Tasmanian Times

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche

The individual has always had to struggle to keep from being overwhelmed by the tribe. If you try it, you will be lonely often, and sometimes frightened. No price is too high for the privilege of owning yourself. ~ Friedrich Nietzsche

Economy

Is this the Quantam Leap in Renewable Power Storage … ?

*Pic: Arvio’s Paul Wilson demonstrated the capacitor technology – Vimeo clip – Glen Morris.

Over the past several years Lithium has been the buzz-word for renewable energy storage. However a new innovation using carbon capacitor storage has broken beyond the barriers of that technology.

Arvio, a Victorian-based company has engineered a new power-storage, inverter and communication system, and will be soon commercially supplying ones that perform far beyond the current lithium or lead acid battery range.

Arvio’s new capacitor energy storage system is revolutionary considering it uses materials that are recyclable and biodegradable.

The power storage retained in Arvio’s capacitors is composed of carbon/graphene particles wrapped in paper encased in aluminium.

Present lithium battery storage systems are estimated to last up to 15 years with about 5000 cycles. The new Arvio capacitor system is estimated to provide around 1 million cycles with an audacious claim of a lifespan of over 2000 years.

The Arvio storage systems can be used with single or three phase systems and is inverted at 48 volts.

They can be totally transportable in cabinets, and linked to Internet systems to control power supply from an application within your remote-distanced computer or phone.

The Arvio systems have incredible scope for local and remote power storage capacity.

Here are some the Capacitor’s operational specifications …

• 1,000,000 cycles

• 100% rapid charge and discharge with no degradation or cycle reduction

• A 3.55kWh capacity is 3.55kWh usable

• 96% DC to DC round trip efficiency at the terminals

• Charge and discharge at 2C with no effect on cycle life or capacity

• Safe with no risk of thermal runaway

• Doesn’t get hot when charging or discharging

• Cells operates from -30°C to 85°C without need for added cooling systems

• Works is unlimited parallel

• No chemicals or liquid

• Non toxic

• Not volatile

• 10 year warranty – 45 year cell design life

Vimeo – http://www.solarsquad.com.au/quantum-leap-battery-storage-arrived

Introduced at the 2017 All Energy Conference in Melbourne, the initial commercial shipments of the world’s first supercapacitor based energy storage system are landing in Australia April 2018.

Like many new techno innovations the proof will be in the pudding once this system gets out into the working environment. Will it overtake the current Lithium market, or will it under perform?

There are numerous renewable storage designed batteries currently commercially available, and all indicators suggest that the traditional lead acid type will be less prevalent in the future even though they are cheaper. Here’s what’s happening in the testing and analysis field.

Holy battery advice, it’s Batt Lab!

Note that none of these products are made in Australia.

The Avrio supercapacitor is presently more expensive than the Tesla product, yet there is the potential for this to change energy storage systems well into the future.

*Ted Mead, over the past several years, has been observing the renewable energy technology advancements with great interest and admiration. Ted believes the world in the next decade will make monumental leaps in design and infrastructures that will transform us out of the old fossil fuel reliance into to a new paradigm that functions on a responsible energy footprint across the globe.

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27 Comments

27 Comments

  1. Steve

    April 9, 2018 at 9:51 pm

    I can’t see there’s too much wrong with the theory of using capacitors for storage. Capacitors will indeed hold a charge. The problem is a question of scale.

    To add to the information that Peter has supplied above, capacitance is measured in Farads. Most real life capacitors are measured in micro or pico Farads – ridiculously small portions of the base unit.

    A capacitor is created by having two conductive sheets with an insulating layer in between. I did a rough sum based on two conductive sheets separated by a layer of glass the thickness of glad-wrap (12µm). To achieve 1 Farad, the area required would be 45 ha!
    That 1 Farad, charged at 48 volts, using Peter’s equations, would hold 0.5 x 1 x 48² J, or 1152 Joules of energy. To put this in perspective, it takes about 4200 Joules to heat one litre of water 1°C.

    So, you’ve achieved 45 ha of surface area, separated by a really, really thin layer of glass, and you can now store enough energy to heat a glass of water by one degree!

    Obviously, all the boundaries are being pushed, especially the plate separation, however the tighter those plates, the harder it is to stop leakage between them. I can see how super capacitors would work for short term storage, such as regenerative braking, but I can’t see them storing your solar energy for a rainy day.

