Rumble Royale: Can the U.S. Grid Work With 100% Renewables?

Four Days in 2055: Dynamic heat and power supply in the mid-century wind, water and sunlight-fuelled Continental U.S. simulated by Stanford’s Mark Jacobson. Credit: ASU/PNAS

A battle royale between competing visions for the future of energy blew open today on the pages of a venerable science journal. The conflict pits 21 climate and power system experts against Stanford University civil and environmental engineer Mark Jacobson and his vision of a world fuelled 100 percent by renewable solar, wind, and hydroelectric energy. The criticism of his “wind, water and sun” solution and an unapologetic rebuttal from Jacobson and three Stanford colleagues appear today in the Proceedings of the National Academy of Sciences (PNAS).

The critics enumerate what they view as invalid modeling tools, modeling errors, and “implausible and inadequately supported assumptions” in a projection of the mid-century U.S. energy supply that Jacobson and his coauthors published in PNAS in 2015. “The scenarios of [that paper] can, at best, be described as a poorly executed exploration of an interesting hypothesis,” write the experts, led by Christopher Clack, CEO of power grid modeling firm Vibrant Clean Energy.

Clack says their primary goal is accurate science, the better to equip policymakers for critical decisions: “We’re trying to be scientific about the process and honest about how difficult it could be to move forward.”

The text and statements by Clack’s coauthors question Jacobson’s evaluation of competing energy technologies, and specifically his rejection of two non-renewable energy options: fossil fuel power plants equipped to capture their own carbon dioxide pollution and nuclear reactors.

Jacobson calls Clack’s attack, “the most egregious case of scientific fraud I have encountered in the literature to date.”

In fact, while both sides claim to be objectively weighing the energy options, the arguments and backgrounds of the protagonists belie well-informed affinities for various energy sources (and informed biases against others). As sociologists of science would say, their choice of data and their reading of it reflects hunches, values, and priorities.

Consider Clack’s coauthor Ken Caldeira, a climate scientist at the Carnegie Institution for Science. Caldeira’s press release broadcasting their critique argues that removing carbon dioxide from the U.S. power supply is a massive job demanding the biggest tool box possible: “When you call a plumber to fix a leak, you want her to arrive with a full toolbox and not leave most of her tools at home,” says Caldeira.

The same document then abandons this technology-agnostic tone to call out nuclear energy and carbon capture as technologies that “solving the climate problem will depend on.” And Caldeira has appealed for deploying a new generation of nuclear reactors which he and other nuclear boosters such as former NASA scientist Jim Hansen say are needed because renewables “cannot scale up fast enough.”

They could be right. Then again, expert sources they cite, such as the International Energy Agency, have consistently underestimated renewable energy growth. And identical scale-up critiques have also been well argued against nuclear energy and carbon capture and storage (CCS).

Jacobson makes some powerful arguments for walking away from those technologies in his PNAS papers. Nuclear liabilities cited by Jacobson include the threat of future Fukushima-like disasters, nuclear weapons proliferation facilitated by large-scale uranium enrichment, and the financial risks such as those that recently bankrupted Westinghouse. And, as he notes in his rebuttal, the International Panel on Climate Change has determined there is “robust evidence” and “high agreement” among experts validating these nuclear risks.

Jacobson’s rejection of CCS technology, meanwhile, may provide deeper insight on what makes him a magnet for academic attacks.

The main thing that soured Jacobson on CCS was his own pioneering work on the climate change impacts of black carbon, or soot. Fossil fuel plants that capture most of their CO2 still release soot that’s both a public health menace and an agent of climate change. In a 2001 paper in Nature on simulations of soot particles in the atmosphere, he controversially argued that soot in the air and on blackened snow and ice fields absorbs enough heat to make its climate impact second only to CO2. Sixteen years on, that view now enjoys strong support from the science community.

Jacobson subsequently turned his science on black carbon into political activism, helping to convince California regulators to deny low-carbon incentives to so-called “clean diesel” technology. A decade later that tech is in disarray—sullied by scandals over fraudulent tailpipe cleanup claims. European automakers long reliant on diesel technology are now abandoning it in favor of hybrids, as IEEE Spectrum reported in April.

