E&E Exchange

"The power of the sun… in the palm of my hand."

So said Dr. Otto Octavius, the infamous scientist turned supervillain, in the movie Spiderman 2.

What he was referring to in that quote was the fusion reactor he had created, a device that generated a self-sustaining energy source like that of the sun. It was this device that quickly turned out of control, generating a strong magnetic force that nearly leveled the building and resulted in the death of his wife. From then on, Dr. Octavius was Doctor Octopus - Doc Ock.

(<--It will stabilize! Credit: Chanmainor.com)

The reality of fusion is not too far off from the Hollywood version. Fusion is the process of combining two atomic nuclei together to create one new (heavier) atom. Its simplest form involves two hydrogen atoms (one proton each) combining to form one helium atom (two protons). This process of fusion produces massive amounts of energy, as exemplified most prominently by the sun that heats our planet. The hydrogen bomb, which uses a nuclear explosion to generate the high temperatures needed for the reaction, is the most prominent working example of fusion we have.

(Fusion reaction. Credit: CCFE-->)

Harnessing that energy in a useful (i.e. none destructive) manner though is a real challenge for the physicists and engineers working to build fusion reactors. To achieve high enough fusion reaction rates to make fusion viable as an energy source, the fuel (two types of hydrogen - deuterium and tritium) must be heated to form a plasma at over 100 million degrees Celsius. Wow that's hot! When these temperatures are achieved, the fuel begins fusing to create helium atoms. The heat from fusion then provides the energy to sustain the plasma's temperature, and the excess heat can be harnessed to heat steam to drive a turbine and generate electricity.

The most promising fusion technology involves a machine called a tokamak. The tokamak utilizes a ringed magnetic confinement system; a circular bottle surrounded by strong magnetic fields. This confinement isolates the plasma from the outside environment in order to maintain stable temperatures and prevent contamination with impurities. Check this link for a picture of ITER: the world's largest tokamak.

The latest developments in fusion technology involve the Joint European Torus (JET), Europe's premier magnetic confinement fusion facility based at Culham, UK. It has completed eleven months of tests to simulate the environment inside the ITER fusion facility being built in the South of France, and to prototype key components. JET is basically a mini-version of ITER, using the same materials for its wall - beryllium and tungsten. These materials have been carefully selected in order to minimize plasma contamination and prevent fusion fuels from becoming trapped in the wall.

(The interior of JET, showing its new wall of beryllium and tungsten. Credit: EFDA)

Initial tests with beryllium and tungsten have proven that they work much better than carbon-based wall materials. Specifically, experimenters found the amount of fuel retained in the wall was at least ten times less with the new design. These results may convince the ITER project to skip its initial operation with carbon, which would save the project both time and money.

Experiments at JET will restart in 2013, with the goal of demonstrating full deuterium-tritium based plasma tests by 2015. This is an exciting prospect for the development of the ITER, which plans to create its own first plasma by 2020. The possibility of commercial fusion energy is definitely a bright light amidst the clouded future of sustainability, and I will be keeping my eye on the progress.

Paving the Way for Commercial Fusion Power Plants - Science Daily

How Fusion Works - CCFE

The Science - ITER

Since global warming became a hot topic, methane (CH₄) gas emissions have been a point of concern on the backburners of carbon dioxide. Considering that methane's global warming potential is 72 times that of carbon dioxide over 20 years and 25 times over 100 years, it shouldn't be ignored. Two primary contributors to methane gas production in the atmosphere are cows and automobiles, raising the infamous question 'does a cow pollute more than a car?' For those concerned about that debate, here is some insightful reading on cow backpacks.

One of the ways methane emissions are curbed in cars (and gas turbines, another big methane producer) is through the use of catalysts to encourage combustion. In cars, these are found in catalytic converters, which facilitate the oxidation (burning) of methane along with many other nasties produced by the engine. The combustion reaction for methane is:

CH₄ + 2O₂ --> CO₂ + 2H₂O

(<-- The catalytic converter - an asset to the environment and a target for car thieves... Credit: Wired)

In traditional catalytic converters, though, it's hard to find catalysts that fit the bill for encouraging this reaction. Catalysts are designed to assist chemical reactions by making them happen more efficiently and effectively. Currently available catalysts for methane combustion are not 100% efficient however, allowing a lot of unburned fumes to leave with the exhaust. The difficulty is, methane combustion catalysts need to be both active enough to do their job effectively, and stable enough to withstand the harsh conditions surrounding the process - particularly in regards to temperature.

