Peter Fairley

Return of the Solar Power Tower

Last week Spectrum Online ran my profile of Andasol 1, a solar thermal power plant that’s set to startup in Andalucia with the largest installation built expressly for storing renewable energy: a set of molten salt storage tanks that will hold enough heat energy to run its 50 MW steam turbine for 7.5 hours after dark. This week brought decisive evidence that another solar thermal design that makes even better use of energy storage — a so-called ‘power tower’ whereby sunlight is focused on a central tower — will also have its moment in the Andalucian sun.

The project, dubbed Gemasolar, will employ sun-tracking mirrors covering an area equal to 40 soccer fields to focus light at the top of a roughly 120-meter-high tower. There the sunlight will heat a solar receiver full of molten salt. In contrast, Andasol 1 (like most of the solar thermal plants under construction in the U.S., Spain, North Africa and the Gulf) uses thousands of square meters of trough-shaped mirrors to focus light on a synthetic oil; energy is stored via heat exchangers that transfer the synthetic oil’s heat to a molten salt.

One advantage of the power tower is thus obvious: heating salt directly eliminates the need for heat exchangers, reducing installation and operating costs. Another lies in the fortuitous thermodynamics of heating molten salts, whose maximum safe temperature of 565 C is about 165 C higher than the synthetic oil’s.

Sandia National Lab researchers verified these power tower advantages in the second half of the 90s, but also suffered through a series of operational difficulties. Five years ago the European Commission provided funding for the Gemasolar project (then known as the Solar Tres) to demonstrate that the difficulties could be overcome, but the project foundered on legal issues and changes in Spain’s renewable energy law. But engineering continued and this March the project sprung back to life when its lead proponent, Spanish engineering firm Sener, clinched a solar thermal joint venture with Abu Dabi’s alternative energy program.

With Abu Dabi’s deep pockets Gemasolar’s financing just might survive the current financial crisis. Siemens confirmed that the tower was moving forward this week by disclosing that it would supply the steam turbine to convert the tower’s solar-generated heat into up to 19 MW of electricity for the Spanish grid.

For further details on Gemasolar, see this frank telling of its origins, design and goals on Sener’s website. For details on a competing power tower design that directly produces steam, see this white paper from Spains’ Abengoa Solar.

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

October 10, 2008October 10, 2008 by pfairley

Déjà? Are Hybrids Already Passé?

Plugs are definitely vogue at this week’s Mondial de l’Automobile in Paris. So where does the hybrid vehicle fit into the picture? It may not, according to Renault. The French carmaker says that electric vehicles, not hybrids, are needed to deliver the emissions reductions that governments and customers demand.

Renault says that it is engineering a pair of battery-powered electric vehicles (EVs), to be produced starting in 2011. As I report for MIT Technology Review today, Renault claims these EVs will be cheaper to build, cost markedly less to power, and produce far less carbon dioxide. Today they unveiled a partnership with utility géant Electricité de France to “establish electric cars as a viable and
attractive transport solution for consumers.”

And Renault is not the only major automaker planning to produce commuter-oriented EVs. Mitsubishi Motors and Daimler both announced plans in Paris last week to accelerate commercialization of small EVs — Mitsubishi with its i-MiEV minicar and Daimler with a battery version of its popular Smart Fortwo. Volkswagen’s promo materials in Paris confirmed it would join the EV club, producing a tiny commuter EV called the Up! in 2010 with a top speed of 130 kilometers/hour and roughly 100 kms of range.

Ok you say. EV’s are à la mode. But what of the hybrid option? The question is partly semantic. Hybrid technology is everywhere if you count the mild hybrids, which employ a small but potent electric battery to save gas by rebooting the combustion engine on a green light instead of idling through the red; some can also recuperate energy during breaking by recharging their battery. This technology is going mainstream: Renault competitor PSA Peugeot Citroën said it alone will install 1 million stop-start systems by 2011. VW spokesperson Martin Hube said his company viewed stop-start as just an evolution of internal combustion drive. “You can call it a mild hybrid but it’s just a smart technique,” says Hube. “That’s nothing new.”