His style, however, has not necessarily made him popular among climate scientists. Drew Shindell, a climate modeler at Duke University, describes Jacobson as a brilliant scientist with an unusual go-it-alone style that alienates some researchers.

Whereas most climate models are honed by large teams, composed of hundreds of scientists, Jacobson single-handedly constructed the GATOR-GCMM climate model that underpins his work—including the 2001 Nature and 2015 PNAS reports. Shindell says other climate models are also shared more freely and subject to much more independent validation than Jacobson’s. So when he claims that “his model is more complex and therefore better,” says Shindell, it “rubs people the wrong way.”

To Shindell, however, Jacobson’s outspokenness and solo style do not invalidate his work. In fact, he argues that raising important questions is Jacobson’s greatest contribution: “His work does prompt people to really look closely. That’s also a service to the community.”

Could something similar be playing out now in PNAS? Power experts can bristle at outsiders who offer novel approaches to their problems. In 2004 Spectrum profiled mathematical modelers—a power engineer and a pair of plasma physicists—who were drawing heavy fire for the unorthodox prediction that big blackouts are inevitable. That trio (Ian Dobson, Benjamin Carreras, and David Newman) endured years of derision and saw their research funding pulled. They ultimately triumphed by all but predicting the Southwest blackout of 2011, a story I documented for Discover magazine last year.

Jacobson and his PNAS coauthors similarly crafted their own unorthodox energy model—LOADMATCH—which sets a bold vision. While their critics mostly model power grids, Jacobson’s team used LOADMATCH to map out a 100-percent-renewable route to meeting all major energy needs in the Continental United States. The model replaces fossil fuels for heating and transportation with renewably-generated hydrogen and electricity, thereby tackling nearly all greenhouse emissions from fossil fuels rather than just the 35 percent from power plants.

Mark Jacobson. Photo: L.A. Cicero

The weakest point in Jacobson’s 2015 paper identified by his critics is a heavy reliance on hydropower plants, which serve as his simulated power grid’s backstop energy supply during long periods of weak sun and becalmed winds. This jumps out in the graph [above], which simulates total continental U.S. heat and power generation over four days in January 2055. Hydro turbines ramp up heavily each day after the sun sets, delivering as much as 1,300 gigawatts at their peak—a level that implies a 15-fold expansion in hydropower generating capacity.

Jacobson says the LOADMATCH code adds turbines to existing hydropower dams as required to prevent power outages. The reservoirs are untouched, and thus store the same amount of energy. But that energy is concentrated into those hours of the year when no other power source is available.

However, no such expansion is documented in the 2015 paper. Critic-in-chief Christopher Clack argues that it is a modeling error because, according his analysis, adding the required turbines at existing dams is not physically possible. And even if it were, he says, discharging the hydropower as described would impose unacceptable impacts on aquatic ecosystems and downstream water users. Invalidating that option, says Clack, means Jacobson’s scheme will cause blackouts: “The whole system breaks down.”

Jacobson admits the 2015 paper was “vague” on the hydropower upgrade but stands by its technical and economic viability. The environmental impacts, he says, reflect a cost that policymakers pursuing his roadmap would need to consider. All clean energy solutions will require tradeoffs, says Jacobson, noting that the low-carbon grid projection that made Clack’s reputation, a 2016 report in Nature Climate Change, calls for a much larger build-out of unpopular powerlines.

Jacobson also has alternative sources of backup power, such as adding turbines to more rapidly convert stored heat from solar thermal power plants into electricity. “We could increase [their] discharge rate by a factor of 3.5 to obtain the same maximum discharge rate of hydro, without increasing the [solar thermal plants’] mirror sizes or storage,” he says.

If you’re wondering where battery storage figures in all of this, it is yet another option—though one that both Jacobson and Clack deemed unnecessarily costly in their respective studies. Clack’s 2016 projections relied mostly on flexible natural gas power plants rather than dams or batteries to handle residual power demand—delivering a 78 percent reduction of power sector carbon emissions from 1990 levels by 2030 [see map below].

What is certain, from the darkening findings of climate science, is that climate change calls for a bold remake of the global energy system of the sort that both Clack and Jacobson have championed. Their respective visions certainly appear to have more in common than ever as the Trump Administration seeks to turn back the clock on grid engineering.