    I’d be delighted to be proved wrong, but I reckon chemical reactions are still the way to go for bulk storage of power. That, or old fashioned gravity. Pumping water uphill still has a lot going for it!

    BTW, my figures above may be wrong as they were very quick ‘back of an envelope’ discussion point stuff! I’m happy to be corrected!

  2. Peter Bright

    April 9, 2018 at 12:10 am

  3. Peter Bright

    April 7, 2018 at 10:23 pm

    It’s pleasing to learn from Simon’s post #23 that this technical discussion is useful, so I will proceed with it ..

    Go to https://www.solarchoice.net.au/blog/how-does-maximum-power-tracking-work and scroll down to the plot of module power with module voltage.

    The peak-power point is at the top of the blue curve. If a cloud comes along, that blue curve diminishes in height (less module current) and the peak of the curve shifts to the left because less current from the insolation (sunshine) reduces the module’s terminal voltage also. It’s this turning point that the electronic Maximiser (aka Maximum Peak Power Point Tracker) continuously hunts for.

    The only tracking technique of which I’m aware does this by slightly modulating the load power. The consequence of this modulation is examined and used to amend the mark/space ratio of the Switch Mode Power Supply’s (SMPS) rectangular waveform.

    In my Applied Electronics TAFE course I was slow to catch on to the meaning of “constant current.” It was wholly unfamiliar to me.

    We all know what a constant voltage is because of our familiarity with car batteries and mains power, these being 12 Volts DC and 240 Volts AC. An understanding of constant current is necessary for an insight into the behaviour of solar cells because these are constant current sources of energy, not constant voltage sources. What does this mean?

    A constant voltage source like a car battery supplies whatever current (eg for the starting motor) that the load requires. Ideally its terminal voltage does not fall regardless of how much current is supplied but in practice, due to every battery’s inherent internal resistances, it always will, hence the dimming of the headlights while quite a lot of current goes into your vehicle’s starter motor.

    A constant current source would, ideally, supply a fixed value of current into whatever load is connected to it – be this a battery, a metal rod, a capacitor, a cockroach, a chook feather, a dead short circuit, the USS Enterprise or a piece of string.

    The solar cell can’t do this for all of these because of what it’s made of. It’s basically a large silicon diode exposing its guts to the sun.

    Silicon solar cells of every size have a no-load terminal voltage near 0.60 Volts, and when a solar cell is loaded to its peak power point that voltage will be around 0.5 Volts.

    Most consumer modules have 36 cells connected in series to produce around 21.5 Volts at no load and around 17.5 Volts at peak power. When you connect a battery to it, that terminal voltage voltage instantly drops to the battery voltage. The amount of current going into that battery is linearly dependent on the intensity of the insolation and the area of each solar cell.

    So there’s a mismatch between a battery voltage of 12 Volts and a solar array whose peak power point is at 17.5 Volts. That mismatch is removed by the Maximiser acting as a DC to DC transformer.

    Ideally, if this voltage ratio is 12/17.5 (0.686) the current availability is the inverse of this, namely 17.5/12 which is 1.46 – and so while the voltage goes down the current goes up. Switching losses and various resistance losses guarantee a power conversion benefit of less than 100% and in practice I suspect the power conversion efficiency would not exceed 95%.

    What all this means is that by using a Maximiser you’ll always get all the power that your solar installation is capable of providing, regardless of weather conditions and all temperature effects.

  4. Pete Godfrey

    April 7, 2018 at 10:10 pm

    #23 … Simon, that kickstarter looks like another “wait and see item” to me. I’ve no idea how those skinny leads could supply 400 or 800 amps.
    Also they claim that it can be charged in half an hour from a 5 volt 2 amp power-pack so that would make it equivalent to around a 5 amp hour capacity. I can’t see it happening.

    I have grid power at my place, not for long though.For the last 30+ years at various properties, I have had solar power, and now it grates to be connected to the grid and have bills. So we have organised to have the grid and wires removed. Hopefully the workers will arrive this week to disconnect us.

    We have very modest needs and I have installed a small solar system in readiness for being stand-alone again. I find a feeling of freedom comes from seeing lights around me go out during blackouts while ours still work fine. I guess using little power has its freedoms.

  5. Simon Warriner

    April 7, 2018 at 8:04 pm

    As someone who will at some point in the foreseeable future be interested in battery storage to maximise the return on our panel investment, I find this a most useful discussion.

