SPECTRUM: China Stumbles on Path to Solar Thermal Supremacy

In the final days of 2018 a 100-megawatt solar thermal generating station capable of running around-the-clock, 365-days-a-year connected to the Northwest China regional power grid. It was a race against time to commission the plant in temperatures as low as -20 celsius—and one that plant designer and builder Beijing Shouhang Resources Saving Co could not afford to lose.

“We must finish on time. Otherwise we may face a heavy financial problem,” says Chen Han, Shouhang’s director for international markets.

Shouhang was racing to beat the Chinese government’s December 31, 2018 deadline to secure a guaranteed price for the plant’s power. The deadline was part of an aggressive demonstration program launched in September 2016 to slash the cost of solar thermal power and catapult Chinese firms to the head of the global pack—much as China did with solar photovoltaics.

Alas, a little more than two years later, China has stumbled on the path to solar thermal supremacy. While Shouhang’s and two more of the program’s 20 approved projects met the deadline, four others were cancelled last year and the remaining 13 projects are in limbo.

Solar thermal plants are a potentially crucial power source for global grids as they add more wind and PV solar. Unlike their weather-dependent cousins, solar thermal plants can efficiently store heat and then raise steam for their turbine-generators at will. They can thus dispatch power when it is needed most, reducing grid reliance on conventional gas, diesel and coal-fired generators.

However, the technology is comparatively costly and thus growing slowly relative to PV and wind. The technology took a public relations hit back in 2014 when birds killed by intense solar flux at the largest U.S. plant sullied solar thermal’s eco-friendly image. China’s program has been viewed as an opportunity to put solar thermal technology back on track, but the delays and cancellations mean it will fall far short.

The government anticipated adding 5.3 gigawatts by 2022—more than has been installed to date worldwide since the technology’s debut in the 1980s. Adding six more facilities that have a shot at starting this year would bring China’s total to just 550 MW, according to the Beijing-based Du Fengli, the Alliance’s secretary general. Two years from approval to completion was too short since most projects targeted high-altitude desert regions in China’s Northwest, a region with fantastic solar resources that also experiences long, punishing winters that limit outdoor construction to as few as  months.

Du adds that many players were trying to jump into solar thermal energy without prior experience building an entire plant, let alone one of commercial scale. The three projects that met the deadline are the exceptions that prove that rule.

SUPCON Solar and nuclear power giant China General Nuclear Power eachcompleted 50-MW plants in Qinghai province late last year, and both had operated pilot plants there since as early as 2009. Their plants use different approaches: CGN’s ‘trough’ plant employs mirrors to concentrate sunlight on glass tubes, while SUPCON’s ‘power tower’ uses heliostat mirrors to focus solar energy on a central receiver.

Shouhang, meanwhile, erected its own ¥3-billion power tower plant on the southwestern edge of the Gobi Desert in Dunhuang, in Gansu province, adjacent to a 10-MW plant that it began building in 2014.

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Heliostats at Shouhang’s 100-MW solar thermal power plant in Dunhuang. Credit: Shouhang

In a bulletin announcing the 100-MW plant’s startup Shouhang likens it to, “a silver sunflower blooming on the Gobi.” A field of 11,935 heliostats—each up to 115.5-square-meters across—illuminate a 260-meter-high tower where the energy heats a mix of molten nitrate salts. Tanks hold enough hot salt to operate the plant’s steam turbine for 11 hours, enabling continuous power output with or without sunlight. 

Shouhang’s core business is heat transfer devices, so it was able to develop and manufacture the bulk of the plant’s solar equipment in-house, according to Chen. The firm also learned a lot from operating the pilot plant. “We have very complete experience,” he says.

Chen says the new plant is completing tests mandated by grid operator State Grid Corp. of China before it can enter regular operation. He says that so far no one has observed dead birds around the tower. That’s as expected, he says, since the site is not frequented by many birds and is not along a migratory bird flyway.

