long distances. ABB’s new circuit breaker for high-voltage DC lines – far more efficient than AC lines over long distances – will allow large amounts of renewable electricity to be delivered over thousands of miles, for instance, from Iowa to Tennessee.

Americans have always responded to crises by replacing what was lost with something better, stronger, and smarter: building an even stronger foundation for future growth and prosperity. Let’s not wait for the next Sandy to modernize our electric grid – our most important infrastructure investment for the future of the Southeast – and the nation.

Bill White is a Senior Vice President at David Gardiner & Associates, with more than fifteen years of managing public-private partnerships advancing action on energy and climate change.