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.


Rooftop Solar is Great, But the Grid is the Real Key to Giving Everyone Clean Power

Bill McKibben (“Solar Power for Everyone,” June 29th) is right that cheap solar energy is hopeful news for the climate, but no one should conclude that it will render our integrated electric grid or the utilities that own and operate it obsolete.  Energy efficiency and rooftop solar are essential, but expanding the grid to tap remote but rich wind and solar resources is the fastest and cheapest way to remove carbon from electricity.

Nearly all of America’s solar and wind power is purchased today by utilities from large scale facilities connected to the grid, with good reason: utility-scale solar farms produce electricity at half the cost of small rooftop systems.  Wind economics are only compelling at large scale and with large groups of turbines, not as distributed resources.   Almost every household in America with solar panels – including the Borkowskis – still gets most of its electricity from large regional power grids.

Transmission networks are also much more efficient than batteries at smoothing out the natural variability of wind turbines and solar panels.  Grid engineers now blend wind and solar from sources scattered over thousands of square miles into steady and reliable power.  It turns out that the sun is shining or the wind blowing someplace almost every hour of every day – the key is having a network capable of collecting that energy and delivering to where it’s needed.

The ability of transmission to accelerate renewable energy deployment is a fact supported by a mountain of real world evidence, not speculation about future breakthroughs.  Texas built transmission to develop its immense wind resources and is now home to one fifth of the nation’s wind energy.  Large scale wind and solar facilities connected by California’s Renewable Energy Transmission Initiative are much more important than rooftop solar to achieving the state’s 33% by 2030 renewable energy target.  In both cases, transmission investments are paying for themselves quickly by delivering renewable energy to customers at net savings.  Mark Jacobson at Stanford University recently showed 100 percent renewable energy by 2050 to be technically and economically feasible in all 50 states; more than ninety percent of the energy he would have us call on is grid-connected wind, solar, and hydropower.

We share Mr. McKibben’s optimism that we can provide everyone, everywhere with affordable carbon free energy in time to avert a global climate catastrophe; but only if we use ALL of the resources at our disposal, especially the grid.

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.

solar panel

Solar Soars, but for How Long?

Great news for the nation’s solar industry. The Solar Energy Industries Associated (SEIA) in conjunction with GTM released a report this week showing growth in the solar industry at its second-highest level ever. The report quantified new U.S. solar installations during the second quarter of 2012 with 742 megawatts (MW) of solar power installed – a 45% increase over the first quarter of the year. However, SEIA cautions the growth could begin to slow next year in response to various factors including legislative uncertainty.

The data showed utility photovoltaic (PV) market will remain strong through the last two quarters of 2012 with an additional 1.1 gigawatts to come online before the year’s end. The second quarter of 2012 was the largest quarter ever for utility PV installations, with more than 20 projects completed, totaling 447 MW.

Utility scale solar projects are certainly soaring and have attracted the support of many investors, including billionaire trend watcher Warren Buffett. Last year Buffett invested in the Agua Caliente solar project – the world’s largest operational solar PV project – located 65 miles east of the city of Yuma on the former White Wing Ranch in Arizona.

The project is expected to contribute 290 MW of new capacity to the grid, creating enough energy to power between 56,000-100,000 U.S. homes. The project announced it connected 250 MW of grid-connected power. Utility scale projects will continue to grow in capacity, and with them grows the need to modernize our nation’s grid to accommodate newer, diverse sources of energy that can maintain system reliability, increase efficiency and broaden consumer choices.

SEIA’s Report by the Numbers

  • Utility solar: SEIA reports that utility installations hit 477 MW in the second quarter, with eight states (California, Arizona, Nevada, Texas, Illinois, North Carolina, New Mexico, and New Jersey) posting utility installations of 10 MW or greater. In total, the U.S. now has 5,700 MW of installed solar capacity, enough to power nearly one million households.
  • Residential solar: During the second quarter, the U.S. residential solar market grew with the installation of 98.2 MW, led by California, Arizona, and New Jersey.
  • Non-residential solar: In contrast, non-residential (commercial, government, non-profit) installed 196 MW during the second quarter, after installing 291 MW in the first quarter of 2012.
solar panel

ACEG’S Bill White Speaks at Today’s Arizona Solar Summit

The 2012 Arizona Solar Summit kicks off in Phoenix, Arizona this morning. The event will convene CEOs from the renewable energy and clean tech industries, state public utilities commissioners, and transmission experts and developers to discuss the legal and policy structures necessary to make the state a “solar hub” for the region. Check out the full conference agenda here.

ACEG’s own Bill White will today speak to how transmission is key to realizing the region’s clean energy future during the 2:45 PM panel today titled “A solar super hub in the Southwest: Imagining Arizona and surrounding states as the exporters of solar energy to the rest of the nation.”