Shouhang helped build CGN’s plant and is under contract to build others. It has also taken over another 100-MW power tower project in Gansu whose developer backed out last year. But Chen says those opportunities are on hold because the power price for further plants has not been set. Such uncertainty makes it difficult to secure financing for future projects.

Du at the Alliance says the rates will be less than the ¥1.15 ($0.17) per kilowatt-hour secured by the first three projects. She says officials have indicated they will be ¥1.14 for plants completed this year and ¥1.10 for those starting up in 2020 and 2021, but the government has yet to put those prices in writing.

Much hangs in the balance as China’s solar thermal developers struggle to sustain the anticipated build-out. Recent modeling from Beijing-based Tsinghua University suggests that solar thermal power plants can slash the cost of managing variable wind and solar power. For example, they found that replacing 5-20 percent of Gansu’s planned wind and solar PV generation with solar thermal plants would provide flexibility worth 24-30 cents per kilowatt-hour to China’s State Grid—a benefit well above the tariff that Shouhang raced to secure.

At the same time, some top solar researchers are warning that Chinese developers promising big cost cuts could pose a risk to the sector. Exhibit A, they say, is a record low 7.3 cent/kwh bid for power from a big plant in Dubai to be engineered and built by power equipment giant Shanghai Electric. “Something is nonstandard in that bid,” cautions Johan Lilliestam, a professor of renewable energy policy at the Swiss government laboratory ETH Zürich in a recent publication from the Paris-based International Energy Agency.

Robert Pitz-Paal, who chairs an IEA solar thermal research program, stated in the same report that “unseasoned Chinese firms” will hurt the technology’s global standing if they can not deliver: “If they fail, this may become the coffin nail for the technology as the confidence of clients in CSP and its potential for cost reduction may be damaged strongly by Chinese suppliers.”

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

China Crushes Transmission Records

China’s primary grid operator has energized its biggest and most powerful line yet, a 1.1-million-volt direct current (DC) behemoth that crushes world records for voltage, distance and power. The new ultra-high voltage DC (UHVDC) line built by Beijing-based State Grid Corporation of China can move enough power for 50 million Chinese households, according to a statement issued in Chinese by State Grid last week — 50 percent more than the 800-kilovolt UHVDC lines that State Grid has built over the past decade.

The new 1100-kv UHVDC line absorbs the grid’s alternating current at an AC/DC converter station near the capitol of Xinjiang—China’s vast northwestern territory—and sends DC power to a second converter station in Anhui province in eastern China. That 3,293 kilometer run extends power transmission’s distance record by over 900 kms.

State Grid dubs it the “Power Silk Road” in its statement because it follows the eponymous ancient route’s path through northwest China’s Hexi Corridor and can replace the equivalent of 25,000 coal trains’ worth of coal-fired generation in China’s heavily polluted eastern cities. In addition to battling air pollution, it could also deliver a hefty reduction in greenhouse gas emissions if State Grid prioritizes export of the northwest’s abundant solar and wind power. Continue reading “China Crushes Transmission Records”

SPECTRUM: Energy-Gobbling Cryptocurrency Redux

A little over a year ago I took apart the cryptographic arms race that makes Bitcoin such a massive energy hog. For their January 2019 issue IEEE Spectrum asked me to follow up by profiling Ethereum, Bitcoin’s younger cryptocurrency cousin, which used roughly as much electricity as Iceland for most of 2018. The resulting feature explores the implications of Ethereum’s heavy energy footprint and the Ethereum community’s ambition to prove out a better way to secure global transactions. 

I was pleasantly surprised by the candour of Vitalik Buterin, the Russian-Canadian computer scientist who invented Ethereum when he was just 18. “Criminal” and “a huge waste of resources” are how he described the power-hungry ‘Proof of Work’ distributed security scheme that underpins most cryptocurrencies — including Bitcoin and Ethereum. Even in raw economic terms, Buterin ventured that his brainchild’s economic contributions “look unfavourable” next to the “millions of dollars being burned” to sustain Ethereum.

