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NASA Uses Transmission Lines For Geomagnetic Antenna Study

Not all threats to the electric grid originate here on Earth. To better understand large solar events, which can be dangerous to the transmission grid, a researcher at NASA’s Goddard Space Flight Center is using high-voltage transmission lines to map large-scale geomagnetically-induced currents (GICs).

GICs occur when the sun ejects huge bubbles of charged particles that can carry up to 10 billion tons of matter. When the bubbles strike the Earth’s atmosphere, the geomagnetic field that surrounds our planet fluctuates.

These fluctuations in the electrical current can then flow through any large conductive structure such as power lines, oil and gas pipelines, undersea cables, and railways, according to NASA. When excess current flows through the electric transmission system, it can overload transformers and collapse the system, leading to large-scale outages. From 1960 to 2000, the high voltage grid in the United States has grown nearly tenfold, according Oak Ridge National Laboratory [PDF], making it increasingly susceptible to GICs.

The concern that a large GIC could plunge part of the United States into a blackout is high on the list of issues faced by the Federal Energy Regulatory Commission (FERC), and is as much of a focus as physical or cyber security threats.

Last year, FERC ordered the North American Reliability Corporation to propose reliability standards for the grid that address the impact of geomagnetic disturbances; owners of the bulk-power grid will have to conduct assessments of the potential impact of GICs on their systems moving forward.

To better understand the effects of GICs, Antti Pulkkinen, a heliophysicst at Goddard, is installing three substations beneath high-voltage transmission lines to measure GICs.

“This is the first time we have used the U.S. high-voltage power transmission system as a science tool to map large-scale GICs,” Pulkkinen said in the NASA publication Cutting Edge [PDF]. “This application will allow unprecedented, game-changing data gathering over a wide range of spatial and temporal scales.”

Two of the three substations being built by Goddard engineers will be buried 1.2 meters below ground at a spot where Dominion Virginia Power’s high-voltage lines pass overhead. The lines will act as antennae for the electrical current. The substations will contain commercially available magnetometers that can make precise measurements of GICs. (The third substation will be located about three kilometers away to provide reference measurements.)

Pulkkinen’s team is using technology also developed at Goddard to command and control the magnetometers from an iPad. The application, which tags and geolocates data, will send it to a server once every second.

The pilot project is expected to last one to two years, but Pulkkinen hopes to eventually deploy hundreds of substations with long-term funding from multiple government agencies. The current project is funded by NASA’s Center Innovation Fund and Goddard International Research and Development program.

GE's Distributed Power Station Delivery Goes From Months to Weeks

When utilities needed new sources of power in the past, they planned for large, capital-intensive centralized generation that could take years to build and decades to pay off.

Big power plants are still being built, but many utilities are increasingly looking for smaller, more flexible solutions. In Libya, the General Electricity Company of Libya (GECOL), recently installed mobile backup power plants from General Electric (GE) in a matter of weeks, instead of the six-to-nine months usually required.

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U.S. Energy Department Offering $4 Billion for Renewable Energy Loans

Biofuels made from leftover corn may not be any better than conventional gasoline in terms of greenhouse gas emissions, according to a new study from Nature Climate Change that was paid for by the U.S. government.

In terms of life cycle analysis, fuels made from corn residue release 7 percent more greenhouse gases in a 10-year timeline compared to gasoline, even though they may be better than gas in the long run, according to a report in the Associated Press. The federal government has spent more than US $1 billion supporting cellulosic biofuel research.

Although the fuel stock may change, biofuels continue to be a big focus for the government. Biofuel-based drop-in replacements for gasoline are one of five technology areas that were identified as part of the U.S. Department of Energy’s (DOE) latest renewable energy and energy efficiency solicitation.

The DOE will offer up to $4 billion in loan guarantees to help commercialize technologies that may not be able to obtain full commercial financing, the agency said last week. The program falls under a different section of the law than the part than the one that funded Solyndra.That section,1705, has now expired but had a more than 90 percent success rate across the portfolio despite some significant failures. 

“Through our existing renewable energy loan guarantees, the Department’s Loan Programs Office helped launch the U.S. utility-scale solar industry and other clean energy technologies that are now contributing to our clean energy portfolio,” DOE Secretary Ernest Moniz said in a statement. “We want to replicate that success by focusing on technologies that are on the edge of commercial-scale deployment today.”

The DOE will take applications for any project that meets the eligibility requirements, but it is particularly interested in: 

  • Advanced grid integration and storage
  • Drop-in biofuels
  • Waste-to-energy
  • Enhancement of existing facilities
  • Efficiency improvements.