    So far it seems like “wait and see” is the best strategy. I do like the sound of the super-capacitor idea, and I note that Kincrome is selling a jump start device based on that technology. Not directly related but the tech is getting used commercially.

    https://www.discounttrader.com.au/product/kincrome-kp8001-kickstart-ii-batteryless-jump-starter-charger-800a-kp8001/

  6. Pete Godfrey

    April 7, 2018 at 7:38 pm

    Hi Frank, I agree the faster we can move away from mining scarce resources for our needs the better. The more we learn about natural, renewable and recycled sources, the better.

    Using waste from the cotton industry would be a good way to begin to get away from mining minerals. I am sure that we will see more amazing uses for bio char in the future.

    Peter Bright, I know that Maximisers (basically buck boosters from my understanding) would work but still a regulator would be required after it to stop the panels overcharging the batteries in my case. My panels are connected in two strings that supply 60 volts DC to the MPPT regulators. The advantage I see in this system is that under low light my system begins charging the batteries much sooner that my older PWM regulators would.

    Good luck with your experimentation.

    Cheers,

    Pete

  7. Pete Godfrey

    April 7, 2018 at 7:25 pm

    Hi Frank, it does seem that technology is leaping ahead, all the while we need also to look at natural alternatives. The carbon from Bio sources does sound promising. A way to use cotton waste would be good, too.

    I am sure that as we progress in our understanding of bio products we will find more ways to produce things we need without mining finite resources, lithium being one that seems to have a short lifespan in terms of the deposits available.

    Peter, #18 … the advantage I see in practical terms of MPPT controller is that my panels are connected in series to produce 60 volts DC which allows my system to begin charging the batteries under cloudier conditions and earlier in the morning that would be possible with 12 volt regulators as I used in the past.

    As you say, solar panels are getting cheaper all the time/ My MPPT controllers have increased the charging time for my system by quite a lot. Using a Maximiser would probably work too, but I have not seen them available in high current models with regulation built in.

  8. Frank Strie, Terra-Preta Developments

    April 7, 2018 at 3:24 pm

    Hi Pete and Peter,

    This is possibly not just something for renewable energy and power “nerds”. Having been involved now for some 11 years on this topic of black carbon production and uses etc. here another related link from late 2017: https://www.tandfonline.com/doi/full/10.1080/21663831.2016.1250834

    [i]4. Summary and perspective

    Supercapacitors and lithium-based batteries have demonstrated huge potential to meet the increasing energy demand for rapidly changing portable electronics and electric vehicle markets that require large energy storage and/or fast power delivery. Unfortunately, supercapacitors suffer from low energy density, while lithium–sulfur batteries undergo poor sulfur utilization and deteriorated cyclic properties. Materials design is the key to advance these energy storage devices. Future breakthroughs lie in the development of advanced electrode materials with controlled morphologies, enhanced material properties and optimized functionalities.

    It has been recognized that porous carbons with high surface areas, rich porosity and modified surface chemistry are essential for further boosting electrochemical properties. To date, various carbon materials, including ACs, porous carbons, carbon fibers and nanostructured carbons (graphene, CNT and fullerene), have been widely used in constructing supercapacitors and lithium–sulfur batteries. Unfortunately, most of these carbon materials are often derived from nonrenewable resources under harsh environments and at high cost. In this context, naturally abundant biomass resources with intriguing microstructures are unique with the potential to change conventional energy storage design concepts and open up unprecedented opportunities for developing new high-performance supercapacitors and lithium–sulfur batteries.

    To date, various porous carbon materials have been derived from natural, renewable biomass materials. The specific surface area, pore size distribution, porosity, morphology and even surface chemistry of the biomass-derived carbon materials have been tuned and tailored by different activation methods with different activation agents. The biomass precursors often inherit the porous architecture from the pristine natural materials. One of the best examples is the activated carbon fibers from cotton. The activated cotton fibers are flexible and can serve as a flexible backbone for constructing wearable energy storage devices. Biomass-derived carbons are effective in improving supercapacitors’ energy density and in blocking the dissolution of reaction intermediates in lithium–sulfur batteries. In addition, biomass-derived carbons provide scaffolds for depositing active materials such as metal oxides for supercapacitors, and for hosting sulfur in lithium–sulfur batteries to manipulate the ‘shuttle effects’ of polysulfides and improve the utilization of sulfur.