A new catalyst for methane, developed by a collaboration of catalysis and energy specialists, could potentially fix these problems. It achieves complete methane combustion at 400°C, the approximate exhaust temperature for normal cars. This is crucial, considering most other catalysts can only achieve 100% efficiency at temperatures above 600°C. The catalyst also resists breakdown from hotter temperatures up to 850°C, which can occur when more load is put on the engine (climbing hills and driving fast).

(Representation of the catalyst's core-shell structure on an aluminum oxide surface. Credit: University of Pennsylvania -->)

The new catalyst has yet to be tested under real-world conditions, which could be drastically different than the performance recorded in lab. Vehicle exhaust in particular, which contains catalyst-disabling components (like sulfurous compounds, oil-additives, and steam), could deter the effectiveness of the substance. However, this development is a big first step towards a real solution, and opens the doors for creating similar structures which may perform better.

References

Catalyst Could Zap Methane Emissions - CR4

Cheaper and Cleaner Catalyst for Burning Methane - Science Daily

In the last decade, particularly the last four years, we have seen a tremendous push for electric vehicles (EVs). The end goal of many advocates of EVs is to see them replace conventional gasoline powered cars to reduce exhaust pollution and limit the use of fossil fuels.

And while this goal in some ways has more to do with the source of grid power, there are already enough difficulties with the cars themselves. In comparison to conventional cars, EVs are much less practical and more expensive. But newly developed fast chargers are looking to change this.

One of the biggest challenges for EVs is battery charging. Most designs have an average range of less than 100 or so miles per charge. Tesla's Model S has one of the highest ranges, at ~300 miles per charge. But even a 300 mile range presents a problem for long distance travelers looking to go hundreds of miles in one trip, since charging can take hours or days. Specifically, it takes the Chevy Volt four hours, the Nissan Leaf seven hours, and the Tesla Model S nearly twelve hours (whoa!) to charge on a regular outlet modified for 240V (the voltage of most charging stations). In this way, the 450 mile road trip I took many times from my hometown to my college would take two days rather than 7 ½ hours. That's just not happening.

(A Tesla Roadster at a traditional charging station. Credit: AP Photo | Rick Bowmer)

A new DC fast charging station developed by Tesla Motors presents a solution to this problem. These stations deliver DC power directly to the battery, bypassing the car's on-board charger by converting AC grid to DC outside the car. A communications link in the charging cord allows the car's battery management system to control the rate of charge to avoid damage to the battery. In this way, the fast chargers are designed to limit charging to 80% of full capacity to avoid overcharging or battery damage.

While standard 240V stations provide only 3.3 kW power, fast chargers can deliver from 20 kW to 100 kW depending on the design. This reduces charging times by hours, allowing most EVs to charge to 80% in just around half an hour or so.

As convenient as the fast-chargers seem, they have many drawbacks. First and foremost, the capital costs are reportedly very high, with individual charging units costing tens of thousands of dollars. In addition, fast-chargers may not be as frequently used, considering that most EVs are purchased for commuting and are charged overnight or during the day. Compounded together, these factors make it difficult to justify an investment in these stations.

Other foreseeable barriers include the hefty demand that these stations put on the grid. Utilities often charge a demand fee each month for stations that expect to draw a lot of power. This fee is paid regardless of how much use the station gets.

Finally, even if battery costs come down and the grid expands to allow for more electric vehicles, I can't see Americans choosing electric over gasoline. Often people are willing to pay more for convenience, but right now conventional cars are both less expensive and better performing. EVs will need to grasp at least one edge in the marketplace before they can feasibly compete for our wallets.

References

Battle of the Batteries - Gigaom.com

Technology Review

Battery technology is something I tend to take for granted. Without it, I couldn't run my car or my cell phone or my mp3 player or (heaven forbid) my watch. And the technology has come a long way since its invention in 1800; from Alessandro Volta's expansive setup of electrochemical cells all the way down to those button-sized pieces used in calculators.