For biofuels, the DOE noted “qualifying projects may include, but are not limited to, the following: new bio-refineries that produce gasoline, diesel fuel, and/or jet fuel; bio-crude refining processes; and modifications to existing ethanol facilities to gasoline, diesel fuel, and/or jet fuel.”

The U.S. Department of Defense, in particular, is eager for drop-in biofuels to meet its goals. The Navy, for example, has a goal of 50 percent of its liquid fuels will come from alternative sources by 2020.

It is unclear if the findings from the Nature Climate Change study would be considered by the DOE for any applications that are related to corn residue biofuels. According to the AP, other research, including a study by the DOE’s Argonne National Laboratory, has found that corn-based biofuels were still better than gasoline in terms of greenhouse gas emissions.

There will be plenty of other technologies, both other feedstock for biofuels, and other areas of clean tech, that will be vying for the loans. In the first quarter of 2014, more than 90 percent of new power generation was renewable energy, according to the US Federal Energy Regulatory Commission [pdf].

In the area of advanced grid integration and storage projects would help mitigate grid issues caused by intermittent renewable energy. Along the same lines, the DOE's funding for “enhancement of existing facilities” will focus on incorporating renewables into existing generation facilities.

Waste-to-energy applications should focus on projects that turn landfill methane or segregated waste streams, such as forestry waste or crop waste, into energy. Energy efficiency is also a key area, and could fund efficiency in residential, commercia,l or industrial processes or ways that efficiency and demand response could help dispatch underutilized renewable energy.

The DOE is taking public comments until 16 May and the final solicitation will be issued in June.

White Light, Stored Heat

Researchers have developed a new material for solar thermal energy applications, a collector that can serve as its own heat battery. As a result, the technology could help smooth out the production of electricity from solar power over a day and night cycle, or during cloudy weather.

The essential idea, says MIT postdoctoral research associate Timothy Kucharski, involves a molecule containing a kind of spring-wound hinge. Exposing the molecule to a burst of sunlight latches the solar energy in place, like arming a mousetrap. The molecule can then be left idle until its energy is needed, at which point a simple chemical catalytic reaction springs the molecular hinge and releases the stored solar energy as heat.

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Supercapacitor-Enhanced Hybrid Storage to Earn Cash for Subways

A moving train represents a significant amount of energy, which is often lost as carriages slow to stop at a station. Trains in the Philadelphia subway are not only capturing that energy in banks of batteries but also selling it to the local grid operator. This fall, it’ll be capturing even more energy—maybe earning more money from grid operators—because it plans to upgrade the system with a hybrid of both lithium ion batteries and supercapacitors.

The Southeastern Pennsylvania Transit Authority (SEPTA) stores energy produced by braking railway cars, much the way a hybrid car juices its battery when slowing. The spinning wheels turn a motor-generator to charge a bank of batteries via a third rail system. The battery is located at the Lettery substation, which powers a portion of the Market-Frankford Line in Philadelphia, and the autumn upgrade will be installed on the same line about 5 kilometers away.

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Time to Rightsize the Grid?

Last week a team of systems scientists known for counter-intuitive insights on power grids delivered a fresh one that questions one of the tenets of grid design: bigger grids, they argue, may not make for better grids. Iowa State University electrical engineering professor Ian Dobson and physicists David Newman and Ben Carreras make the case for optimal sizing of power grids in last week's issue of the nonlinear sciences journal Chaos. 

In a nutshell, the systems scientists use grid modeling to show that grid benefits such as frequency stabilization and power trading can be outweighed by the debilitating impacts of big blackouts. As grids grow larger, they become enablers for ever larger cascading blackouts. The Northeast Blackout of 2003 was a classic case. From a tripped line in northern Ohio, the outage cascaded in all directions to unplug more than 50 million people from western Michigan and Toronto to New York City.

This week's findings are more conceptual, however, than some news outlets would have us believe. NBC News, in an online article entitled Researchers Suggest It's Time to Downsize Power Grid, misjudged the Chaos report as a call to break up the dual grids that interconnect most of eastern and western North America. "It’s not possible to really make that statement," says Carreras, who runs Oak Ridge, TN-based consulting firm BACV Solutions and is a visiting professor at Madrid's Universidad Carlos III.

B.A. Carreras/BACV Solutions

NBC misinterpreted Carreras et al's simulations showing that grids with just 700-1000 nodes (over 15 times smaller than North America's big grids) maximize interconnection benefits while minimizing blackout costs (see above chart). The researchers say this could indicate that some real grids are too large, but there are two big reasons to be cautious about drawing conclusions. 

