Batteries

Published on March 29th, 2016 | by Jake Richardson

114

Calcium-Metal Liquid Battery Demonstrated At MIT

March 29th, 2016 by  

A calcium-metal-based liquid rechargeable battery was recently demonstrated by MIT professor Donald Sadoway and his team of researchers. The battery is intended for grid-scale storage and a long cycle life. Calcium was blended with magnesium to make it usable, and these two elements are often found together during mining operations, so there could be a convenience and lower cost if they can be used effectively to make these kinds of batteries.

mitProfessor Sadoway explained that the greater value to looking into alternative battery formulations is not generating just one new type of chemistry. “The lesson here is to explore different chemistries and be ready for changing market conditions… a whole battery field. He also said that more elements in the periodic table can be examined to potentially make even better batteries.”

The MIT team had to overcome some problems with using calcium: high solubility in molten salts, high reactivity, and high melting temperature. This last problem was solved by mixing calcium with magnesium. This attempt was successful and lowered the melting temperature by about 300 degrees. They also made a new molten salt formulation to decrease solubility by blending calcium chloride with lithium chloride.

MIT liquid metal battery

“Schematic of cell with the negative current collector consisting of a stainless steel rod and Fe–Ni foam and the positive current collector made of mild steel or graphite. The foam contains the negative electrode. Current collectors are electrically isolated by means of an alumina insulator.”

MIT battery

“Charge–discharge voltage time traces of Ca–Mg (20–80 mol%)||Bi, Ca–Mg (90–10 mol%)||Bi, and Ca–Mg (90–10 mol%)||Sb operated at current density 200 mA cm 2 and temperature 650 C. The theoretical capacities of Ca–Mg (20–80 mol%)||Bi, Ca–Mg (90–10 mol%)||Bi, and Ca–Mg (90–10 mol%)||Sb cells were 0.569, 1.33 and 1.08 Ah, respectively. The results of measurements were replicated more than five times, four times and twice, respectively.”

“This paper brings together innovative engineering advances in cell design and component materials within a strategic framework of ‘cost-based discovery’ that is amenable to the massive scale-up required of grid-scale applications,” said Richard Alkire, University of Illinois professor of Chemical and Biomolecular Engineering.

Advantages of this type of battery are the use of earth-abundant materials and that it employs a scalable kind of construction.

The DOE’s Advanced Research Projects Energy (ARPA-E) and the French energy company Total S.A. supported the research.

Clean energy technology such as solar and wind power have become so affordable that more and more people are able to purchase them in some form. Energy storage is growing in parallel, and it is just as exciting, though it doesn’t get much press.

Images by PeterDandy (Creative Commons Attribution-Share Alike 3.0 Unported License); MIT (CC BY 4.0); MIT (CC BY 4.0)


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  • wideEyedPupil

    I think storage gets more press than solar and wind ATM!

    • Bob_Wallace

      More excitement seems to be generated by technologies that are emerging and demonstrating themselves. Wind and solar somewhat “Been there, done that”. They are making remarkable progress but it’s pretty clear to many that they’ve ‘won’.

      Now attention has turned to EVs and storage. The fun seems to be watching disruptive technologies grow to where they grab their first 1% of the market.

  • Elysia Blackhart

    Reading through this article it reminds me of the way electricity moves in a gel electrophoresis machine–very interesting.

  • Jens Stubbe

    If you talk grid scale storage for a 100% renewable system based upon todays renewable technologies then you talk about storage capacity that has to handle days worth of storage.

    The Tesla Giga Factory will provide enough new capacity every year to store about a minute worth of electrons to back up the global grid when it reach full scheduled production capacity.

    The Tesla Giga factory will by that time in just one year produce as much battery capacity as mankind has produced of any kind of battery up to this day.

    The average utilization of an imaginary grid scale battery is never going to be 2000 cycles because you will be scaling the capacity to a worst case scenario with supply demand mismatch, which rarely ever happens. The first few minutes worth of battery capacity will deliver cycle counts as you imagine but as years go by and more battery capacity is grid connected then the average utilization drops.

    The many alternatives to grid scale storage are much more appealing and include:
    1. Renewable capacity over provision (curtails production to match supply)
    2. Renewable capacity factor increase (reduces supply side fluctuation)
    3. Renewable mix planning (reduces supply side fluctuation)
    4. HVDC grid extension (shifts supply/demand geographically)
    5. Smart grid implementation (shifts demand in time)
    6. Power dump technologies regulated by the grid (regulates demand)

    All the alternatives are far more reasonable and less costly than storage and can be applied so you will never need grid scale storage. Storage should be behind the meter or for grid deflection.

    I think the vision of storage was brought about by nuclear and fossil power proponents that time after time draw the intermittent card and claim a modern civilization cannot be based on renewables. In reality it is antiquated and neither economically or ecologically sound.