    Although many efforts have been made to convert biomasses into ACs, the effects of pore size, surface area and surface chemistry on the electrochemical performance of biomass-derived energy storage devices are still, to a large extent, unknown. On the other hand, it is difficult to quantify sustainability from the aspects such as precursors, processing procedures (chemical reagents, processing steps, energy consuming), CO2 emissions, harmful releases and product cycling. Clearly, using biomasses is definitely the right track towards making renewable carbon materials for future energy storage devices. Future thrusts should be devoted to fundamental studies and device configuration optimization with the goal to achieve a high level of sustainability. This requires the cross-cutting collaboration between materials scientists, environmental scientists, chemists, physicist, economists and social scientists. We hope that this review provides inspirations towards developing novel renewable carbon materials for next-generation energy storage devices.

    Acknowledgements

    The authors thank the staff members at the University of Virginia NMCF for electron microscopy technical support.[/i]

    With best regards,

    Frank

  9. Ted Mead

    April 7, 2018 at 2:46 pm

    #16 … Thanks Peter, for keeping the discussion going.

    Beyond a few audacious claims, there remains some things about how this super capacitor model actually operates, particularly the use of its voltage.

    Like Pete, I won’t be replacing my lead-acid batteries whilst they are still fully functional.

    I still believe there is a lot of scope for graphene/carbon capacitors, and time will tell.

    If you look at the battery testing link in the article, it’s obvious that Lithium will be around for a while, but inevitably there will be a market demand for energy storage that is more environmentally sensitive, and will take less energy to produce.

    I think in the next decade or so we will see some amazing energy products appear.

  10. Peter Bright

    April 7, 2018 at 1:24 am

    Thankyou for your response at #17, Pete.

    I suspect that the subject battery packs contain nothing more than a combination of LTO (lithium titanate) cells, perhaps wired in parallel with genuine supercapacitors to secure the best of both worlds and the terrific selling points that have somewhat mesmerised us – not all of which I believe will be confirmed with time.

    I very much doubt if these packs contain any power processing devices as these would be the responsibility of the purchaser depending on just what he wants to do with his newfound energy.

    I Googled Ultra Capacitors. There’s lots of information there like this [i]”Because an ultracapacitor stores energy in an electric field, rather than in a chemical reaction, it can survive hundreds of thousands more charge and discharge cycles than a battery can. A more thorough answer, however, looks at how ultracapacitors compare to capacitors and batteries.”[/i]

    You have referred to ‘Maximum Power Point Tracking regulators’ as a big improvement over PWM regulators, however my own tentative designs of Maximiser circuitry use PWM because of its efficiency over linear regulators.

    Because the insertion of a Maximiser itself incurs SMPS losses, the power boost potential of this device is reduced in practice, but it’s likely there would be a net gain even so. With the falling price of solar modules I suspect that most buyers simply buy more modules these days, and the same reasoning apparently explains the small demand for solar trackers.

  11. Pete Godfrey

    April 6, 2018 at 11:26 pm

    #16 … Peter, thanks for your comments and information. It does appear that there is more in that box than meets the eye.

    I believe that you are right in concluding the they must be using DC to DC converters in there to keep the voltage up to the 48 volts quoted, or that as you say they are using a mix of batteries and capacitors.

    I was very interested when Ultra Capacitors were first developed but they seemed to fizzle out. There weren’t many practical applications for them.

    For now I will stick to my Lead Acid Batteries that are performing well even though they are over 15 years old. Weight is not a problem they just sit on a board in a box.

    Sometimes it is best to keep it simple, although I must say that Maximum Power Point Tracking regulators are a big improvement over Pulse Width Mode regulators, and over simple On-off regulators too.

    So the answer is Yes, your input was valuable and it is good to have a technological discussion from time to time to keep the memory working.

  12. Peter Bright

    April 6, 2018 at 9:42 pm

    Ted and Pete, have the comments in this thread enlightened or confused?

    I’d welcome your interim or final conclusions.

  13. Russell

    April 6, 2018 at 12:41 pm

    Re #2 … “Inevitably, that’s the ‘nature’ of things, but who will it benefit?”

    Those who bother to do anything about the planet’s energy and global warming problems will benefit. This excludes those who choose to do nothing about it, but forever whinge and leach off others, like you.

