Coffee is best served at 85°C — the same temperature used to accelerate endurance tests for electronics. Mere coincidence? Not if you’re a UCLA scientist developing solar cells using a promising new material. (Or a science journalist dishing up the latest dispatch from a world-leading electronic materials lab.) Taste for yourself at Spectrum …
For nearly two weeks last November, smoke from the Camp fire drained 150 miles down the Central Valley and out toward the sea, engulfing Sacramento and the whole Bay Area. San Francisco looked — and breathed — like New Delhi, the world’s most polluted city. Miles away in the mountain town of Paradise, the fast-moving conflagration killed 85 people — making the Camp fire the deadliest wildfire in state history. But pollution research suggests that once heart attacks and respiratory-related deaths are factored in, its soot was even more deadly than its flames. Based on earlier pollution studies, we project that soot from the Camp fire caused about 100 premature deaths just in the San Francisco Bay Area and hundreds more hospitalizations and emergency room visits than normal.
Wind rips across an isolated utility station in northwestern China’s desolate Gansu Corridor. More than 2,000 years ago, Silk Road traders from Central Asia and Europe crossed this arid, narrow plain, threading between forbidding mountains to the south and the Gobi Desert to the north, bearing precious cargo bound for Imperial Beijing. Today the corridor carries a distinctly modern commodity: gigawatts of electricity destined for the megacities of eastern China. One waypoint on that journey is this ultrahigh-voltage converter station outside the city of Jiuquan, in Gansu province.
Electricity from the region’s wind turbines, solar farms, and coal-fired power plants arrives at the station as alternating current. Two dozen 500-metric-ton transformers feed the AC into a cavernous hall, where AC-DC converter circuits hang from the 28-meter-high ceiling, emitting a penetrating, incessant buzz. Within each circuit, solid-state switches known as thyristors chew up the AC and spit it out as DC flowing at 800 kilovolts.
From here, the transmission line traverses three more provinces before terminating at a sister station in Hunan province, more than 2,300 kilometers away. There, the DC is converted back to AC, to be fed onto the regional power grid. The sheer scale of the new line and the advanced grid technology that’s been developed to support it dwarf anything going on in pretty much any other country. And yet, here in China, it’s just one of 22 such ultrahigh-voltage megaprojects that grid operators have built over the past decade.
The result is an emerging nationwide supergrid that will rectify the huge geographic mismatch between where China produces its cleanest power — in the north and west — and where power is consumed in the densely populated east. Moving energy via this supergrid will be crucial to maximizing China’s use of renewable energy and slashing reliance on coal.
Read on at IEEE Spectrum
This month Denmark’s biggest energy firm, Ørsted, said wind farms it is proposing for the North Sea will convert some of their excess power into gas. Electricity flowing in from offshore will feed on-shore electrolysis plants that split water to produce clean-burning hydrogen, with oxygen as a by-product. That would supply a new set of customers who need energy, but not as electricity. And it would take some strain off of Europe’s power grid as it grapples with an ever-increasing share of hard-to-handle renewable power.
Turning clean electricity into energetic gases such as hydrogen or methane is an old idea that is making a comeback as renewable power generation surges. That is because gases can be stockpiled within the natural gas distribution system to cover times of weak winds and sunlight. They can also provide concentrated energy to replace fossil fuels for vehicles and industries. Although many U.S. energy experts argue that this “power-to-gas” vision may be prohibitively expensive, some of Europe’s biggest industrial firms are buying in to the idea.
European power equipment manufacturers, anticipating a wave of renewable hydrogen projects such as Ørsted’s, vowed in January that all of their gas-fired turbines will be certified by next year to run on up to 20 percent hydrogen, which burns faster than methane-rich natural gas. The natural gas distributors, meanwhile, have said they will use hydrogen to help them fully de-carbonize Europe’s gas supplies by 2050…
Read the rest at Scientific American
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. Continue reading “SPECTRUM: China Stumbles on Path to Solar Thermal Supremacy”
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”
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.