    • vensonata

      To store 1% or 3.5 days worth of the U.S. grid electricity would require a 40TWh battery. The Tesla gigafactory will produce 35 ghwh per year for cars and 50GWh of battery packs. At 50Gwh per year it would require 800 years to produce a battery to store 1% (40 TWh). Of course that 1% would have at least 1000 cycles and at 30 cycles per year would provide storage for 30% of the U.S. electrical demand for 30 years. Now that is actually a lot…more than is necessary from a chemical battery. However as a single monolithic battery it is ridiculous. We would need 40 gigafactories producing for 20 years to achieve that. Minimum cost 2 trillion dollars. Conclusion: over production of solar and wind is better, and thermal storage and efficiency measures are cheaper.

      • Jamset

        Aquion flow batteries are probably the way to go.

        Does the liquid only contain sodium?

        If so, a lot of factories around the world could make them.

        More efficient solar panels, along with new long-distance HVDC lines to transmit the electricity will help.

        • bink

          Aquion i s not a flow battery, nor is it useful for power applications (short burst of power) it is a long power battery

    • Steven F

      for day night storage of electricity batteries work very well and are hard to beat. however you this doesn’t cover days worth of bad weather or long term reduction in generation due to seasons. now capacity factor, generation mix, HVDC grids can address much if not all of the seasonal or multi day production lows. Batteries however don’t work well to address this issue.

      However you can solve this issue by dumped the occasional overproduction of power into the manufacturing a fuel. Methane and ammonia have a lot of uses are easy to store over very long periods. Both can be used to power a turbine and provide power when renewables cannot. Any fuel not needed for backup water could be sold to companies that use it to make a product.

      • Jens Stubbe

        Among the mature green technologies that will prevail all over the world are net energy producing facilities to clean and recycle municipal waste water. These facilities produce methane and as a byproduct highly concentrated CO2. This CO2 can be turned into methanol with a conversion efficiency at up to 79%.

        The dried sludge from these facilities contains various toxins, micro plastics, metals etc. so is best used as feedstock for HTL (Hydro Thermal Liquifaction) processing that convert biomaterial and plastics into Syngas and Synfuels and a solid fraction with high mineral content usable for mining.

        These processes are all possible to run as cascades when their is surplus energy available and if needed the fuels produced can be converted into electrons. The excess heat can be used internally in the processing or you can sell it off as process heat to other industries.

        Just solving the problems with waste water and waste management will create a market for excess electricity and fuels that can can produce electricity on demand.

        Since these modern waste facilities are actually cost effective relative to older and less advanced facilities they provide both a new power dump option and a new source of electricity on demand production.

        In agriculture the same type of technologies are applicable too and can even do more about GHG because you can prevent Methane pollution from livestock and rotting biomaterials – and agriculture can produce its own fertilizers.

        Handling waste responsible all over USA could definitively suck up excess electrons and provide a lot more than 3.5 days of electricity supply – and the point is that it is cost effective and solve other environmental problems including curbing massive GHG emissions.

        • Bob_Wallace

          How much methane do you think could be pulled from municipal waste?

          Next time you take a dump take a look at what you produce and ask yourself how much recoverable energy there might be.

          Grand Junction, CO has about 60,000 people and make the equivalent of 460 gallons of gasoline per day.

          http://www.theguardian.com/environment/2016/jan/16/colorado-grand-junction-persigo-wastewater-treatment-plant-human-waste-renewable-energy

          That’s 0.008 gallons per person.

          • Jens Stubbe

            I did mention that the municipal waste water facilities just have turned net energy positive. But I also mentioned municipal waste and agricultural waste. Most biomass and municipal waste is burnt or even worse let to rot.

            I can assure you that you can extract factors more methane out of those sources than a 100% renewable grid requires from the lower 48.

            The technologies are there and several companies market them and some like Senergie export biogas, waste management technologies and water treatment technologies to more than 100 countries around the globe. The big problem is that it is still much cheaper to pollute and let society carry the external cost that industries, cities and farmers decides not to handle responsible.

            If you had legislation in place and forced more deployment the cost of biomethane technologies could be reduced and would serve as an excellent renewable backup system that also cleans methane out of the air and recirculate valuable minerals.

          • JonathanMaddox

            How does it clean methane out of the air? Or are you referring simply to avoided emissions?

          • Jens Stubbe

            You literally can clean methane pollution out of air when it comes to animal farming whereas the methane that is prevented from oozing out from city dumps, municipal waste water plants, over fertilized aquatic environments, rotting agricultural biomass etc. are of cause avoided emissions.