Carreras stresses that the model nodes are not necessarily representative of those on a real grid. Many of the group's simulations, for example, use scale models of the Western grid in which each node in the model represents, on average, 10 nodes on the real grid. 

Newman, a physics professor at the University of Alaska in Fairbanks, notes that the specific models used in this Chaos study were idealized, homogeneous systems. As such, he says, they bear little resemblance to the heterogeneity of real grids with their diversity of voltage levels, branching patterns and other features. "700-1000 nodes was the optimal size for the artificial network we had constructed," says Newman.

Media hype is a problem that has dogged this team of system scientists since they gained notoriety over a decade ago by identifying cascading failures as an innate feature of power grids. Their simulations, which a Spectrum cover story profiled ten years ago, show that economic pressure to maximize return on investment loads power grids to levels that leave them at heightened risk of costly blackouts.

The researchers delivered a complex systems view of blackouts that they hoped would spur novel thinking about the costs and benefits in grid design, and novel approaches to blackout prevention. But their message was often misinterpreted as an attack on the quality of grid engineering, or an argument that trying to prevent blackouts was futile. 

Carreras et al argue that this week's report has important conceptual value, if one gets beyond the hype. For one thing, blackout risks should be factored into the cost-benefit calculation when grid planners consider expanded interconnection. This could be applicable in developing countries as well as in Europe, which recently expanded its grid to include Turkey's and is considering extensions to North Africa and Russia.  

It's also possible that grid design could be engineered to enable extended interconnection without expanding cascading blackout risk. Newman points to the possibility that weak links could be deliberately placed within grids to confine cascading blackouts to their region of origin. The team's next step, says Newman, is to study just that possibility by simulating and optimizing heterogeneous networks. 

A correction to this post was made on 23 April 2014: Ian Dobson is at Iowa State University, not the University of Iowa as originally reported.

Tequila Sunrise: Big Benefit from Co-Locating Agave Crops and Solar Power

Solar power in the desert has problems: big land use requirements, and the need for scarce water to clean the panels and suppress dust. In an unrelated story, biofuels production has problems: life cycle greenhouse gas emission issues, and land use questions again. How about solving both sets of problems at once? Stanford researchers have modeled the co-location of solar panels with agave plants used to make ethanol, and found it to be a winning combination.

The idea of "agrivoltaics", or combined solar power and agricultural production, has been floating around for a while now. It's an idea that springs at least partially from the modern distaste for "monoculture", or the growing of a single crop over huge swaths of land. The reasoning: Instead of "growing" only solar power on a plot of land, why not use the space between and underneath the photovoltaic panels to also grow crops? There are some projects in France that have tried this, and a post-Fukushima Renewable Energy Village in Japan also features crops underneath PV. There are also experiments at the University of Massachusetts, and some small-scale "solar farm" installations in Wisconsin.

It seemed unlikely, however, that the idea of studding the land around the solar plants that have started cropping up across the arid deserts of the American southwest would take root. But the Stanford folks, led by post-doctoral researcher Sujith Ravi, realized that the water required for a solar plant could actually make the desert more hospitable to agriculture as well. To test the idea, they chose agave plants, biofuel sources that are already quite hardy and require little water to survive.

They found that by combining a PV plant with agave production, a given area could yield more energy for the same amount of water than either PV or agave alone. The study, published in the journal Environmental Science & Technology, showed a "high-yield" scenario where only 0.42 liters of water would be needed to produce one mega-joule of energy.

"It could be a win-win situation," Ravi said in a press release. "Water is already limited in many areas and could be a major constraint in the future. This approach could allow us to produce energy and agriculture with the same water." This marriage of agave and solar panels is especially compelling for two reasons. First, because agave plants require roughly the same amount of water needed to keep solar panels clean and to suppress dust, it's possible to use the water dripping off a newly cleaned solar panel to nourish the plant. And a 2011 study found that the plants, also used to make tequila, perform just as well or better than corn, sugarcane, and switchgrass in terms of lifecycle greenhouse gas emissions and other parameters.

Aside from planting crops beneath existing solar panels, there are other ways to think about combining PV with plants. In a report on the topic, the National Renewable Energy Laboratory encouraged farmers to consider locating solar panels in the unused corners of their center-pivot farm plots. In Colorado alone, those currently underused spots could generate enough power to meet all of the state's electricity needs. Clearly, farming and solar power should become much better friends in the future.

Scientists Discover Efficient Way to Turn Carbon Monoxide Into Ethanol

Biofuels, once hailed as a planetary savior and alternative to oil and gas, have not quite fulfilled that destiny. Traditional, mass-produced biofuels from crops such as corn carry a litany of problems, including land use issues and questions of life cycle emissions. If we could generate usable fuels from more benign sources, it could go a long way toward solving a host of energy and environmental problems. A team at Stanford University reports today in Nature that they have a novel way to produce ethanol from carbon monoxide (CO) gas using a metal catalyst made of copper nanocrystals.