This panel will envision a future in which the Southwest is propelled to a solar future by a national transmission overlay or a national REC market, becoming both a hub for utility scale solar as well as a region rich in distributed generation. Panelists will address what policies and market changes would be required for this to occur.

Bill will be joined on the panel by:

  • Vijay Vittal, Professor, Ira A. Fulton Chair Professor in Electrical Engineering, Ira A. Fulton School of Engineering, ASU, and Director, Power System Engineering Research Center
  • Peter Esposito, Senior Vice President and Chief Commercial Officer, Tres Amigas
  • Keith Sparks, Director of Development, Centennial West Clean Line Energy
  • Bill White, Senior Advisor, Americans for a Clean Energy Grid
  • Craig Robb, Senior Vice President, National Bank of Arizona, and Managing Director, Zions Energy Link

Tomorrow at 9:00 AM, FERC Chairman Jon Wellinghoff will discuss how the federal government is working to help the Southwest develop its solar potential during the “Future Promise of Solar Energy” Keynote address.

The Summit is being hosted by the Sandra Day O’Connor College of Law at Arizona State University with sponsorship support from Americans for a Clean Energy Grid.

solar panel

ACEG Team to Participate in Arizona Solar Summit

Americans for a Clean Energy Grid is headed to Arizona later this month for the 2012 Arizona Solar Summit.

Hosted by the Sandra Day O’Connor College of Law at Arizona State University, the Phoenix event will convene CEOs from the renewable energy and clean tech industries, state public utilities commissioners, and transmission experts and developers March 26 and 27 to discuss the legal and policy structures necessary to make the state a “solar hub” for the region.

Check out the full conference agenda here. Highlights include a keynote from FERC Chairman Jon Wellinghoff where he’ll discuss how the federal government is working to help the Southwest develop its solar potential.

ACEG’s own Bill White will speak to how transmission is key to realizing the region’s clean energy future as part of a panel with Peter Esposito, Senior Vice President and Chief Commercial Officer of Tres Amigas, and others.

The Summit will also include a “Solar CEOs Roundtable,” where leaders of America’s top solar companies will discuss the major issues facing their industry in 2012.

Stay tuned for more details about the event!

solar panel

Investing in our Solar Future

In a sign of confidence in the future of the American renewable energy market, one of the country’s top investors, Warren Buffet, is betting big on solar.

Buffet’s power company, MidAmerican Energy Holdings, recently announced that it will acquire a 49% stake in a 290MW Arizona solar project, part of the company’s move to “aggressively pursue” expansion in the renewable energy sector.

Word of the NRG project followed an announcement a few weeks ago that MidAmerican plans to buy a huge, 550 MW solar PV plant planned for California – the Topaz project.

Greg Abel, chairman, president and CEO of MidAmerican Energy Holdings Company had this to say:

“As energy needs continue to increase, the Topaz project will allow MidAmerican to produce renewable energy for thousands of Californians. This project also demonstrates that solar energy is a commercially viable technology without the support of governmental loan guarantees and reflects the type of solar and other renewable generation that MidAmerican will continue to seek to add to its unregulated portfolio.”

Solar is indeed commercially viable. And we need the transmission grid that is designed to support it. There is vast solar potential, from California to New Jersey, Wisconsin to Hawaii, and in many states in between. To unlock that potential and support projects like the Topaz solar plant, we have to connect them to consumers.

Read more about how transmission helps grow domestic clean energy supplies.

solar panel

Conservation Law Foundation: “Clean Energy Solutions Needed: Small, Medium, Large and Extra Large”

Industry leaders have expressed a variety of opinions regarding the size of various clean energy projects that should drive development of this market. However, Seth Kaplan, VP for Policy and Climate Advocacy at the Conservation Law Foundation, asserts that we need to create both a vast network of distributed solar on millions of rooftops as well as smart development of large solar. Additionally a wide array of technologies will be needed to address global warming for all buildings types, sidewalks to allow safe travel on foot, shareable bicycles, renewable energy powered electric cars, trains that connect cities and neighborhoods, and intelligently sited wind farms and solar installations on and off-shore.

In addition to searching for new solutions, we need to recognize the ones that warrant phasing out such as old nuclear power plants that have safety issues and have proven to be expensive. Solar electric generation, on the other hand, holds a lot of potential as the price continues to descend at a steep rate: it creates many new opportunities to deploy solar electric generation on a variety of scales, including large – and sometimes extra large – scale solutions on land as well as small and medium scale solutions on rooftops.

To read the article, click here: http://www.clf.org/blog/clean-energy-climate-change/clean-energy-solutions-needed-small-medium-large-and-extra-large/