Caffeine Cranks Up Solar Cells

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

Spectrum: China’s Ambitious Plan to Build the World’s Biggest Supergrid

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

Scientific American: Europe Stores Electricity in Gas Pipes

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

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. Continue reading “SPECTRUM: China Stumbles on Path to Solar Thermal Supremacy”

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!

Power Vaults a Contentious Border

Relations between the United States and Mexico are strained as President Donald Trump pushes his promised border control wall and demands a U.S.-favored rewrite of the North American Free Trade Agreement (NAFTA). But Mexico and the southwestern states that border it continue building an international agenda for electricity. The region’s power players plan to complete a first set of projects before Trump’s term is up that will make the border far more electrically-porous.

Continue reading “Power Vaults a Contentious Border”

Floating Turbines on the High Seas

The world’s first wind farm employing floating turbines is taking shape 25 kilometers off the Scottish coast and expected to begin operating by the end of this year. Atmospheric scientists at the Carnegie Institution for Science argue that the ultimate destination for such floating power farms could be hundreds of kilometers out in the open ocean. Their simulations, published today in the Proceedings of the National Academy of Sciences, show that winds over the open ocean have far greater staying power than those over land.

Continue reading “Floating Turbines on the High Seas”