Energy Storage


Energy storage‘ can refer to either the process of saving some form of energy for later use, or the physical infrastructure required to do so. Energy is critical to every accomplishment of humans. This energy can take many forms. If you are interested in only specific forms of energy, you can click on a section of this document by viewing the table of contents to the left. 

Energy storage is very useful for the stable function of a power grid. Inevitably, power stations have to be serviced or have failures. Even failures that are a fraction of a second can be disastrous for certain applications, such as monitoring systems for heavy machinery, computers, and other sensitive electronics. Stability of power is a key factor in the design of an effective power grid. Stability requires that there be backup systems in place in case of a baseload power failure. Energy storage  is required for most backup systems to be effective.

It is not feasible to ramp up a coal or nuclear power plant to meet demands in a matter of minutes if the situation arises. They are designed for constant output, not for meeting the exact current demand.  Hydroelectric power is much better suited for quick adjustment to energy demands. The energy storage ability of hydroelectric dams depends on the amount and height of water contained on the reservoir side of the dam. The water has stored energy because gravity is trying to pull it down. As the water falls, we can extract energy out of it by having it spin a turbine to create power. This is the same concept as water falling on one side of a water wheel, causing it to turn.

Notable Forms of Energy Storage

Hydrostatic

Water raised to a height is known as hydrostatic energy storage. It is the most common form of mass energy storage in the world. This is due to the fact that compared to other forms of energy storage, it is widely available and easily utilized. This is one of the major reasons that humans construct many hydroelectric dams so that large reservoirs form on one side of them. The reservoir represents a huge amount of water that is waiting to be used for energy production. Unfortunately, hydrostatic energy storage is only feasible in areas that have changes in ground elevation coupled with large flows of water. It is thus difficult to build large-scale hydrostatic energy storage on the prairies.

Pumped Hydro Storage

Especially useful are natural ground formations that can hold water at a higher altitude than another nearby body of water. During times of high demand, water can be run down to create electricity. During times of low demand, when electricity is being cheaply produced from baseload sources, water can be pumped from the lower body of water to the higher body of water. This action would store energy by raising the water to a higher height.

Compressed Air

Compressed air is a form of energy storage that is starting to receive more notice. It is beginning to look feasible for both large scale and small scale systems. On the small scale, a house could power itself off a compressed air tank for a certain amount of time. On a large scale, deep wells into the ocean or geological cavities can provide ways to create enormous pressures of air in a stable environment. This technology has existed for a while but has never been used for large scale energy storage. Drawbacks include the possible remoteness of these well pipes, the newness of the technology on a large scale, and construction cost.

Chemical

This is currently the most widely used form of energy storage for small to medium scale systems. This includes gasoline, jet fuel, hydrogen and food. Chemical storage in general has extremely high energy density. This means that a large amount of energy can be stored in a small amount of space, and with a small amount of mass. Despite their drawbacks, hydrocarbons are still incontestably the best mobile energy storage we have right now. We know how to store and use them well, as well as having the infrastructure in place to do these things. The fact that they release carbon dioxide when burnt would not be important if they were part of a carbon-neutral cycle. For instance, creating hydrocarbons out of plants that have just been grown would in theory be a net zero in terms of CO2.

Nuclear

Nuclear energy is naturally stored. We need to bring nuclear active materials close together in order to cause an increase in the rate of their natural energy emission. The more densely they are packed, the more ‘active’ they become. Incredible safety measures are evident in nuclear power plants because of this.

Some current and future reactor designs have the ability to operate from 50-100% capacity, effectively being able to operate as peaking generators.

Small Scale

Mechanical

Anything that is in motion is mechanically stored energy. This is technically kinetic energy storage. A flywheel is a form of mechanical energy storage. Also the stretching of a solid is a common form of energy storage. Certain types of catapults in the middle ages, as well as slingshots and bows demonstrate this type of energy storage.

Hydrocarbons

Hydrocarbons are the dominant method of small-scale energy storage for several reasons. First of all they have a very high energy density. This means that they can store the most energy per volume of all the storage methods other than nuclear. A general comparison is that one litre of gasoline can do more work than 50 pairs of human hands working for 24 hours. Hydrocarbons are easy to utilize because we historically have used them extensively.