    • JonathanMaddox

      I agree with the point you’re making (it will simply never be necessary to store an especially large fraction of gross energy throughput, due to the many superior alternatives to storage) but this isn’t what most people mean when they talk about “grid scale” storage. Storage distributed throughout the grid, both behind the meter and at key infrastructure points, for the purposes of power regulation, smoothing of fluctuations, and even for some demand shifting, is certainly worthwhile.

      Storage doesn’t have to be all in voltaic batteries either. It will be quite a while before batteries overtake pumped hydro in storage or power capacity. Other storage techniques such as thermomechanical ones (q.v. Lightsail, Isentropic, Highview), and probably power-to-gas (http://www.sciencedirect.com/science/article/pii/S0960148115301610), will likely be significant competitors to batteries and pumped hydro in the not so distant future.

      Yes @Bob_Wallace:disqus, I acknowledge that there’s not likely to be that much “excess” power available … but curtailment of intermittent renewable generation does already happen, and will without a doubt happen more if we ever significantly overbuild intermittent generation capacity — and “over provision” is Jens’ first suggestion here.

      • Bob_Wallace

        Excess renewable power now is due to the difficulty in turning off and on coal and nuclear plants. As these plants are replaced with much more dispatchable gas plants that excess will disappear.

        Excess renewable power in the future will likely be sucked up by EV drivers looking for a cheap charge. There may be some excess generation in the spring and fall when demand is typically lower but storing large amounts of liquid fuel for use a few months later might be a problem.

        I suppose we will be freeing up a lot of petroleum/gasoline storage that might be repurposed. But I would expect any renewable liquid fuel we produce would get used up for things like airplanes and agriculture/construction.

        BTW, I just downloaded data for US PuHS and battery storage operational today.

        442,920 kW of chemical (battery) storage. 0.4 GW.
        22,367,700 kW of PuHS. 22.4 GW.

        • Steven F

          “Excess renewable power in the future will likely be sucked up by EV drivers looking for a cheap charge. There may be some excess generation in the spring and fall when demand is typically lower but storing ”

          the california grid on a typical summer day supplys about 40GW of electricity. However during a heat wave the demand can jump substantually. The all time record during a heat wave was 70GW during a week that set multiple demand records about 15 years ago. Any all renewable grid will in the future need the capability to occationally meet unusually large demands.

          Now the 70GW demand spike was unusual. In most years the demand only spikes to 50GW. Improved efficiency will help keep these demand spikes down but they cannot be ellimined with efficiency measures.

          So in the future most of the time a 100%renewable gride will have some excess renewable capacity just sitting there not generating much power most of the time. simply because the power is not needed.

          But it you build facilities to convert air and water to a gas or liquid fuel, that fuel could also be used to keep power on when weather cuts production to less than demand. Such as cloudy days in the winter.

          Storing enoug fuel to get through the winter this is also not much of a problem. After all the strategic petroleum reserve already stores about 3 or 4 months worth of oil demand. And this doesn’t include methane and oil storage industry already has. And most of it is used to store fuel for cars.

          • Jens Stubbe

            Peak power demand is twice of average demand and four times minimum demand.

            The intermittence of solar will go down in the future because for utility scale two axis tracking and the balance between module capacity and inverter capacity will be optimized to enable more seamless grid integration.

            The intermittence of wind is also dropping fast due to rising capacity factors. Some wind farms are well above 50% capacity factor and Cleantechnica has written an article about a NREL study that suggests up to 65% capacity factor.

            I have seen a Danish study that concluded that with current average wind capacity factor in Denmark we would need 10 days of storage but with state of the art wind turbines we would need two days – and thus very likely less with 65% capacity factor.

            Solar, hydro, biogas etc. in the right dosage will remove the storage need provided that the grid infrastructure can handle the massive amounts of electricity that needs to be moved geographically.

        • Jens Stubbe

          Actually even Synfuels are not adequate to make aviation GHG neutral because at the altitude for civilian aviation water vapor is a very powerful GHG. The suggested GHG effect is between a factor 2 and 4 higher, so Synfuels will only reduce the aviation impact with between 50% and 25%.

          My main point is that electricity produced by renewables is very suitable for production of a host of different products that is not going on today in part because those technologies are still being developed and in part because the electricity is too expensive still.

          If you keep the deployment of renewables high then the cost will continue down rapidly and if we solve the billing issue we can develop incentives in the form of cheaper electricity for major consuming technologies that accept grid control with their consumption.

          • Bob_Wallace

            Water vapor is self-limiting. What the air won’t hold will precipitate out.

            We’re seeing higher water vapor content in the atmosphere due to the air being warmer.

          • Jens Stubbe

            Suggested reading http://climatecare.org/wordpress/wp-content/uploads/2013/07/Calculating-the-Environmental-Impact-of-Aviation-Emissions.pdf

            It is 14 pages and there is an interesting Figure 5, which basically explains the physics and the relative importance.