  14. Peter Bright

    April 5, 2018 at 10:24 pm

    At http://arvio.com.au/supercapacitor-brochure we are presented with a technical data sheet on the Sirius Storage Module rated at 3.55 kWh.

    The nominal terminal voltage is 48 Volts. This figure alone has the characteristics of a battery, not a capacitor.

    A capacitor’s voltage may be any value depending on its state of charge. Place a constant current drain on a capacitor and its terminal voltage will fall linearly with time. This does not happen with a battery whose terminal voltage stays relatively constant.

    At http://www.capacitorguide.com/supercapacitor/ there’s this ..

    [i]”Supercapacitors come with some disadvantages as well. One disadvantage is a relatively low specific energy. The specific energy is a measure of total amount of energy stored in the device divided by its weight. While Li-ion batteries commonly used in cell phones have a specific energy of 100-200 Wh/kg, supercapacitors may only store typically 5 Wh/kg. This means that a supercapacitor that has the same capacity (not capacitance) as a regular battery would weigh up to 40 times as much. The specific energy is not to be confused with the specific power, which is a measure of maximum output power of a device per weight.

    “Another disadvantage is a linear discharge voltage. For example, a battery rated at 2.7V, when at 50% charge would still output a voltage close to 2.7V, while a supercapacitor rated at 2.7V at 50% charge would output exactly half of its maximum charge voltage – 1.35V. This means that the output voltage would fall below the minimal operating voltage of the device running on a supercapacitor, for example a cellphone, and the device would have to shut down before using all the charge in the capacitor. A solution to this problem is using DC-DC converters. This approach introduces new difficulties, such as efficiency and power noise.

    “Cost is the third major disadvantage of currently available supercapacitors. The cost per Wh of a supercapacitor is more than 20 times higher than that of Li-ion batteries. However, cost can be reduced through new technologies and mass production of supercapacitor batteries.

    “Low specific energy, linear discharge voltage and high cost are the main reasons preventing supercapacitors from replacing batteries in most applications.”[/i]

  15. Peter Bright

    April 5, 2018 at 8:31 pm

    Pete, I’m grateful for your incisive comments at #11, your first paragraph in particular making perfect sense to me at first reading.

    I know nothing about the electric motors used to propel electric vehicles, but if they are series wound motors with an electrically supplied magnetic field, or a permanent magnet field, I’d expect the resistance of the armature winding to remain constant.

    This means, given an electrical system wherein the operating voltage is relatively fixed (eg 48 Volts) the motor acting as a generator during regenerative braking [i]cannot[/i] provide a battery charging current greater than that which it is designed to handle when it starts, that is, when the accelerator is first pressed while the vehicle is stationary. This point provides maximum torque just when you need it most. This is an outstanding asset.

    If my reasoning is correct then a supercapacitor buffer is not needed because the “huge currents” that you mention cannot be greater that the start-up current that the system is designed for. Even so, I feel the addition of a supercapacitor, as you outlined so well, would be beneficial.

    Now, looking at Frank’s post at #10 I confess to total ignorance. That’s one helluva complex technical paper at the link he gave.

    But browsing through it I spotted this … [i]”Supercapacitor electrodes from biochar materials showed potential of about 1.3 V”[/i] and a relatively fixed voltage is a characteristic of batteries.

    So what are these wonderful supercapacitors? Are they batteries, or are they capacitors?

    Then I found this equation in Frank’s article ..

    C = (2.I.t) / m. V and for simplicity I’ve reduced the 2/m to the constant, k, a dependent variable.

    Simplifying this further, we now have C.V = I.t which is the same fundamental equation I mentioned in post #9.

    This means that a supercapacitor is an extremely efficient capacitor.

    Nowadays with power MOSFETs, power processors using SMPS (Switched-Mode Power Supply) technology are extremely efficient and can be designed to produce whatever voltage is needed from whatever power source is available.

    Because MOSFETs can be operated at very high frequencies the magnetic core can can be very small. It’s probably not common knowledge that the many varieties of power banks with USB sockets
    have these wired as boost converters to up the lithium cell voltage of 3.7 to the 5.0 Volts at the outlet socket.