The U.S. power sector is bracing for the release of a power grid study ordered by President Trump on whether renewable energy installations degrade grid reliability by undermining continuously operated “baseload” nuclear and coal power plants. U.S. Energy Secretary Rick Perry’s memo commissioning the study states as fact that “baseload power is necessary to a well-functioning electric grid.”

Last week, the Rocky Mountain Institute’s Mark Dyson and Amory Lovins called out that “curious claim,” which they say, “has been thoroughly disproven by a diverse community of utilities, system operators, economists, and other experts that moved on from this topic years ago.” What the grid needs, they write, is flexibility, not baseload power plants.

The power industry is already moving in that direction. For example, flexibility was California utility PG&E’s central argument last year when it announced plans to shut down the Diablo Canyon nuclear plant when its reactor licenses expire in 2024 and 2025. The baseload plant was ill-suited, PG&E said, to help them manage the increasingly dynamic power flowing on California’s grid.

Dyson and Lovins’ prescription for the power grid community, meanwhile, is unity. As they titled last week’s post: “The grid needs a symphony, not a shouting match.”

Chris Clack’s 2016 U.S. power sector simulation slashes CO2 emissions 78% using a DC supergrid and gas-fired power to balance renewable energy. Source: Nature Climate Change

This post was created for Energywise, IEEE Spectrum’s blog about the future of energy, climate, and the smart grid

German Parliament OKs Bold HVDC Grid Upgrade

Germany’s bold transmission plan is a go. The Bundesrat, Germany’s senate, has accepted the plan’s enabling legislation forwarded to it by the Bundestag (Germany’s parliament), according to the authoritative German Energy Blog. There is every reason to expect that the plan’s core element — four high-voltage direct current or HVDC transmission lines profiled by Spectrum last month — will get built.

That is good news for Germany’s grid and those of its neighbors. All are straining to manage powerful and variable flows from the wind turbines and solar panels that provided 12 percent of Germany’s power generation last year.

Elements of both the HVDC system design and the legislation should ease construction of the HVDC systems. On the design side, Germany’s transmission system operators have specified advanced converters whose ability to arrest and clear DC line faults will reduce the risk of running overhead lines. This means the HVDC lines can use existing rights-of-way used by AC lines. In fact, they can be hung from the same towers. Read the May 2013 story for extensive discussion of the advanced modular multilevel converters.

The enabling legislation, meanwhile, will simplify line permitting by making a federal court in Leipzig the only forum for legal disputes concerning the projects. Separate legislation passed by the Bundesrat and Bundestag makes  Germany’s federal networks regulator, the Bundesnetzagentur or BNetzA, the sole permitting authority for power lines that cross Germany’s state or national borders. These measures — for better or worse — cut out state-level officials that face greater pressure from local project opponents and may be more sympathetic to their concerns.

Add it all up and Germany is en route to become the first country with HVDC lines playing a critical role at the core of their power grid. It is arguably the first real challenge to AC’s century-plus reign as the top dog in power transmission since DC-advocate Thomas Edison lost the War of Currents. Tesla and Westinghouse may just be rolling over.

This post was created for Energywise, IEEE Spectrum’s blog on green power, cars and climate

Supergrid Technology Beats Expectations

HVDC breaker Source AlstomAn industrial research consortium that is a who’s-who of the European power industry says development of technologies to produce high-voltage DC (HVDC) supergrids accelerated in 2012 — “surpassing expectations.” The assessment comes in the supergrids technology roadmap updated earlier this month by Friends of the Supergrid, whose members include power equipment suppliers such as Siemens, ABB and Alstom, as well as transmission system operators and renewable energy developers.

