Why Ultracapacitors Belong in the Renewable Energy Value Chain

Some popular sources of renewable energy, including wind, wave, and solar energy sources are notoriously variable in their output and generation. This variability is characterized by short duration and high amplitude, and carries with it high intrinsic costs.

Stability, and more importantly, predictability in energy flow, is important in all applications. Instability in renewable sources invariably results in poor efficiency at many levels. This drives large hard-dollar expenses and a multitude of soft costs such as unreliability and inefficient architecture impacts.

Fortunately, ultracapacitors provide a ready solution to address this variability. The needs of these renewable resources perfectly align with the capabilities of ultracapacitors. By now, most engineers are starting to appreciate the strengths of the ultracapacitor: high-rate charge and discharge capability with a long lifetime. Energy smoothing, firming and stabilizing are all terms that open a discussion about ultracapacitors during the system design phase of a particular project. It is the unrivaled power delivery capability of ultracapacitors that make them an unparalleled solution for smoothing, firming, and stabilizing applications.

Therefore, it is incumbent for the systems engineer to design ultracapacitors into the system to address these stressful variable conditions. Those with the foresight to make this design decision will be rewarded with a system that operates successfully for the life of the application with trouble-free service functioning at a high level of performance. Conversely, those who elect to address the problem of variability with an ill-fitting solution will ultimately suffer the effects of high maintenance costs, repetitive replacement costs, and ever-present operational inefficiencies.

With ultracapacitors in the renewable energy value chain, renewable resources can increase and improve the quality of outputs, experience lower overall project costs, and optimize performance. So, why don't ultracapacitors show up in every renewable energy storage system? Don't worry — they will.

Have you seen any renewable energy projects that could've benefitted from ultracapacitor technology? Tell us in the comments.

26 comments on “Why Ultracapacitors Belong in the Renewable Energy Value Chain

  1. samicksha
    June 17, 2014

    I read about a hybrid electric bus called tribrid which i guess was unveiled in 2008 by the University of Glamorgan, for use as student transport. It is powered by hydrogen fuel or solar cells, batteries and ultracapacitors.

  2. etnapowers
    June 17, 2014

    I guess that a smart management of the energy stored in the ultracapacitor might further increase the autonomy of the Tribid, that sounds as a very interesting solution to me.

  3. MAEverett
    June 17, 2014

    Any system that has a “signfiicant” power and energy split potential will find ultracapacitors can be put to good use.  Significant has to be so through the eyes of the architect and in light of the application, but this one is a perfect candidate given the power demands in a vehicle are undeniably significant. And as vehicles go the tribrid architectures are no exception. coupling multiple sources of energy with no pure power provider is only accentuating the glaring ommission. Let the UCAPS add lifetime, reliability, performance and efficiency to the system and the concepts of advanced hybrid vehicle architectures will open up with substantial flexibility and capability not before realized.

  4. samicksha
    June 18, 2014

    I agree you @etnapowers, Compared to batteries, they have a low internal resistance, hence providing high power density capability. May be in future we can see more good examples like Tribid being used on large scale.

  5. Davidled
    June 18, 2014

    I image that ultracapacitors might be located in the control module that executed the energy management using alternative energy source. I am wondering how much ultracapacitors contributes to save the energy in the electric bus.

  6. David Ashton
    June 18, 2014

    Where ultracapacitors would be really useful is in Solar electricity (PV) applications – to store energy acquired during the daytime for use at night.  We're beginning to see battery-based systems that do this but they are very expensive and batteries have a finite life.  Do you foresee ultracapacitors taking over from batteries in this application anytime in tthe near future?  If we could get to this capacity, the off-grid suburban house might become a reality….

    PS sorry, Mike, just read your blog on Ultracapacitor energy storage on the Grid .  Doesn't answer my questions but does give the current state of play – ie Caps have very much less (like 1/75) than battery capacity but are good for helping smooth out demand on batteries.   So my question still stands – do you think that UCs will be able to take over from batteries anytime in the foreseeable future? 


  7. Jonathan Allen
    June 18, 2014

    One difference between a capacitor (ultra or not) and a battery is that the latter maintains nearly constant voltage throughout its discharge, while the capacitor's voltage drops.  This means that any inverter or power conditioner must adapt continuously to the wide voltage variation.   Certainly possible, but one more enginering problem to solve. 

  8. samicksha
    June 19, 2014

    I dont think ultracapacitor taking over batteries any time soon, as they have low per cell voltage and for most applications a higher voltage is needed, the cells have to be connected in series.

  9. David Ashton
    June 19, 2014

    @Samicksha… “as they have low per cell voltage and for most applications a higher voltage is needed, the cells have to be connected in series .”