  16. Carol Rea

    April 5, 2018 at 7:22 pm

    Just to add into the mix from the proponent …

    John Thirgood is a pretty credible renewable energy authority in Tasmania. A few weeks back on ABC Weekend he and Chris Wiseby talked to Paul Wilson of Arvio. He explained the technology in plain English and also seemed very credible. They already have installers around the country and 200 already sold in VIC.

    Over to you fellas…from 6:43 to 14:43 http://www.abc.net.au/radio/hobart/programs/statewideweekends/solar/9558896

  17. Pete Godfrey

    April 5, 2018 at 7:08 pm

    #9 Thanks for the explanation, Peter.

    The reason that capacitors were suggested for regenerative braking on electric cars was that huge currents would be produced during braking, and that the batteries having a higher resistance would not take the charge or act as a load as well as very low ESR capacitors.

    I can see your argument in regards to the discharge voltage of a capacitor bank. It would mean that during light loads all would be well but if I used my inverter to run power tools or heavy loads for a short while the capacitor bank voltage would drop considerably and no longer be of much use. It appears that voltage regulation would be a problem.

  18. Frank Strie, Terra-Preta Developments

    April 5, 2018 at 6:31 pm

    Hi Pete and all,
    Who would have thought that TASWATER’s Management Team may eventually show some interest in the wide ranging topic of Biochar, Filtrationchar, CoCompostingChar, Constructionchar and say specialised Designerchars???
    Time will tell (if ever) when that happens, meanwhile our global knowledge exchange network, the IBI = International Biochar Initiative is moving from place to place, from Kathmandu in Nepal 2016, then Stockholm 2018 and soon to explore the south of Vienna Austria in June this year.

    I am not trying to confuse the topic here, just wish to provide some links to credible sources of researchers and practicing Biochar producers and users for interested readers to follow up:
    Properties and Beneficial Uses of (Bio)Chars,…
    http://www.mdpi.com/2079-9276/7/1/20/pdf
    by A Callegari – ‎2018

    …” 4.9. (Bio)char in Fuel Cell Systems
    The direct conversion of molten, carbonaceous solid fuel into electricity, without the need of pre-conversion into gaseous form by direct carbon fuel cell(DCFC)was recently achieved[65]. Results showed the feasibility of using (bio)char as a low-cost, renewable fuel for DCFCs notwithstanding its relatively low carbon and high ash contents, achieving fuel cell power density of about 60–70% compared to coal-based fuel cells. In a comparison of carbon fuels for DCFCs (commercial graphite, carbon black, two types of commercial coal, five biochar types) on cell performance, commercially available (bio)char achieved the second highest generation (64.2 mA/cm2) and power densities (32.8 mW/cm2) [66]. (Bio)char has also been tested as a low-cost substitute anode material in microbial fuel cells (MFCs). This technology is capable of simultaneously removing organic matter from wastewater and soil, with direct generation of electricity [67,68], that can be used for other environmental purposes, such as groundwater nitrates decontamination [69,70]. MFC electrode materials are normally granules of graphite or activated carbon, which cost, on the average, from $500 to $2500 per ton, making their construction cost prohibitive at the large scale. (Bio)char was shown to be an alternative, promising material for MFC construction. By using new wood-based biochar for electrodes, cost and power outputoftestedsystemswerecomparabletothosemadewithactivatedcarbonandgraphiteelectrodes. Power output of biochar systems (532–457 mW/m2) was slightly lower than that of activated carbon (674 mW/m2) and graphite (566 mW/m2) systems, at a specific cost f material that was about 90% lower than the others (biochar $17–$35/W, activated carbon $402/W, graphite $392/W) [71]. Finally, PCM was also used as catalyst in MFCs with a carbon cloth air cathode and char catalytic layer coating on both sides of the wet-proofed membrane. The catalytic layer made of sewage-sludge-derived PCM was compared with a huge ly more expensive Pt/Clayer. Power density of the char – coated cathode reached 500mW/m2, comparable to that of Pt/C-coated cathode. This showed that sewage sludge char was active in catalyzing redox reactions in MFCs, and could become an alternative to more expensive Pt catalysts, with even better stability than the latter [72].