As our world is becoming smarter and more mobile, batteries are becoming increasingly important. In the smartphone realm, sadly, batteries are having a tough time keeping pace with the race to the first handheld supercomputer. With bright displays, lots of processing power, and more capabilities in a small and lightweight package, smartphones fly in the face of everything good battery life entails. It's the only thing those flip-phone owners (me) can still brag about (besides lower phone bills).

Efforts to increase battery life usually revolve around finding new ways to decrease power consumption. But a new product in development by LG Chem is taking a different approach. The project is for "cable batteries", batteries made to be flexible like cables or wires. They are designed to work even when tied into knots or bent in any number of ways. The idea is to incorporate these batteries into headphones, phone cases, clothing, jewelry, and other on-person items and accessories in order to help charge or provide power for small electronic devices.

Making the battery starts with thin strands of copper wire coated with nickel and tin - two active electrode materials. The strands are woven into a yarn and formed into a strong spring to serve as the battery's backbone and anode. The other parts of the battery are wound around the anode, including an aluminum wire as the main component of the cathode. Next, the battery is drawn through a slurry containing lithium cobalt oxide cathode material and then dried. After being wrapped in protective layers, the product is completed by pouring in a liquid electrolyte used to carry charge when the battery is hooked up.

Currently, these batteries don't output a ton of energy. IG Chem says a 25 centimeter long prototype can run a small fourth generation iPod shuffle for 10 hours while in its bent shape. But compared to other flexible batteries that have been developed in the past, the discharge of these cable versions is relatively stable under stress. Also, previous types of flexible batteries were mostly made as flat sheets, which severely limitwwed their practical application. Cable batteries offer a lot more creative options for designers.

(A cable-shaped lithium-ion battery powers an LED display even when twisted and strained. Credit: LG Chem)

IG Chem hopes to boost the performance of these batteries as their work continues. Several design aspects, such as new anode materials currently being tested, could significantly increase efficiency and performance. Researchers at the company have high hopes, and say the technology could be ready for mass production in about five years.

I think this type of innovation has a lot of promise, especially for making everyday items "smarter". For instance, wearable electronics have been the focus of efforts to give sportswear the ability to monitor an athlete's health and performance during training. Considering the flexibility of the bendable battery design and the breadth if possibilities, this is just one of the potential applications that could be utilized in years to come.

References

Cable-Type Flexible Lithium-Ion Battery - Advanced Materials

Technology Review

Wind power has always been an interesting area of technology to look at, if for no other reason than the idea of harvesting "free" energy from something as simple as wind currents. But the technology itself is also pretty fascinating. Let's just say we've come a long way from old fashioned windmills…

From:

to

(Credit: Siemens AG, Munich/Berlin)

Here's a rotor blade of the world's largest wind turbine (5 MW) being transported to the construction site through a small town.

Make Way! (Credit: Siemens AG, Munich/Berlin)

Wind power has been a steadily growing renewable energy source in the U.S. over the last decade. In this time, improvements in technology have made wind turbines larger, lighter, and longer to increase efficiency and capacity. In 2011, wind power comprised 32% of additions to U.S. electric generating capacity. Unfortunately, much of this growth has stemmed from federal monies and tax credits such as the Product Tax Credit (PTC) and Advanced Energy Manufacturing Tax Credit. These are likely to expire by the end of 2012.

Some new projects in the country are still pushing forward, however. While all current wind energy in the U.S. is land-based (mostly located in the Midwest and Great Plains), some 20 offshore wind projects representing 2000 MW of capacity are in the works. This includes Cape Wind, a company that since the early 2000's has aimed to construct 130 wind turbines with a max capacity of 420 MW on Horseshoe Shoal in Nantucket Sound. Just last week the company received FAA approval for their project, which certifies the farm will pose no hazard to aircraft flying in the region.