No automaker questions whether full hybrids like the Prius or GM’s plug-in Chevy Volt that can drive on either electricity or gasoline are something new. But while several showed full hybrid concept cars in Paris, fewer talked up plans to build one. Perhaps they’ve made the same calculation as Renault: it’s not worth the trouble to cram high-energy motors, batteries and an engine into a vehicle when one can go straight to the full EV instead.

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

October 9, 2008October 9, 2008 by pfairley

Paris Mondial de l’Automobile Flaunts the Plug

Five years ago Toyota relaunched its Prius with a Saatchi & Saatchi ad blitz with the EV-bashing tagline “and you never have to plug it in.” Toyota’s corporate marketing manager said the idea was to show the Prius was, “not an idea that’s ahead of its time.”

What a difference a few years can make. At this year’s Paris Mondial de l’Automobile, which opened to the press yesterday, plug-in hybrids and full-battery EVs are everywhere — and their plugs are displayed conspicuously.

Smart, the Daimler/Swatch joint venture, towered a dangling plug over their floorspace to highlight its development of an EV model of the tiny trendy Smart Car due out in 2010. GM executives gamely held the cord of the Chevy Volt plug-in hybrid for photographers. And check out the plug on Ligier Automobiles’ EV city car!

Frank Weber, GM’s Global Vehicle Line Executive for the Volt, explained the shift to me in dollars and cents, or rather euros and centimes. “If you say that the charge costs less than a euro per day, it’s that simple,” says Weber. “Plugging in means saving, being able to drive and don’t watch the signs at the gas station. This is what the plug means. It’s now looked at as an opportunity and like, well ok at night you have to plug it in but you would do this anytime because the moment you plug it in you know that you save.”

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

October 3, 2008October 10, 2008 by pfairley

Feathered Farmland Friends of the Fens

The wind power industry has had close to zero success designing bird and bat-safe turbines, but nascent research by ecologists nevertheless shows that wind power is compatible with local ecology. Case in point: today’s report in Britain’s Journal of Applied Ecology on wind farms and birds in the East Anglian fens.

Mark Whittingham and fellow ecologists from Newcastle University surveyed birds on farmland around two wind farms in the fens and recorded almost 3,000 birds from 23 different species. Among them are five endangered species: the yellowhammer, the Eurasian tree sparrow, the corn bunting, the Eurasian skylark and the common reed bunting.

Whittingham and company found the wind turbines had no effect on the birds’ distribution with the exception of common pheasants. “This is the first evidence suggesting that the present and future location of large numbers of wind turbines on European farmland is unlikely to have detrimental effects on farmland birds,” says Whittingham.

Plenty of questions remain. For example, a comprehensive $15 million study of Denmark’s large offshore wind farms published last winter showed seabirds to be remarkably adept at avoiding offshore installations, but ecologists remain concerned that the 10,000 megawatts of offshore wind power that Germany hopes to install by 2020 could scare off populations of endangered loons along Germany’s North Sea coast.

Even the Newcastle study was conducted last winter and must be followed up to confirm there are no unexpected impacts during the breeding season.

The wind industry would do well to continue working on newer, safer technology.

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

October 1, 2008October 1, 2008 by pfairley

Physicists Talk Tough on Efficiency and The War

I recall well a meeting of journalists at the Kennedy School of Government in 2003 where I was regarded as a wingnut + conspiracy theorist for seeing a linkage between U.S. intransigence on greenhouse gas controls and the War in Iraq. Never have I felt as alienated as an American intellectual. These days I reflect instead on how far the national conversation has come in the years since. I happened upon the latest sign of hope quite unexpectedly in a report on energy efficiency issued earlier this month by the American Physical Society: “Energy = Future. Think efficiency.”

I’d been feeling guilty about letting the APS report pass by without a mention. Energy efficiency is a tough story for journalists — making do with less energy simply lacks the sex appeal of faster cars or new power generating technologies such as high-tech techniques for pollution-free coal power or the latest in photovoltaics. And yet, as the APS rightly points out, the U.S. is in a better position than most countries to meet its need for clean, domestic energy by squeezing a bigger bang out of every joule of energy consumed.

What will be useful about the APS report is its explicit connection between the technologies available to boost efficiency in the key sectors of transportation and buildings, and the shortcomings in science & technology policy that thwart their ready adoption or rapid adoption.