    4.10. (Bio)char-Based Supercapacitors

    Supercapacitors are energy storage devices indispensable to store energy from renewable sources, thanks to high-power densities, long lifecycle, and quick charge/discharge capabilities. They can store 10 to 100 times more energy per unit volume than other capacitor types, and can accept and deliver charge much faster than batteries, tolerating many more charge/discharge cycles than rechargeable batteries. They can be used as uninterruptible power sources in electric vehicles like
    Resources 2018, 7, 20 17 of 22
    cars, buses, trains, and elevators, and can be used for regenerative braking, short-term energy storage, or burst-mode power delivery. The electrodes’ microstructure of these devices has a great influence on their performance. The preferred raw materials for making supercapacitors is carbon material with high specific surface area and porous structure, due to its wide availability, relatively low cost, and environmental impacts. Recently, biochar from different biomass feedstocks (paper cardboard and woody biomass) was used for supercapacitor fabrication, indicating that its use of biochar is promising thanks to low cost and satisfactory performance. Supercapacitor electrodes from biochar materials showed potential of about 1.3 V and fast charging–discharging behavior with gravimetric capacitance of about 14 F/g, that could be increased by activating the biochar with nitric acid to115 F/g [72].

  19. Peter Bright

    April 5, 2018 at 5:54 pm

    Pete, you can be sure of my capacitor charge explanation at #5 above, just as I am sure that your arithmetic at #8 is precise.

    I perceive no need for a standby capacitor bank to be charged during a vehicle’s regenerative braking episodes when the energy provided by the vehicle’s momentum can be dumped straight into the main battery itself.

    There is another equation I’d like you to consider, and it’s this: At #5 I’ve shown that Q = I.t but it’s handy to know that Q = C.V also.

    This means that I.t = C.V and rearranging this yields V = I.t / C which means that the Voltage across a capacitor is directly proportion to the time a constant current goes into it during charging, or is extracted from it during discharge.

    Thus while a capacitor is discharged with a constant current its voltage falls linearly. Of course if the load varies then the voltage during discharge will vary accordingly.

    An electric vehicle does [i]not[/i] want this. It wants a fixed source of power provided by a stable voltage across the terminals of its energy source, and ideally, for most us, umpteen zillion coulombs on tap.

    The solution is to put all available energy into the battery because its voltage will remain fairly constant at 48 Volts, or thereabouts, whether it’s being charged or discharged.

    I can tell you Pete, that battery charging under regulation is an engineering field of challenge in itself, the worst variable being temperature, and comprehensive electronic control circuitry is necessary to get it right.

    Charging lithium cells is very finicky and is best left to control circuitry monitoring battery terminal voltage accurately to +- 0.05 Volts, and ideally, the temperature of the battery, too.

    Incidentally Pete, and just as a matter of general interest, a battery is defined as a collection of cells permanently wired in series, or in parallel, or any combination of both. When our parents bought torch batteries for torches or radios or whatever, the correct term should have been cells, and it still is.

  20. Pete Godfrey

    April 5, 2018 at 4:20 pm

    Peter Bright, I am not so sure of your capacitor charge argument.

    Lets say that my solar panels put in 100 amps over a time of 8 hours then that would mean that a capacitor bank would be charged up with 2.88 Mega Coulombs. This would be the equivalent of 800 ampere hours. Pretty useful in my world where I live on solar power and have a 600 ampere hour battery bank.

    Ultra and Super Capacitors have been around for a while now. There was talk of using them in conjunction with batteries in electric cars. The idea was that the capacitors would be charged during regenerative braking and used as a dump to charge the batteries when needed or to supply large current loads.

    A picture of a Lithium battery in a blue plastic shrink cover doesn’t prove much.

  21. Peter Bright

    April 5, 2018 at 4:09 pm

    Ted, I can sense your eagerness to believe in these “supercapacitors” but I feel you’ll be let down sooner rather than later.

    I suspect these “supercapacitors” are not capacitors at all, but batteries made of many cells.

    Have a look at this forum ..

    https://www.eevblog.com/forum/renewable-energy/supercapacitor-energy-storage-and-energy-server-from-kilowatt-labs/

    .. and then consider the two pictures here ..

    http://www.maxwell.com/products/ultracapacitors/48v-modules

    You have mentioned Trump and Abbott. These two modern day Neanderthals are representative of most
    drongos of the conservative or Liberal mindset.

    This is because they know nothing about science or engineering. They are ignorant.

    Well Ted, I’ve just checked what the word “drongo” means.

    [i]”Australian slang: A “no-hoper” or fool. Derives from a racehorse of that name in the 1920’s that never won a race out of 37 starts.[/i]

    Perhaps I’ve been too harsh in categorising the two drongos mentioned above as drongos.