Offshore wind provides a number of advantages over land-based generation, most notably higher average wind speeds. Noise pollution, loss in scenery, and injuries to birds are also not problems when building offshore. Cost is really the biggest problem, which is affected by construction, operation, and grid connection difficulties due to being located on the water. Specifically, there is no existing infrastructure for connecting offshore wind to the grid, so each project must create its own solution. And assembling these massive machines out on the water, as you can imagine, is not an easy task.

Still, Cape Wind and other projects like it promise lower electricity costs for their local customers through the 'price suppression' effect of renewable sources, which has been documented in Europe.

Despite all the incentives and apparent progress, wind power currently chips in only 3% of the nation's total electricity output, and its true economic sustainability will be realized a year from now if existing and startup wind projects are left on their own financially.

Cost-effectiveness has always been the question, specifically if the money used to build wind-farms could not be better used someplace else (such as insulating homes to reduce energy consumption and waste). The prospect of cost-effectively utilizing personal (residential) wind turbines is not yet an effective alternative either. At $6,000 and 400 kWh a month, it would take the average homeowner 12 years or more to make back the initial cost in energy savings. Safe to say, wind power still has a long ways to go.

References

Ars technica - Wind power

Boston Globe - FAA rules Cape Wind will not affect air traffic

Technology Review - A Mighty Wind Turbine

I always thought ice was pretty cool. We cool things down with it, skate and play hockey on it, make sculptures from it, and sometimes even fight evil mutants with it…

(Credit: X-men Wiki | The Adventurers Club)

But when dealing with a lot of technologies, ice is not so much fun. Icing (no, not the hockey penalty HUSH) is a big problem for roads, carbureted engines, wind turbines, air conditioners, refrigerators, planes, and electrical and telecommunications equipment. The buildup of ice can cause poor equipment performance or failure and can be a severe safety hazard in certain situations.

Icing Problems

A number of ice-related accidents and hazards are related to extreme weather. Those of us in the northeastern U.S. know particularly well the dangers and damage that ice storms can cause to roads and power lines. In these cases, the best we can hope to do is avoid the bad weather where we can, and have safety measures and procedures in place to deal with it when it comes.

But even in warm climates, certain technologies face icing problems during normal operation. For example, as airplanes pass through clouds on takeoff and landing, they can strike ice particles and cloud-borne water droplets that can be transformed into ice. Refrigerators and air conditioners can also lose their cooling capacity due to accumulated ice. In these cases, anti-icing technology would be a convenient solution.

(Credit: Ice accumulation on a rotor blade)

At GE Global Research in Niskayuna, NY, a team of scientists led by Azar Alizadeh is working on just that: anti-icing surfaces.

Understanding the Freeze

Research into ice-phobic materials has been going on for the past 50 years, but scientists say the limited level of success shows a lack of understanding of the fundamentals of water-surface interactions. This includes an understanding of the process through which water cools when in contact with a surface, the onset of ice nucleation, and the detailed nature of water layers adjacent to a cold surface.

By conducting freezing and heating experiments on a number of different types of surfaces, and using instruments such as a high speed camera and infrared thermometers, the team at GE pinpointed that surface structure (roughness) and surface chemistry (hydrophobicity) can dictate heat transfer as well as the rate of ice nucleation. These parameters have been the focus of new superhydrophobic anti-icing materials being developed by GE and other organizations.

One example includes SLIPS (slippery liquid-infused porous surfaces) aluminum developed by Harvard University. In a recently-published study, the material demonstrated resistance to icing in high humidity and cold temperature environments.

(<-- Still images simulating ice formation by deep freezing and subsequent deicing. Credit: Harvard University)

What's So E&E About It?

You may be wondering what makes anti-icing technology an environmental/energy topic. The reality is that anti-ice materials have the potential to save a lot of energy and reduce current dependence on certain chemical agents. In regards to aircraft, some 25 million gallons of deicing agents are currently used on planes taking off from U.S. commercial airports each year, and there is also a lot of energy wasted on electrical heating systems used for ice prevention in-flight. Using materials like the SLIPS aluminum for aircraft could eliminate the need for these chemical and heat treatments. Anti-icing materials could also potentially prevent failure and help maintain an effective cooling capacity for air conditioners and refrigerators in humid environments.

References

GE Scientists Demonstrate Promising Anti-Icing Nano Surfaces