"We have discovered the first metal catalyst that can produce appreciable amounts of ethanol from carbon monoxide at room temperature and pressure—a notoriously difficult electrochemical reaction," said senior study author and Stanford chemistry professor Matthew Kanan in a press release.

Copper is the only material known to electroreduce CO down to generate fuels, but it does so at extremely low efficiencies. Kanan's group improved this with a nanocrystalline form of copper produced from copper oxide; this new material improves the efficiency of the reactions dramatically.

The researchers built a fuel cell, including a cathode made of the new copper nanocrystals, and suspended it in CO-saturated water; a small voltage applied across the fuel cell generates the resulting ethanol products. The Faraday efficiency using the oxide-derived material was 57 percent, meaning more than half of the current used went toward producing ethanol and acetate. Standard copper particles, meanwhile, produced hydrogen almost exclusively (Faraday efficiency of 96 percent) and very little ethanol.

In an e-mail, Kanan said a few years is probably enough to turn this basic work into prototype devices, outside of the lab, that can produce meaningful amounts of fuel. "Some of the technical issues include reformulating the catalyst such that it can be dispersed on high-surface area electrodes, and engineering an electrochemical cell that delivers CO to the catalyst at a high rate," he said. The long-term stability of the oxide-derived copper catalyst is still in question as well. Kanan declined to offer guesses on eventual costs of the device, given its still lab-bound status; copper, however, is not particularly expensive, as catalysts go.

If the details of this were actually to work out and at an acceptable cost, it could be enormous. Though there have been changes proposed recently in the biofuels mandate in the United States, we're still producing billions of gallons of the stuff each year, virtually all of it from corn. The big idea with the new catalyst would be to power the fuel cell using renewable energy rather than from fossil fuels; ideally, one would just grab carbon dioxide out of the atmosphere and turn it into CO.

"There is good technology for converting CO2 to CO using an electrical energy input, although it requires high temperatures," Kanan told me. "There has been much work by many groups including ours to develop a low temperature electrochemical process for converting CO2 to CO, and a number of good catalysts have been found recently. I don't think the CO2-to-CO would be a limiting factor."

Energy Efficiency Grows as Clean Energy Investment Falters

Global investment in clean energy fell 11 percent in 2013. Despite the downward shift, there are still some bright spots that highlight the future of the world’s clean tech industries.

Investment in solar, wind, biofuels, biomass, energy efficiency and energy storage was US $254 billion in 2013, according to a new report [PDF] from Pew Charitable Trusts.

While the stars of the market, wind and solar, have slipped, the unused kilowatt—aka energy efficiency—saw a 15 percent growth in the past year. Investment might be down overall, but 2013 was still a record setting year that also saw energy storage take a foothold in the market.

Solar and wind, with more than $170 billion in investment combined, still make up the lion’s share of the clean tech industry. But energy efficiency, which includes smart meters and energy storage, was the only sector that saw increased investment, with a total of nearly $4 billion in 2013. Most of the efficiency investment was in the United States, where there is an increased focus on saving energy at the state and federal level.

“While there was an overall decline in investment, there are signs that the sector is reaping the rewards of becoming a more mature industry,” Phyllis Cuttino, director of Pew's clean energy program, said in a statement. “Prices for technologies continue to drop, making them increasingly competitive with conventional power sources. Key clean energy stock indexes rose significantly in 2013, with public market financing up by 176 percent.”

Although the United States led in energy efficiency, Asia is leading the clean tech charge overall with 10 percent growth. China dominated with more than $54 billion in investments in 2013, including a near four-fold increase in solar growth.

“With extensive manufacturing capacity in the solar and wind sectors, growing domestic markets, and unequaled national targets for renewable energy, China is poised to be a leader in the world’s clean energy marketplace for many years to come,” the report authors wrote. Even so, China’s investment was down 6 percent from 2012.

China’s slight decline was offset by the growth in the Japanese market, which is driven by feed-in tariffs for wind and solar. Those incentives were presented as a way to advance renewables as an alternative to nuclear power that went offline in the wake of the 2011 Fukushima nuclear disaster. Japanese clean tech investment was up 80 percent in 2013 to nearly $30 billion, putting it third behind China and the United States.

Overall, the European clean tech market has dropped considerably, driven by tighter investment in Germany and Italy in particular. The U.K. is one bright spot for clean energy in Europe, with 13 percent growth in 2012. Most of the growth came in the wind sector, but the UK is also second in the G-20 in terms of “other renewables” because of its investment in biomass.