Hydrogen

Current hydrogren storage systems have a low energy density so far. This means that it is currently less suitable for transportation needs than hydrocarbons, but will function well for static use. The main problem with hydrogen is low conversion efficiencies, leading to expense. Hydrogen is at a disadvantage when compared to hydrocarbons because it is energy intensive to create, problematic to store, and sports a low energy density per volume. An enormous advantage to hydrogen is the fact that its combustion with oxygen produces only water. This means that hydrogen might be the ultimate fuel in many respects since its by-products are non-existent or extremely benign. The Hydrogen economy ideas have been worked on for many years, but no suitable method for storing hydrogen has been presented. If we cannot store hydrogen effectively, then we cannot use it for small-scale applications extensively because many of these applications involve mobility. If we need to haul a huge hydrogen tank everywhere we go with our car, it might not be as environmentally friendly as we would like.

Batteries

Batteries are also a very popular form of small scale energy storage for low-energy demand applications. Many forms of consumer electronics rely on batteries. Laptops, cell phones, PDAs, MP3 players and automobiles all use batteries. In general batteries are good for systems that need well controlled but small amounts of electrical energy. They do not have the energy density of hydrocarbons, but their energy is designed to be converted directly into electricity, which is not usually the case with hydrocarbons (which are usually used mainly for mechanical energy in small scale applications).

Capacitors

Capacitors are very fast charging, but their energy density is generally accepted as being too low for widespread use. New capacitor designs are being built that have energy density on the same order of magnitude as batteries. This is a significant technical advancement since capacitors can usually be charged and discharged millions of times with no damage to thier function, unlike batteries.

Kyle Laskowski

I am a graduate from the University of Regina’s Honours Physics program from rural Saskatchewan. After taking a keen interest in the Saskatchewan Uranium Development Partnership consultation effort, I have become interested in studying and writing about a diverse range of topics, as you seen on Vision Of Earth now. Recent additions to my interested include machine learning, space flight and our future relationship with Mars.

11 thoughts to “Energy Storage”

  1. Thank goodness Swift’s satiric notion of eating babies wasn’t socially acceptable… Or that ridng horses was… Or that vegetables…
    You get the picture.

    Whether something is socially acceptable is an extremely poor basis for such conclusions re: nuclear power, wouldn’t you say?
    Why is it that people for or against somethng seem to think they are right just because someone has simply stirred up hornets?

    Curious that while young Kyle admits that fossil fuels for power generation are less desireable than nuclear options, he does not advance any real science to demonstrate either the effectiveness or efficiency of other alternatives that would or even could meet demand by current commercial or industrial users…

    Is not science – at least – supposed to be neutral!? Or perhaps innocent until proven guilty?

  2. I do not believe the use of social coercion is the best way to put forth energy options such as nuclear power, that are so feared and misunderstood by the public. I am not saying that public fear and ignorance of the full complexity of pro or anti nuclear arguments should be a basis to ignore such technology, but I do believe that such a situation should be responded to with further, unbiased, education. Providing only one side of the nuclear story does no good in currying public favour.

    In a society that considers itself based on personal freedoms, forcing solutions that doesn’t have the backing of its citizens is foolhardy. To illustrate this point, I will use the former French Superphénix breeder reactor as an example. While favour for the widespread use of nuclear power in France must be higher than here, a terrorist rocket attack was launched on it during construction by anti-nuclear activists. I’m not saying that higher public acceptance would necessarily stop fringe groups from attempting such actions, but it would have made punishing such actions easier for the government of France.

    http://en.wikipedia.org/wiki/Superph%C3%A9nix

    I believe it is immoral to spend large quantities of tax dollars supporting technologies that your citizens are against without attempting a substantial education campaign, finding what true reasons the people are against it and helping to erase the myths other may be clinging to. In such a truthful campaign, even some formerly pro-nuclear people may switch sides once they were truely aware of what risks and costs it entails. That is the cost of a truthful dialogue with your citizens.

    The use of nuclear, wind, or solar combined with compressed air, hydrostatic, or other methods of energy storage is very capable of supplying the demands of large scale users using today’s technology, it is the complexity and associated higher cost that stalls the implementation of such things. A lot of people critical of low carbon energy sources cite the fact that these energy options are not yet as cheap as coal as a reason that they are unsatisfactory, but it will take a substantially honed technology to produce electricity cheaper than an already established industry of effectively burning flammable dirt.

  3. In addition to agreeing with Kyle’s response, I’d like to say something about the comment “Is not science – at least – supposed to be neutral!? Or perhaps innocent until proven guilty?”

