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Iron-Chromium Flow Battery Aims to Replace Gas Plants

Photo: EnerVault

The four round structures pictured above may look like grain silos but they're actually giant flow batteries. They're part of a demonstration plant going online this week, and proponents say it could represent the future of long-duration energy storage on the electric grid.

Startup EnerVault will unveil tomorrow what it says is the largest iron-chromium flow battery ever made. Installed in Turlock, Calif., the four-hour, 250-kilowatt battery will be charged by a solar array and power an irrigation system. The project was funded by about US $5 million from Department of Energy through the stimulus program and the California Energy Commission.

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Airbus’s E-Fan Electric Plane Takes Flight

The Airbus E-Fan took its first public test flight last month, making it the latest in a group of all-electric aircraft to take to the sky.

The flight was not just a media stunt. Airbus Group hopes to eventually develop a hybrid-electric regional plane that could seat 70 to 90 people, according to a report in Reuters. Developing such an aircraft, however, could take up to 20 years.

In the more near, term, Airbus sees a future for its E-Fan test plane. The composite, two-seater training aircraft is equipped with two lithium-ion polymer batteries (250 volts total) from KOKAM, a leading advanced battery maker, that are housed in the wings. The batteries provide 60 kilowatts of power to the plane's electric motors. The motors drive a variable pitch fan. The plane can fly for up to about 45 minutes, but Airbus says it can eventually get that flying time closer to an hour and 15 minutes.  

There are various electric aircraft prototypes across the world, but the difference is that Airbus is one of the world’s leaders in commercial aircraft manufacturing. (Check out 10 Electric Planes to Watch). While the A380 isn't going to go electric anytime soon, any breakthroughs that Airbus develops in electric-powered planes could reverberate through its business. 

Unlike some other electric aircraft, Airbus says that the E-Fan was built from the ground up to be electric rather than being based on existing fuel-powered airframes. For example, the landing gear is integrated into the fuselage for low drag, and the energy management and safety features were designed to be driven by electrical propulsion. There is a backup battery for emergency landing.

At the same time, the E-Fan needs to have flight parameters that are similar to existing training aircraft if it’s going to be used as a test plane. Ultimately, Airbus wants to construct a fleet of E-Fans and manufacture them close to the Bordeaux Airport in France. Production could start as early as 2017, according to Reuters.

Because the aircraft runs on electric motors, it emits no carbon dioxide during the flight and vibrates far less than a comparable fossil-fuel-powered plane. It is also quieter during take off and landing, which should be a benefit to communities surrounding test flight areas.

The investment in electric flight is spurred in part by the European Commission’s “Flightpath 2050” [PDF] which calls for a 75-percent reduction in aircraft CO2 emissions, a 90-percent drop in nitrous oxide emissions, and a 65-percent cut in noise levels compared with the respective numbers from the year 2000.

“It will not only lead to a further reduction in aircraft emissions and noise to support our environmental goals but will also lead to more economic and efficient aircraft technology in the long run,” Jean Botti, chief technical officer for Airbus Group, said in a statement.

The E-Fan will also make an appearance at the ILA Berlin and Farnborough airshows this year. Airbus has not released a projected cost for the electric plane.

UPower's Truck-Size Nuclear Power Plant

There are a number of efforts to build small modular nuclear reactors aimed at lowering the cost of nuclear power. But one company is designing a reactor that’s so small it would fit in a shipping container.

Boston-based UPower Technologies, founded by three nuclear engineers from MIT, is betting that its very small nuclear “battery” can be cost-competitive with power from diesel generators used in remote locations. It’s one of a handful of companies creating new reactor designs with the hopes of improving nuclear power’s safety and cost.

By building a very small reactor, the company thinks it can test full-scale prototypes cheaply and meet a market need for energy in remote places, such as mining operations, island nations, or military microgrids. It expects that its reactor would generate between one and two megawatts of electric power. By contrast, a full-size nuclear power plant typically produces about 1000 megawatts.  

In addition to being small, its reactor technology breaks with the dominant light water design. In today’s power plants, fuel rods held in metal assemblies are submerged in water. The heat from the core is converted into steam to turn a turbine and generate electricity. To avoid overheating in the core, water needs to be constantly circulated through it.

With UPower’s design, the nuclear reactor would be placed in a tall cylinder buried underground. Rather than remove heat from the core with water, company engineers have developed a system that’s similar in concept to steam radiators.

The reactor is equipped with a number of vertical stainless steel pipes filled with a mixture of liquid and gas. Those pipes are slotted into channels, or holes, in a metal block at the base of the reactor, explains CEO Jacob DeWitte. 

As the core produces heat, it causes the liquids at the bottom of the pipes to evaporate and rise to the top. That heat would then be converted into electricity using conventional generators. Removing the heat from these steel loops causes the gas to condense and drop to the bottom to begin the evaporation cycle again. "You don’t need pumps and it’s able to move the heat,” DeWitte says. “It’s a completely passive, self-contained phase change.”