In the Americas, Canada jumped ahead with a nearly 50 percent growth in investment, also mostly driven by wind. Ontario, in particular, has a goal of completely shutting down its coal-fired electricity generation. But solar was up too, attracting $2.5 billion of the country’s $6.5 billion investment.

Canada, the U.K., and Japan were the only G-20 countries that saw growth, but non G-20 markets grew by 15 percent overall. “Markets for clean energy technologies in fast-growing developing countries are prospering, because these economies view distributed generation as an opportunity to avoid investments in costly transmission systems,” said Pew's Cuttino.

Distributed solar is expected to keep growing in the United States and Japan. Mexico and Turkey each have legislation that could jump start the clean tech industries, according to the report. South Korea is investing in efficiency to manage peak demand. China will continue to lead, however, with goals of 18 gigawatts of wind and 14 gigawatts of solar in 2014. 

“In view of industry maturation,” the Pew authors wrote, “Bloomberg New Energy Finance projects a 2014 rebound in worldwide investment and installation of renewable energy.”

 

Image: Pew Charitable Trusts

White House Taps ARPA-E to Boost Methane Detection

In this month's issue of IEEE Spectrum we spotlight the methane emissions overlooked by the U.S. EPA's greenhouse gas inventory, and the satellite-based detector launching next year to map this "missing methane." Last week the White House acknowledged EPA's missing methane problem, and laid out a strategy to combat it. While promising to improve EPA's inventory, including more use of top-down methane measurement, the White House also promised federal investment in ground-based methane sensing to plug leaky natural gas systems thought to be the source of much of the missing methane.

Action can't come soon enough according to the Intergovernmental Panel on Climate Change (IPCC), which on Monday unveiled its latest report on Climate Change Impacts, Adaptation, and Vulnerability. The IPCC said "widespread and consequential" impacts are already visible and world leaders have only a few years to change course to avoid catastrophic warning. Methane is a major contributor according to the scientific body's update on the physical basis for climate change, released last fall, which deemed methane to be up to 44 percent more potent as a warming agent than previously recognized.

The White House says that the U.S. Department of Energy's ARPA-E high-risk energy R&D fund will contribute by seeking to improve natural gas sensors, which are presently sensitive or cheap but not both. ARPA-E is preparing a new funding program that the White House says will "deliver an order-of-magnitude reduction on the cost of methane sensing, thus facilitating much wider deployment throughout all segments of natural gas systems."  

One contestant for funding could be robotic systems such as the Swedish-developed Gasbot profiled by Spectrum last year. Gasbot, a project from Sweden's Örebro University, uses a mobile robot from Kitchener, Ont.-based Clearpath Robotics equipped with a laser-based remote gas sensor to map methane concentrations across a potential leak site. Orebro doctoral student Victor Hernandez says the Gasbot team has implemented improvements since Spectrum's coverage, including the addition of an anemometer to help determine where detected emissions are coming from.

Using a robot might reduce labor costs and accelerate the process of mapping a site, such as a natural gas plant or a landfill, and Hernandez says a market survey conducted last year has confirmed commercial interest in Gasbot. But Örebro's package doesn't come cheap in its present incarnation. The gas sensor alone costs about 10 000 (US $13 760), he says, and the Clearpath A-200 robot is another $12 000 or so.

Another contestant could be the laser science research group at Rice University, in Houston, which has recently demonstrated two novel strategies for building compact, sensitive and potentially low-cost methane detectors. The best developed relies on recently miniaturized mid-infrared quantum cascade lasers and cheap piezo-electric devices to detect the laser-excited heating of traces of methane gas—traces as thin as 13 parts per billion (ppb) according to group leader Frank Tittel, a professor of electrical engineering. His newer system uses advanced optics to more than double the methane sensitivity.

Tittel's group has already proven its devices at a Houston landfill through a NASA program designed to calibrate space-based measurements of methane and other pollutants. He projects that the piezo-electrically tuned sensor could be scaled down and mass produced to deliver a $1000 system the size of a smart phone. The key, says Tittel, is mass production of the lasers, which currently cost $12 000.

Tittel says his group has teamed up with Newton, N.J.-based Thorlabs, which makes the required quantum cascade lasers as well as the electronics, mechanical stabilizers, and optics to build an integrated product.

Thorlabs appears to be keen. The company presented at an ARPA-E methane technology workshop last year, and declared its intention to "grow the [mid-infrared laser] market by reducing component costs." 

Message to missing methane: You may soon have nowhere to hide.

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