    Regardless of what you may think science is “supposed to be”, it has never been and will never be politically neutral. Science is not conducted in a vacuum (insert Torricelli joke here), it is a social activity and pertains to society’s past and future. If it did not (which would be impossible), it would be irrelevant.

    Actually I hear this argument all the time and am convinced that, unless you are extremely naive, you are using it as an excuse for why society should further conduct YOUR view of science. Thomas Kuhn pointed out as much in his book “The Structure of Scientific Revolutions” over forty years ago.

    More controversially, I would suggest that scientific programs should not even be given the benefit of presumed innocence. Weapons researchers and marketing psychologists use this one often: “It wasn’t us who pulled the trigger or pressed the button!”, “It wasn’t us who sold the high fructose corn syrup to the toddlers!”

    “Innocent until proven guilty” works well for the legal system because there is less harm done to society as a whole if we let an individual murderer go free than if we execute an innocent man. It does not work well for science, because obtaining “proof” that a scientific program has harmed or will harm society is much more difficult, and the societal risks much larger.

    CFC’s were no doubt originally considered “good” for society by providing efficient refridgeration for the masses, but we now know enough to have banned them. Unfortunately, in the interim serious damage was done to the ozone layer.

    On the other hand, does global climate change need to be proven beyond “any reasonable doubt” before we realize the danger of overconsumption of carbon-heavy energy sources? Presumed innocence of coal-fired power plants and mass-produced gasoline-powered cars may well come round to bite us in the ass, as we are currently discovering.

    Instead we should be putting MORE resources into scientifically investigating the ramifications of our actions as a scientifically advanced society. The best science available to us, honestly communicated to the public and government officials in a timely manner, is the only way we can move forward responsibly. Too many of our resources are currently being devoted to immediately “profitable” scientific research, while programs to gauge the environmental and socioeconomic consequences of these discoveries are neglected or suppressed.

    This will of course in no way guarantee our success as a society, but to do otherwise would be irresponsible.

  4. Pingback: Wind Power
  5. Planet of Earth Energy Crisis.

    Dear Sir

    Subject mater all our the World facing Energy problem So I am try to explain a idea for Old & New Dams / Reservoirs Hydel Civil Design can move in architectural Transition to increase our energy potential Because we are losing heavy quantum of already storage water in our Big Dams to generate past technology now need to convert into New theory of Technology.

    Thanks.

    with best regards.

  6. Dear Sir,

    The Subject matter is all over the World facing Energy problem, So I am trying to
    Explain an idea for Old & New Dams / Reservoirs Hydro electric projects Civil Design Geometry
    Can be modifying in Architectural Transition to increase our energy potential. Because we are
    Losing heavy quantum of already storage water in our Big Dams and its relevant projects to generate Hydro Electric old technology, Now it must be need to convert into new theory of Scientific Technology as per utilizing in the way of experiment with foreign expertise at any Hydro electric base Model of concern Department or forum to finalize the following unique and entire world Globalize developing idea for its further implementations in the current ongoing and next coming future Hydel projects as soon as possible.

    Thanks.

    with best regards.

    RE: Planet of Earth Energy Crisis.

    Dear Sir,

    Thank you very much for your interest in proposed idea consideration, Due to other sectors & individuals responses take to my self need to be consult a proper forum regarding the situation now I am able to communicate with your good self. Also sorry for some days delaying answer from my side.

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    4. It doesn’t mean that my self have no proper proposal for describing because this one is a serous issue for entire world to escaping the current energy crises.
    5. Mechanism / Methodology of idea to implement with Design criteria must be Liaise in near future as well as your kind and positive action.
    6. My self keep this idea to preventing not go towards wrong ways, Sir your good self know better to me very well. Because after all it is the property of whole world and its creatures, Which will be fully utilize upon when enhance the capability of electrical energy generate according to the new term of way.

    Sir about my CV.

    My Name is Shabbir.
    Qualification: School certificate.
    After this go toward Technical Course for Surveyor in 1982.
    Then start as Land Surveyor Jobs in different Companies in Pakistan.
    During in 30 years jobs mostly work on Topographic & as built Surveys.
    Observations & Knowledge come through different Projects and Sites in the due course of my whole life.

    Thanks.

    Hoping for a positive response will be coming soon as well as your good self reply.

    with best regards.

    Shabbir (Land Surveyor)

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