But what I really appreciated was the no-nonsense manner in which the analysis unfolds. The relatively frank prose of the executive summary (considering the genre) sets the stage for what follows:

“Nowhere is the standard of living more rooted in energy than in the United States, and, with its defense forces deployed in the most distant regions around the world, nowhere is the security of a nation more dependent on energy…Yet only in times of extreme turbulence — the OPEC (the Organization of Petroleum Exporting Countries) oil embargo in 1973, the overthrow of the shah of Iran in 1979 and the Persian Gulf War in 1991 — when public frustration became politically intolerable did American officials devote serious attention to energy policy. Although some of the policy initiatives yielded significant benefits, others were left on the drafting board as the nation reverted to a business-as-usual energy routine once the turbulence passed and public dissatisfaction dissipated.”

How refreshing. Now, let’s get to work.

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

September 29, 2008September 29, 2008 by pfairley

Negative Prices for Clean Power

How do you know that congestion on high-voltage transmission grids is stranding valuable renewable energy? When the price of electricity goes negative. American Wind Energy Association electricity industry analyst Michael Goggin delivers a snapshot of the phenomenon in a recent column for Renewable Energy World.

Goggin points to data from the Electricity Reliability Council of Texas or ERCOT, the state’s grid operator, showing an increasing incidence of generators paying buyers to take their power. According to Goggin, such conditions track the explosive installation of wind farms in West Texas — and are very bad news for their operators.

Prices fell below US -$30/MWh (megawatt-hour) on 63% of days during the first half of 2008, compared to 10% for the same period in 2007 and 5% in 2006. If prices fall far enough below zero that the cost for a wind plant to continue operating is higher than the value of the US $20/MWh federal renewable electricity production tax credit plus the value of other state incentives, wind plant operators will typically curtail the output of their plants.

Worse still, consumers in adjacent areas are paying top dollar for power because the transmission lines between them and the excess wind power are overloaded.

Texas is running into trouble because it pushed wind power harder and faster than other states, but it is also leading the way to address what is really a nationwide problem. This summer the Public Utility Commission of Texas approved a scheme called the Competitive Renewable Energy Zone (CREZ) process to incentivize construction of new transmission lines to evacuate stranded wind power. Earlier this month a consortium of major utilities including MidAmerican and AEP announced their intention to do so.

For a detailed yet accessible look at Texas’ renewable energy transmission challenge and efforts to clear out the bottlenecks, see this overview from the State Energy Conservation Office.

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This post was created for Tech Talk – Insights into tomorrow’s technology from the editors of IEEE Spectrum.

September 26, 2008September 28, 2008 by pfairley

CO2’s Bottom Line Just Keeps On Rising

Climate change skeptics obsess about the immense uncertainties that plague climate modeling. It’s not, however, all a matter of mysterious physics and chemistry. Human behavior — in this case our boundless capacity to ignore grave danger — poses the greatest challenge. No order of scientific progress nailing down the links that regulate Earth’s climate will enable certain projections of climate change over the next century because it is human behavior that controls the most powerful element: emissions of greenhouse gases such as CO2 and methane.

Today scientists with the international Global Carbon Project are releasing an updated accounting of CO2 emissions, and they far exceed the best guesses of human behavior by the Intergovernmental Panel on Climate Change (IPCC). “Emissions in 2007 were at the high end of’ those used for climate projections in the last [IPCC] report,” says Global Carbon Project participant Corinne Le Quéré, an environmental chemist at the University of East Anglia.

Emissions from burning fossil fuels and cement manufacturing — the largest sources of anthropogenic CO2 — continue to increase rapidly (see graph above); in 2007 they were now 38% higher than in 1990. In total, emissions drove up the atmospheric concentration of CO2 by 2.2 parts per million last year, compared with 1.8 ppm in 2006. At the end of 2007 CO2 was at 383 ppm — the highest concentration during the last 650,000 years and probably during the last 20 million years according to the Global Carbon Project.

At the same time the oceans, which in past acted as a buffer to absorb excess CO2, are saturating. Le Quéré, who coauthored a report last year in Science that the Antarctic Ocean had already saturated, calls it a dangerous combination: “If this trend continues and the natural sinks weaken, we are on track towards the highest projections of climate change.”

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September 26, 2008September 26, 2008 by pfairley