    But it’s near enough.

  22. Ted Mead

    April 5, 2018 at 3:15 pm

    #5 … But this is an Australian based company innovation with the components built in Singapore – all aimed at the Australian market.

    We know Trump is going full bore into disrupting the USA renewables industry, but I find it difficult to believe his operations are active here, unless he has Abbott and his disciples out there in tandem.

    We know Tony Abbott and his cronies are yet making another attack on renewable energy, calling for the Federal Government’s National Energy Guarantee (NEG) to ditch renewables and stump up the cash for a $4 billion coal-fired power station. –

    There was an article in the Australian on April 2nd regarding this.

    So anything is possible.

  23. Peter Bright

    April 5, 2018 at 2:29 pm

    Ted, I can understand your disappointment that the “supercapacitors” we are talking about might not exist. I shall be bold and say they don’t.

    A capacitor is a relatively simple static device for storing electrical energy. In its simplest form two parallel metal plates are separated by an insulator. The electronics industry worldwide would not exist without them, large and small, and in your home right now there are probably hundreds of them.

    When a DC power source is connected to an uncharged capacitor, current will flow into that capacitor until the voltage across its two terminals reaches the voltage of the power source applied. The energy stored in the capacitor will now be half of the capacitance value multiplied by the square of the voltage across its terminals.

    The energy stored is measured in Joules. The capacitance is in Farads and the voltage is in, well, Volts.

    Mathematically this is W = 0.5 C.V^2 where W stands for Work, the updated term for Energy whose symbol was E, hence Einstein’s famous equation E = m.c^2 should nowadays be W = m.c^2

    The quantity of electrical charge in a capacitor is measured in Coulombs, the symbol being Q. This charge is the product of electrical current and time. The symbol for Current is I which is measured in Amps, and the symbol for time is t, measured in seconds, and so Q = I.t where “product” means multiply and so does the dot.

    To store a lot of energy in a capacitor there must be a huge amount of current available to do the job, or a huge amount of time, or any combination of the two which produces the same value of Q.

    A monstrous amount of charge current in a very small period of time is, in my experience, not possible because of various resistances in the circuit loop setup.

    Summing it up Ted, I believe the information about the “supercapacitors” we are discussing here is false, and is very likely the consequence of even more wilful fraud from the USA.

  24. Ted Mead

    April 5, 2018 at 1:44 pm

    Well Peter – there is always a level of skepticism when a new concept is floated, though I welcome any new innovations.

    Lithium is the best we have at the moment, however I suspect in the next 2-3 decades supplies may become a challenge, whereas carbon filled capacitors may take over that role.

    Furthermore it takes a reasonable amount of energy to process lithium into energy storage products, and anything that is energy intensive should be questioned in a long term view unless we have a surplus of renewable energy world-wide.

    The drop in EV batteries called super capacitor replacements are not of the graphene/carbon concept.

  25. Peter Bright

    April 5, 2018 at 1:04 pm

    Ted, with my background in the electronics industry I’m very skeptical of the extreme claims made for these so-called “supercapacitors”.

    A little research produced this at: http://forums.aeva.asn.au/viewtopic.php?p=67082#p67082

    [i]”I’ve finally cracked it! Finally figured out how the scam is done! You were right, Richo and Coulomb! They are lithium titanate (LTO) batteries. Here they are:

    “LTOs are perfectly acceptable lithium-ion cells. But Kilowatt Labs’ and Arvio’s claims of millions of cycles and a 45 year calendar-life are simply false. And their claims of operating at 85 degrees, being non-flammable, and being non-toxic to the point of being compostable, are dangerously false. The patent application is nothing but a smoke-screen.

    “[Note: I’m not claiming that Arvio are scammers, merely that they have been duped by Kilowatt Labs.]”[/i]

  26. TGC

    April 5, 2018 at 1:04 pm

    “Ted believes the world in the next decade will make monumental leaps in design and infrastructures that will transform us out of the old fossil fuel reliance into to a new paradigm that functions on a responsible energy footprint across the globe.”
    Inevitably, that’s the ‘nature’ of things. but who will it benefit?

  27. Doug Nichols

    April 5, 2018 at 12:02 pm

    Sounds good.

    However, there is one pedantic point I can’t help making. The proof is not “in the pudding”. The proof of the pudding is in the eating.

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