Redox Flow Batteries: For Grid Level Storage

 

by Chad Redman

Current energy storage technologies are often overlooked in favor of the next promising development that will be commercialized sometime in the future, but economical large scale energy storage is already possible with current equipment. Redox flow batteries (RFBs) are a type of large battery that utilizes reduction and oxidation reactions to charge and discharge liquid electrolyte solutions. The advantage of RFBs over other battery types is realized in scale; RFBs can easily expand and store more energy by using larger storage tanks for the electrolyte solutions. However, the power that can be produced by an RFB is determined by the architecture of cells within the RFB. Unlike a standard Li-ion or lead-acid battery, only a small percentage of the energy within an RFB is accessible as power at any given moment. Continue reading

SolePower: Solving the Mobile Energy Problem

by Shannon O’Neill

Advancements in technology, specifically in handheld devices and portable electronics, are increasing at a rapid rate. Because battery technology and advancements have been moving at a much slower rate, the use of these devices has been limited to their battery life. This issue motivated engineering students from Carnegie Melon University to develop SolePower, a rechargeable battery that is powered and charged when the user walks.

A special insole (or “ensole, for energy insole) is placed in the user’s shoe. The mechanism inside the insole is able to capture the kinetic energy produced when walking, which is then used to spin an electromagnetic generator as fast and as long as possible. The power created is then stored in an energy pack, which can be stored on top of the user’s shoe or on the users ankle. This energy pack can then be hooked up to cell phones or other portable devices and used a portable battery. Currently, an hour walking provides enough energy to sustain two and a half hours of talk time on a cell phone, with a walk between two and a half to five miles providing a full charge to an iPhone. Continue reading

An Upcoming Method of Energy Storage

by Alex Elder

California is currently in the forefront of clean energy production, not only in the United States, but in the world. Although their rising production of wind and solar energy yields many benefits for the state and its residents, it also produces some unprecedented problems. Specifically, the increase in energy generation results in complications for managing the electric grid which has to maintain the balance of energy supply and demand. The strain on the grid has resulted in a technological movement to improve energy storage systems which would help relieve some of the issues associated with increased energy production. Because energy storage systems are designed to store and then quickly release energy onto the grid, they are able to prevent a potential supply imbalance which can sometimes be caused by the sporadic influx of solar and wind energy. Battery-based storage systems in particular can store energy from the grid when electric rates are low and discharge it for use during the day. This kind of system is especially useful for banking solar energy, which can then be used at night or when power from the grid is more expensive at certain times of the day. Continue reading

Redox Flow Batteries: For Grid Level Storage

by Chad Redman

Current energy storage technologies are often overlooked in favor of the next promising development that will be commercialized sometime in the future, but economical large scale energy storage is already possible with current equipment. Redox flow batteries (RFBs) are a type of large battery that utilizes reduction and oxidation reactions to charge and discharge liquid electrolyte solutions. The advantage of RFBs over other battery types is realized in scale; RFBs can easily expand and store more energy by using larger storage tanks for the electrolyte solutions. However, the power that can be produced by an RFB is determined by the architecture of cells within the RFB. Unlike a standard Li-ion or lead-acid battery, only a small percentage of the energy within an RFB is accessible as power at any given moment. Continue reading

Just Released! “Energy, Biology, Climate Change”

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Our newest book just Released! “Energy, Biology, Climate Change” and available at Amazon.com for $19.95.

The focus of this book is the interactions between energy, ecology, and climate change, as well as a few of the responses of humanity to these interactions. It is not a textbook, but a series of chapters discussing subtopics in which the authors were interested and wished to write about. The basic material is cutting-edge science; technical journal articles published within the last year, selected for their relevance and interest. Each author selected eight or so technical papers representing his or her view of the most interesting current research in the field, and wrote summaries of them in a journalistic style that is free of scientific jargon and understandable by lay readers. This is the sort of science writing that you might encounter in the New York Times, but concentrated in a way intended to give as broad an overview of the chapter topics as possible. None of this research will appear in textbooks for a few years, so there are not many ways that readers without access to a university library can get access to this information.

This book is intended be browsed—choose a chapter topic you like and read the individual sections in any order; each is intended to be largely stand-alone. Reading all of them will give you considerable insight into what climate scientists concerned with energy, ecology, and human effects are up to, and the challenges they face in understanding one of the most disruptive—if not very rapid—event in human history; anthropogenic climate change. The Table of Contents follows: Continue reading

Automated Electrified of Cars and Sustainability

by Tyler Dean

Automated vehicles increase vehicle and change the economics of alternatively fueled vehicles. This makes them the cheapest transportation and manufacturing option in the long term. Through automated vehicle fleets used as “point-to-point on-demand car clubs”, we increase the total availability of transport services and make the benefits of alternative fuel and automated vehicles available to a larger potion of the global population. The downside to electrified vehicles and automated vehicles are range anxiety and the loss of the driving experience. With complete adaption, the range anxiety is concurred by specialized distance transportation and by the mass majority of society adapting to method because of the benefits of utilizing their time more efficiently while transporting. Continue reading

Lithium-Air Batteries: The Next Battery Revolution?

 

by Chad Redman

Energy storage technology is a fascinating field of research, boasting numerous potential replacements for the current cutting edge of battery technology – lithium-ion chemistry. One promising and widely researched alternative to lithium-ion batteries is the lithium-air battery. Lithium-air battery technology became widely known to researchers in the field in 2009, and has been the subject of over 300 research papers since 2011. The primary benefit of lithium-air technology is increased energy density; if fact, lithium-air battery technology has the potential to bring electric vehicle range up to competitive levels with internal combustion engines (Girishkumar et al., 2010). Lithium-air batteries with non-aqueous electrolytes (oxygen gas) can theoretically produce up to 3500 watt hours of energy per kilogram, or 1700 Wh/Kg in practical application (Kwabi, et al., 2014). Continue reading

Used EV Batteries to Stabilize the Grid

by Emil Morhardt

If a single used electric vehicle (EV) battery, still functional but with it’s storage capacity degraded by 20%, could be used to store energy from photovoltaic panels at home (see Dec 30 post), a bank of them could be used to stabilize the whole grid, according to Gillian Lacey and colleagues (2013) at Northumbria University in the UK. Their particular emphasis is “peak shaving”—supplying enough electricity at times of peak demand that additional fossil-fuel generation can remained turned off. This would also help regulate the line voltage and allow some “upgrade deferral”­—putting off investing in needed new or more efficient sources of energy. A particular value of this type of storage is that it would be at the low voltage end of the distribution system, closer to the end user, thus decreasing the potential line losses that would occur if peak power were supplied by regular generation systems, and increasing the life of transformers which are particularly stressed under peak loads. This might also mean that this type of storage would be “distributed”—maybe one battery per residential transformer. Since most large-scale current photovoltaic generation stations generate at low voltage, used EV batteries might be useful there as well. Continue reading

Fast Discharge Batteries: Electric Eels

by Emil Morhardt

We write a lot here about electric batteries of various sorts, but one of the oldest ones is the 600 Volt biological battery of the electric eel Electrophorus electricus. These animals search about for hidden prey by emitting a couple of high voltage pulses from time to time to see if anything jumps. If it does, they sidle on over and cut loose a volley of high frequency (~400 Hz) pulses that the muscles of the prey apparently interpret as coming from their own nervous system. The result is many muscles contracting simultaneously, paralyzing the prey into a state of whole-body muscle contraction known as tetanus (similar to the eponymous disease) and the eel sucks them in. This all happens pretty fast, on the order of milliseconds. If the eel fails to suck them in they often just swim away. Continue reading