In a light water reactor, water acts to both moderate the nuclear reaction and to transport heat from the core. With the UPower design, the steel pipes are enclosed and would only carry away heat. The nuclear fuel would also fit into channels in the metal block at the base of the reactor, DeWitte adds. He envisions using the same low-enriched uranium in conventional reactors but it could use other nuclear fuels.

The company went with this scaled-down approach for business reasons. The cost of testing a prototype of a new type of nuclear reactor costs millions of dollars, whereas DeWitte expects UPower could test its thermal management system at full size for thousands of dollars.

The reactor also seeks to improve on the safety of current plants. In the Fukushima disaster three years ago in Japan, a loss of back-up power to run water pumps caused the cores to overheat and melt down. With the UPower design, the heat would dissipate through a separate set of horizontal cooling loops that would transfer heat to the ground through natural convection, DeWitte says.

A number of countries, including China, Russia, and South Korea, are building new nuclear power plants. But in the United States, nuclear power is more expensive than building a new natural gas plant. UPower’s strategy is to target locations that pay high costs for energy because they need to import diesel fuel. Its reactors could supply both heat and electricity at lower costs, DeWitte says.

The company is one of a handful of nuclear startups that are hoping to bring advanced reactors to market. Among them are Bill Gates-backed TerraPower, Transatomic Power, and a few companies pursuing nuclear fusion, including General Fusion, Helion Energy, and TriAlpha Energy. There are also a number of efforts to build small modular reactors, which are light water reactors designed to be simpler to build and install than full-size plants.

By working through a startup, rather than a national lab, entrepreneurs hope to move quickly and commercialize new nuclear technology But the process of obtaining a license to operate advanced reactors will likely take many years, says Jessica Lovering, a nuclear policy analyst at think tank the Breakthrough Institute. “All the regulations and applications are very focused on the light water designs,” she says. “The whole fuel cycle is optimized for it.”

DeWitte is hopeful that the company can test its basic design by the end of next year and start the licensing process. There’s a demand for alternatives to diesel generators in remote locations and strong commercial interest could help speed up the approval process, he says. 

Vattenfall Ditches Carbon Capture and Storage Research

Vattenfall, one of Europe’s largest energy producers, announced this week that it will discontinue its research and development activities in carbon capture and storage (CCS) for coal-fired power plants.

The move comes as Vattenfall looks to shore up costs as profits fall considerably for European power producers. Vattenfall said in a statement that research will continue in smart grid, wind, hydro, coal, and nuclear.

"Tough market conditions are expected to continue for another few years, and we are restructuring our research and development operations as it is becoming increasingly important to have the right knowledge at the right time to meet the ever-changing needs of business," Karl Bergman, head of R&D Nordic for Vattenfall, said in a statement.

Europe’s power producers are already losing money on many coal and natural gas power plants due to depressed wholesale electricity prices from the recession, coupled with increased renewable capacity due to decarbonization policies. A study earlier this year from Oxford University [PDF] found that coal prices have fallen by about one-third in Europe since 2011.

Despite years of research, CCS continues to be an expensive option to cut greenhouse gas emissions from coal-fired power plants. Even in the European Union, which has decarbonization policies, it has yet to become a commercial-scale, affordable option to keep older coal plants operating while producing fewer emissions.

Vattenfall does not have money to bet on technologies that might not pay off in the near term. The Oxford study found that the Swedish power giant wrote down €3.46 billion (US $4.78 billion) in 2013 related to losses from coal and natural gas plants in the Netherlands and Germany.

The Vattenfall announcement is another blow to CCS, but there are some other bright spots on the globe for the technology. A 110-megawatt coal-fired power plant refitted with carbon capture in Saskatchewan is expected to come online within weeks, according to MIT Technology Review. The utility that owns the plant, SaskPower, is using some CCS research from Vattenfall. Vattenfall said it would continue knowledge exchange with other entities even though it will not conduct further research.

Another project, in Mississippi, will install carbon capture on a coal plant and is expected to start up later in 2014. Like the Canadian project, it can reduce costs because it uses cheap lignite coal and it is can sell the carbon dioxide to nearby oilfield operators. In January, the U.S. Energy Department pledged $US 1 billion towards a carbon capture and storage project in Illinois.

But in most regions, the outlook for CCS is unsure at best. The Norwegian government announced last fall that it would not escalate a large CCS pilot project to commercial-scale operation.

CCS is not the only research area to get axed by Vattenfall. The company said it will also close down “a number of” projects in offshore wind and gas power. For wind and hydro, the focus going forward will be on lessening environmental impacts of new projects. Vattenfall’s nuclear research will continue into how to safely dispose of spent nuclear fuel and it will also continue to look at ways to use coal assets as a regulator for intermittent renewables.

