Fine-Tuning Energy Consumption Through Ultracapacitors

Along with growing public interest in alternative energy resources, research and development in electric storage technologies may also hold the key to an energy efficient future.  For instance, electric double-layered capacitors, otherwise known as ultracapacitors, are playing an essential role in powering everything from small electronic devices to full-sized automobiles, allowing for fine-tuned precision in the use of the world’s limited energy supply.

The novel design of ultracapacitors gives them many advantages over conventional batteries.  Their most notable feature is that they store energy through an electostatic field rather than through chemical reactions, which allows them to charge and discharge energy at a faster rate than batteries do.  Whereas batteries tend to lose storage capacity over time, ultracapacitors can handle significantly more wear and tear in the absence of chemical reactions.  Ultracapaictors can go through 1000 times the amount of charge/discharge cycles that conventional batteries can, and often outlive the devices they’re meant to power.  In addition, they can function within a wide range of temperatures (up to -40C and +50C), and are composed of non-toxic ingredients that make them more environmentally friendly to dispose of than lead-acid or lithium-ion batteries.

What this means in practice is that ultracapacitors are ideal for accepting and/or delivering sudden surges of energy with little to no maintenance during their long life cycle.  Such is the case with ultracapacitors used in regenerative braking systems found in today’s hybrid vehicles, which transform a car’s forward motion into additional electricity when the brakes are used.  Ultracapacitors are also being utilized in this manner within smart-grid systems to absorb short circuits, provide critical backup power during outages, and to ensure uninterrupted communication to and from the grid during peak hours.

Currently, the majority (70%) of ultracapaictors are found in small electronic devices with low power applications, such as cell phones, digital cameras, and televisions.  However, they are also beginning to serve a larger role in alternative energy production through optimizing solar power storage and windmill pitch power.   Ultracapacitors have a better performance record than chemical batteries when it comes to delivering reliable power boosts that maximize the output of wind turbines; they are also able to function in extreme temperature conditions.  These qualities make ultracapacitors ideal candidates for alternative energy projects located places such as the scorching Mojave Desert, where the Alta Wind Energy Center (AWEC) and the Ivanpah Solar Electric Generating System (ISEGS)–one of the largest solar installations to date–are located.

Although ultracapacitors have been in development since the 1960’s, recent innovations in storage capacity and charging time have made them a more cost-effective technology capable of trumping conventional batteries in various applications.  For instance, in 2006, researchers at MIT’s Laboratory for Electromagnetic and Electronic Systems (LEES) developed carbon nanotube structures that increase the surface area of the ultracapacitor’s electrodes, which in turn increases it’s capacitance, or the amount of electric charge that it can store.    

Despite these advancements, advantages, and various applications, today’s ultracapacitors still face one major limitation:  their energy storage density.  While the researchers at MIT are confident that ultracapiactors will have the same energy storage density as chemical batteries sometime in the future, current ultracapiactors can only store approximately 5% of the energy that comparable lithium-ion batteries can, making them unsuitable for applications that require prolonged use.

Although ultracapacitors in the near future will more than likely not be replacing conventional batteries as a whole, they can still work in the present to prolong the life of conventional batteries, saving valuable resources that would go into replacement and maintenance costs.  For instance, they are currently used in conjunction with lithium-ion batteries found in electric vehicles (EVs) to provide the sudden bursts of power needed for acceleration.

Yet within the span of decades, it’s possible that the lucrative promise of ultracapacitors may replace lithium-ion batteries in EVs altogether, in that they provide EVs with the fast charging time needed to compete with standard petroleum vehicles at the gas pump.

Overall, the advantages of ultracapacitors far outweigh their costs and shortcomings.  They optimize and fit nearly into already existing infrastructure, require little maintenance, and function for long periods of time with minimal environmental side effects.  This makes them a viable alternative to other energy-related investments, such as hydrogen and ethanol fuel, which require extensive resources to produce, and/or new technological infrastructure to function.

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Coastal Fish in Gulf of Mexico Recover After Oil Spill

Populations of coastal fish along the Gulf of Mexico seem to be relatively unscathed after the 2010 Deepwater Horizon oil spill, according to recent research published in the international online journal PLoS ONE.

The research comes as a joint effort from marine ecologists at the University of South Alabama and the University of North Carolina at Chapel Hill, who discovered that there has actually been an increase in the number of juveniles found in at least 12 of the 20 species of coastal fish studied since the disaster occurred.  Overall, the species-by-species catch rates of coastal fish recorded within a five-year data set went from (1,080±43 fishes km-towed−1 [μ ± 1SE]) in 2006 to (1,989±220 fishes km-towed−1 [μ ± 1SE]) in 2010.

This increase appears despite the fact that vulnerable larvae have been exposed to oil-polluted water, which contains toxic contaminants such as polycyclic aromatic hydrocarbons (PAHs).  PAHs are known to result in genetic damage and physical deformities, and can alter or delay the developmental onset of adulthood in fish eggs/larvae.  These same PAHs are responsible for causing sickness and even death amongst workers involved in the aftermath of the oil-spill clean up efforts.

For many, including the researchers themselves, this news comes as a surprise, considering that the explosion at Deepwater Horizon caused the largest accidental marine oil spill in the history of the petroleum industry–reportedly 20 times greater than the Exxon Valdez oil spill in Alaska in 1989.  Between the months of April and July 2010, the collapsed drilling rig gushed 4.4 million barrels of crude oil at a rate of 53,000 barrels a day over a protracted 84 day period.  In addition to spilled oil fouling hundreds of miles of sea water, the initial explosion at the Macondo Prospect killed 11 workers, with many more hospitalizations of local residents and workers occurring during clean-up efforts due to high levels of exposure to dangerous carcinogens.

The researchers suspect that the main reason these coastal fish have avoided catastrophe is due to the fact that much of the oil released did not rise to the surface; instead, it emulsified at the well head and throughout the water column, allowing the majority of spawning coastal fish to become resilient enough to survive the oil’s effects.

Other factors may also be contributing to the apparent stability of these coastal fish populations, including a reduction in the number of major predators who eat their juvenile fish and larvae, which is also a result of the oil spill.  Coastal fish species may also be uniquely resilient to oil pollution “due to their mobility or foraging ecology.”  Lastly, a release from harvest pressure due to fishing bans in about one-third of the Gulf after the oil spill may account for increased spawning activity, although no significant statistics were found to prove this.

Even though researchers admit that “these data provide reason for early optimism,” the good news should be taken with a grain of salt, in that “attention should now turn to possible chronic effects of oil exposure on fishes,” as well as any “delayed indirect effects” which may not be seen until years after oil exposure.  Such was the case with the Exxon Valdez oil spill of 1989, which resulted in Alaskan coastal wildlife being exposed to residual sub-lethal levels of toxic oil up to 20 years after the initial incident.

In the case of Deepwater Horizon, the early concern over the Gulf of Mexico’s coastal ecosystems will likely shift towards a long term study of the spilled oil’s effects in the the deep ocean, where the majority of it is found today.

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