By the end of this year Buterin and his fellow travellers expect to be implementing an alternative security scheme (‘Proof of Stake’). Ultimately, vows Buterin, they will slash Ethereum energy use by over 99 percent.

China’s Nuclear Power Death Watch

BNEF 2018 China LCOE chart
In China, Nuclear’s Up & Renewables are Down. Graph of levelized cost of energy from new power plants in China in US$ per MWh via Bloomberg NEF 2018.

How many times have you read an article and discovered that the label on the package didn’t match the meat? Here’s an open secret from the news biz: that story’s writer may have also cringed. Writers often don’t see the headline until it runs, and we’re not always ecstatic about the angles editors choose to hook eyeballs.

Take this headline that topped a story today on China’s nuclear power sector in Technology Review magazine:

China’s losing its taste for nuclear power. That’s bad news.

Personally I’d call China’s anti-nuclear turn “sad” rather than “bad.” But what do I know? I only wrote the story!

Whatever the headline, my article shows that the same woes killing Western nukes now confront the technology in China. As the editors’ spot-on subhed puts it: ‘Once nuclear’s strongest booster, China is growing wary about its cost and safety’.

The coming downturn is hard to recognize amid a flurry of new reactor startups, and nuclear industry players worldwide have been slow to acknowledge it. It means that China’s planners may no longer count on reactor power to wean the world’s leading greenhouse gas emitter off of coal and oil. And if one big option for decarbonizing energy systems may be biting the dust, that puts more pressure on the remaining options (eg. solar panels and wind turbines) and on innovators conjuring up new options.

As for whether dropping the nuclear option is bad or sad? I’d prefer to let the readers decide. Have your own look online, or pick up Technology Review’s January 2019 Special Issue on China.

U.S. Deep-Sixes Plutonium Fuel Plant

The U.S. Department of Energy (DOE) has terminated construction of a facility designed to transform 34 metric tons of surplus military plutonium, enough for about 17,000 nuclear weapons, into fuel for nuclear power plants. The Aiken, South Carolina project began in 2007 and was at least $2.6-billion over its $4.9-billion estimated cost and still years from completion — akin to the troubled pair of Westinghouse AP1000 nuclear reactors under construction in nearby Vogtle, Georgia and another pair killed last year at South Carolina’s VC Summer plant.

Mismanagement is only half the story, however, according to Edwin Lyman, a physicist and nuclear expert at the Union of Concerned Scientists in Washington. Lyman says the plant was also plagued by safety, technology and regulatory challenges specific to handling plutonium. Trace amounts of plutonium cause lethal cancers and its 24,110-year half-life means small releases could render lands uninhabitable for generations making it an attractive material for would-be makers of ‘dirty’ bombs. Continue reading “U.S. Deep-Sixes Plutonium Fuel Plant”

Making Power Grids 100 Percent Renewable

nsc_20180609-152x200Just a few  decades ago many experts fretted that variable power from wind turbines and solar panels would destabilize power grids. Today they’re debating the feasibility of 100 percent renewable power, which appears to be the most likely route to decarbonized energy systems by mid-century and thus our best shot at avoiding truly extreme climate change. Two of my recent feature articles explore what running grids on 100 percent renewable energy will take. My June cover story for NewScientist assesses the big picture, identifying the changes required in consumer behavior and power supplies and the technologies available to deliver them. My feature for Scientific American, meanwhile, takes a deeper dive into power grids, and how weather smarts must be built in to make the most of weather-driven “fuel” such as winds and sunlight. Both articles are behind paywalls online. One more reason to consider subscribing to two of the world’s top science magazines!

Double Milestone for Safer Reactors

Call it the world’s slowest photo finish. After several decades of engineering, construction flaws and delays, and cost overruns—a troubled birth that cost their developers dearly—the most advanced commercial reactor designs from Europe and the United States just delivered their first megawatt-hours of electricity within one day of each other. But their benefits—including safety advances such as the AP1000’s passive cooling and the EPR’s airplane-crash-proof shell—may offer too little, too late to secure future projects.

Continue reading “Double Milestone for Safer Reactors”