"We now need to prioritize our R&D investments and choose whatever is most needed,” said Bergman. “We are opting for efficient research projects that can contribute further to our business operations, now and in the future."

Monitoring Nuclear Fuel With Sound

Nuclear reactors are packed with a host of sensing and control systems. But at their innermost core, where nuclear fuel burns inside metal rods, conditions are so extreme that placing any kind of sensor has been a huge challenge. As a result, reactor operators haven't been able to get a complete picture of how their nuclear cores are performing.

Now researchers have developed sensors that convert the heat differences inside the reactors into whistle-like sounds that reveal the condition of the fuel. These thermoacoustic sensors could provide operators with valuable data like temperature, gas composition, and pressure inside the fuel rods, as well as fuel burn-up rate and swelling of the rods.

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DOE Spends $141 Million to Speed Offshore Wind Project Development

Though the actual waters off of the United States' windy shores remains free of turbines (with one minor exception), the theoretical waters are getting crowded with turbines. Along with frontrunners Cape Wind and Deepwater Wind near Massachusetts and Rhode Island, a few other projects are starting to get the sort of backing that will help them join the party. Yesterday, the Department of Energy announced funding of up to $47 million each for three projects off of New Jersey, Virginia, and Oregon.

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U.S. Climate Report Predicts Growing Problems for Energy Sector

More frequent and intense weather events—from hurricanes to wildfires to sweltering summers—can be attributed to climate change and are affecting energy production and power delivery in the United States, according to a new government report.

The latest National Climate Assessment, prepared by the U.S. National Climate Assessment and Development Advisory Committee (NCADAC) and released yesterday, says that climate-related effects are not only already being felt but will likely get worse.

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Two Labs Get the Lead Out of Promising Perovskite Solar Cells

Photovoltaic cells made from perovskite materials have rapidly become one of the hottest areas in energy research over the past few years. But most of these materials have included the toxic metal lead, raising concerns about their environmental impact.

Now, two teams have independently developed perovskite cells that swap lead for tin, which could help to convince investors and regulators that the cells have a commercial future.

Perovskite materials are named after the common crystal structure they share with a naturally occurring mineral. Cells using the material made a modest debut in 2009, reaching energy conversion efficiencies of 3.8 percent.

But they were soon leaping ahead, rising to 10 percent efficiency in 2012, and 15 percent by 2013. The same year, Henry Snaith at the University of Oxford, UK, unveiled a perovskite cell that reached 15 percent efficiency, but with a much simpler design. His device relied on a thin film of methyl­ammonium lead iodide chloride to do double duty as both light absorber and charge carrier. Since then, photovoltaic cell efficiencies have ticked up further, to 17.9 percent—an advance achieved by Sang Il Seok at the Korean Research Institute of Chemical Technology in Daejeon.

This efficiency already rivals that of bulkier silicon cells, and is gaining fast on thin-film photovoltaic cells that use materials such as copper indium gallium selenide (CIGS). The unprecedented progress is made all the sweeter by the fact that these perovskites are extremely stable, use cheap and abundant materials, and are simple to incorporate into cells.

But using lead-based materials was obviously not ideal. There were only small amounts of lead in each cell, but enough to have a significant environmental impact if they were deployed widely around the world. Researchers worried that this might limit their use. “It’s a problem when it comes to convincing investors,” says Mercouri Kanatzidis, a chemist at Northwestern University, Evanston, Illinois.

Snaith has now reported in Energy and Environmental Science that a cell made from methyl­ammonium tin iodide, which is lead-free, is about 6 percent efficient. Just days later, Kanatzidis independently reported very similar results in Nature Photonics using methyl­ammonium tin iodide bromide.

One major drawback is that tin perovskites are unstable, and must be handled under an inert atmosphere. But Kanatzidis says that the necessary processing methods are already well-established in industry, and that the cells are fairly stable once sealed in an air-tight housing. He is also confident that tin perovskites can be pushed far above 6 percent efficiency. “There’s no showstopper,” he says.

Tin perovskites might offer an insurance policy if lead perovskites do turn out to be an environmental problem. But looking for alternative metals is also smart science, because they might actually improve the cells’ performance. The tin-based cells, for example, actually produce a higher voltage than the original lead perovskite cells. “It may well be that tin ends up being higher efficiency,” says Snaith.

The similarities between the results from the two labs highlights the frenzied pace of the field. “The competition is amazing,” says Snaith. “You can’t assume you’re doing anything unique.”

Snaith has cofounded a start up, Oxford Photovoltaics, to commercialize his perovskite cells, and Kanatzidis is talking to solar PV manufacturers about his tin tech. But both agree that the biggest hurdle for commercial deployment of the cells is their long-term stability. “The biggest question is whether we can make these things stable for 25 years,” says Snaith.

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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