Summarizing the conclusions of an expert group within the International Council on Large Electric Systems — better known as CIGRE, its French acroynm — the Friends of the Supergrid says there is now no doubt as to the feasibility of HVDC networks ferrying renewable energy resources from wherever they are in surplus to wherever they are needed: “CIGRE Working Group B4–52 considered this question, specifically whether it was technically and economically feasible to build a DC Grid, and the answer was yes.” Continue reading

Electrical Upgrade Prescribed for Japan’s Crimped Grid

An advisory body for Japan’s powerful Ministry of Economy, Trade and Industry (METI) has endorsed a tripling of the capacity to pass power between Japan’s otherwise estranged AC power grids: the 50-hertz AC grid that serves Tokyo and northeastern Japan, and the 60-hertz grid that serves western Japan. This frequency divide hascomplicated efforts to keep Japan powered since the March 2011 earthquake and tsunami — a task that keeps getting harder with the inexorable decline in nuclear power generation (at present just one of Japan’s 54 reactors is operating). Continue reading

Mideast Morass Dims Mediterranean Solar Hopes

abbas-sarkozy-and-olmert-at-paris-summit-credit-l-blevennec-elysee-photo-servicePlanning for massive development of North Africa’s solar energy potential became “collateral damage” of the war in Gaza this winter and won’t restart for at least another month, according to French newspaper Le Monde (article en Français).

The 43 countries of the Union for the Mediterranean, which includes Muslim nations such as Egypt and Algeria as well as Israel, adopted solar energy as its keynote project last summer. And last fall the European Commission endorsed the need for a high voltage DC supergrid to share the resulting clean energy with Europe. Planning froze in late December, however, after Israeli tanks rolled into Gaza in response to rocket fire.

Participation of Muslim countries in a development partnership with Israel — a coup for French President Nicolas Sarkozy when he launched the Union for the Mediterranean last summer — became politically untenable as Gaza crumbled.

Continue reading

Nukes, Gas, Oil and Coal All Losers in EU Energy Strategy

The European Commission issued its Strategic Energy Review yesterday, proposing energy efficiency investments, a shift to alternative fuel vehicles to end oil dependence in transport, and more aggressive deployment of renewable energy and carbon capture and storage to “decarbonise” the EU electricity supply. Figuring prominantly among its first six “priorities essential for the EU’s energy security” are the North Sea offshore electric power supergrid that Energywise covered in September and the Mediterranean Ring electric interconnection of Europe and North Africa that I’ve been harping on this week. 

The EC energy strategy not only endorses the MedRing, but views it as a component of a future supergrid traversing Europe and stretching beyond the Mediterranean to Iraq, the Middle East and Sub-Saharan Africa.

How would this new vision (and $100/barrel oil) alter the complexion of European energy consumption? The energy review projects that by 2020 total energy demand drops from the equivalent of 1811 metric tons of oil in 2005 to 1672 MTOE in 2020. Demand met by renewables such as wind, solar and hydro more than doubles in real terms from 123 to 274 MTOE, while their share of total demand leaps from 6.8% to 16.4%. Imported renewables – with the MedRing delivering North African wind and solar power – jump 10-fold from 0.8% in 2005 to 8.8% in 2020.

Oil, gas, coal and nuclear, meanwhile, all see a diminished role, both in real terms and as a share of European energy demand. Interestingly the role of natural gas – the low-carbon fossil fuel – drops the most, from 25% to 21%, reflecting EU concern over dependence on gas imports from Russia. Nuclear’s share drops the least, from just slightly over to slightly under 14% of demand; this assumes that nuclear phaseout plans, particularly Germany’s, are followed through. 

How to make it all come true? Accompanying the EC review is a ‘green paper‘ (the EU’s unbleached alternative terminology for what we’d call a ‘white paper’) outlining a variety of new regulatory and financial mechanisms. The EU is already a world leader in terms of incentives for lower carbon energy with strong price supports for solar and wind and a carbon cap and trade program up and running (though still lacking teeth as my Energywise colleague Bill Sweet notes). However, the energy review warns that the primarily national-level financing that drives energy projects today are inadequate to drive infrastructure that is pan-European or larger. A perfect example is the massive investment in high-voltage dc lines needed to turn the MedRing into a bulk power mover (see the second half of our feature on MedRing: “Closing the Circuit”). 

Even less viable under existing financing mechanisms are those projects that entail considerable “non-commercial risks” such as threats of political instability or terrorism. Did someone say North Africa?

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This post was created for EnergywiseIEEE Spectrum’s blog on green power, cars and climate