    Well, yes, but the same applies to a similar degree to batteries. There are different problems connecting UCs in series but they should be solvable.  The main issue appears to be capacity, and that does nto seem to be solvable any time soon?

  10. Davidled
    June 19, 2014

    Vehicle battery would be changed by Ultracapacitor as Ultracapacitor has been developing if Ultrcapacitor are used in order to store the energy similar to battery chemistry action.     

  11. Netcrawl
    June 19, 2014

    @Daej ultracapacitors proved to be superior to the incumbent battery, far more reliable and could perform far beyond the battery's limitations. They can maintain a high level of performance in cold temperatures and have a very long life. Its high level of performance and long life make them the ideal energy storage for renewable energy.

    They can also create a far more realible system for emergency type situations, they only require some good protection for moisture, inexpensive balancing circuitry and a designed charge to maximize their life,  

  12. chirshadblog
    June 19, 2014

    @DaeJ: Do you mean to say that it's a copy or a duplicate ? 

  13. chirshadblog
    June 19, 2014

    @samicksha: Yes just the brand name will not do it. You do need the skilled people as well as the knowledge to back you. 

  14. Netcrawl
    June 19, 2014

    @samicksha, I think its possible, ultracapacitors not only charge faster they also last longer because the physical toll in charging that wear down the batteries and then they have these safety advantages. Remembered the Boeing incident, its one of the worst tragedies trace to battery failure.  

  15. Netcrawl
    June 19, 2014

    @David I agree with you, ultracapcitors can help combat solar grid challenges, they can provide a reactive power in cost-effective and smaller package size, its long life, superior cahrging discharging cycle make them well-suited for firming the output of solar installations. 

    @David I think its possible ultracapacitors replacing batteries, GE has already developed a truck with ultracapacitors replacing the battery and I believe something similar has occured in some power tools. 

  16. Davidled
    June 23, 2014

    Ultracapacitors could be used in order to save energy and reduce carbon mission as long as long operational life and low maintenance requirement are meet. I think that they could charge and discharge energy very quickly compared with battery. The integration of two energy sources could be worked very well in vehicle applications.

  17. chirshadblog
    June 24, 2014

    @DaeJ: If so how about the fuel consumption? I think it will be a bit high than the normal isn't it ? 

  18. geek
    June 25, 2014

    “. The integration of two energy sources could be worked very well in vehicle applications”

    @DaeJ: I think that's how the application of UC is likely to be in the future. It shall be used along with batteries because the latter provides more reliability to it. Particularly in critical applications where reliability is a must-have, this is going to be quite important.

  19. SunitaT
    June 29, 2014

    @Daej, Ultracapacitors will be useful in the situation like waiting in traffic. With the short burst of energy supplied by Ultracapacitors we can restart the engine immediately thus saving the fuel.

  20. SunitaT
    June 29, 2014

    Capacitance is used to store the precharge voltage in DRAM memory cell. Can the property, restoring precharge voltage, of conventional capacitors replicated in Ultracapacitors?

  21. etnapowers
    July 1, 2014
    “Let the UCAPS add lifetime, reliability, performance and efficiency to the system and the concepts of advanced hybrid vehicle architectures will open up with substantial flexibility and capability not before realized.”
    True. the supercapacitors might be inserted in all the systems that are feeded by multiple renevable sources , demanding stable power. I think that the reliability of the supecapacitor is a key point , being this component very new to the market, its robustness to the harsh environment in which it might operate, has to be enough to guarantee the overall system reliability.
  22. etnapowers
    July 1, 2014

    Yes, I guess that many solutions like Tribid will be realized, once the hydrogen fuel technology will be fully developed and qualified for a large scale production. Moreover I think that it's desirable that experiments like the one performed by the Stanford students about the development of a solar powered car will lead to a large scale solution, as you said.

  23. Davidled
    July 1, 2014

    These could be applied to hybrid or electric vehicle as expecting fuel economy improvement. The ratio of improvement could be variable according to the voltage level of ultracapacitor applied to vehicle.

  24. samicksha
    July 2, 2014

    another aspect is making this fuel easily available to end user and educating him on technology.

  25. etnapowers
    July 2, 2014

    @samicksha : that's correct. The diffusion of a technology strongly depends on the perception of the users of the advantages (mostly economic advantages) of the solution proposed and from the marketing campaign that has to put in evidence its most important aspects.

    An easy access to the fuel sources is another key point, the price of the fuel is very important to make the difference between the success or the flop of the solution proposed.

  26. Davidled
    July 7, 2014

    It sounds like this capacitor could be more useful for urban city cycle which generates the stop- and- go behavior of vehicle rather than highway. When stopping the vehicle, capacitor would be charged from vehicle and this energy could be used when vehicle is starting.

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