            “The full climate impact of aviation is deemed to be between 2 and 4 times greater than CO2 alone,3 but the exact value is dependent on which parameter is chosen to be measured by the metric.”

          • JonathanMaddox

            This is true of the quantity of water vapour in the lower troposphere, so sea-level water vapour emissions (especially near natural sources of water vapour like oceans, forests etc) have little gross effect on humidity and no global warming impact.

            Aviation, on the other hand, emits water vapour at higher altitudes where humidity is usually much lower, and additionally has a powerful effect on cloud formation in the colder upper atmosphere, which at the altitudes and latitudes most affected, has a net warming effect.

            https://www.newscientist.com/article/dn20304-contrails-warm-the-world-more-than-aviation-emissions/

        • JonathanMaddox

          I think the difficulty of load-following operation by coal and nuclear power stations has been unnecessarily exaggerated (often by their proponents!).

          France frequently reduces nuclear generation as required, and Germany has in recent years used its black-coal-fired power stations effectively as peakers, varying total output by as much as 75% in the space of 12 hours.

          In the USA, with record low gas prices recently, the ill effects of unconventional gas production are emerging and it is not at all clear that the change away from coal has resulted in a net reduction in greenhouse gas emissions in CO₂e terms.

          http://www.thenation.com/article/global-warming-terrifying-new-chemistry/

          Moreover, that shale gas boom and the coal it displaced from electricity generation in the USA helped to cause coal prices to fall, which combined with high prices for conventional gas in Europe, caused significant fuel switching *away* from gas *towards* coal in 2012-2013.

          http://www.carbonbrief.org/uk-emissions-rise-while-most-of-europes-fall

          Fortunately this shift does not appear to have become permanent, with prices for conventional gas in Europe falling again and gas and renewables together displacing coal.

          I think in the long run Jens’ scenario of further replacement of old inflexible coal and nuclear power stations with overbuilt, high-capacity-factor intermittent renewables with significant potential curtailment is more desirable than yours of ongoing expansion of “much more dispatchable gas plants”.

          The most likely scenario is a combination of the two, but it would seem that gigawatt-scale CCGT plants intended for 24/7 “baseload” operation with some load-following ability are no longer attracting significant investment, while smaller, cheaper and less efficient OCGTs and even smaller reciprocating gas engines, intended for infrequent peaking use only, are still bought with some frequency. These smaller peakers certainly aren’t intended to replace coal or nuclear power stations; they’re more of an insurance policy against demand spikes.

          As for the rare week-long seasonal renewable generation deficits of still, overcast days, that’s what mothballed old “baseload” power plants are kept around for. The shiny CCGTs of the past two decades could also end up in that category sooner than expected.

          • Bob_Wallace

            “replacement of old inflexible coal and nuclear power stations with overbuilt, high-capacity-factor intermittent renewables with significant potential curtailment is more desirable than yours of ongoing expansion of “much more dispatchable gas plants”.”

            Absolutely. But until it has been clearly demonstrated to those who run utilities that overbuilding renewables creates a reliable grid I suspect they will continue to add gas capacity. CCNG has a fairly low installed cost, lower than either wind or solar. That makes it an affordable ‘safety net’ for grid operators.

            And, yes, pay some thermal plants capacity fees and fire them up during the rare periods of low wind and solar input. Those few days a year are a tiny part of our larger problem.

            In the US our CCNG plants run only 30% of the time. Our gas turbine (peaker) plants run only 5% of the time. In the future we might need them less than 1% of the time.

      • Jens Stubbe

        Unlike all the technologies you list Synfuels is not necessarily used to return the electrons back into electrons, so rather than constricting the market for wind power and solar cells to the electricity market Synfuels opens a portal into a competitive space totally dominated by Fracking gas, crude oil and coal.

        The perspectives are phenomenal. If solar and wind can perform as in the last five years where they respectively dropped the cost of electricity by 65% and 80% then nearly no wells can keep producing simply because renewable electricity together with excess CO2 becomes the cheapest source for the entire petrochemical industry.

        I think we are living in disruptive times and I have been part of the display industry and have seen disruption unfolding and I have witnessed the despair and denial from executives trapped in companies with products that within less than a decade lost all relevance in the market place.

        I have seen proponents of CRT claiming they will always preserve high quality niche relevance – did not happen – then seen proponents of plasma displays touting their excellence – not enough to survive – then seen the proponents of OLED touting their soon to be dominant technology only to see hopes fade and their once strong Unique Sales Points being annihilated one by one.

        Last week I spoke to two of my former employees that has run a test on live data from wind farms to see if they could have upped the performance with a new set of performance augmenting algorithms they have developed. Their test has proven 1-2% optimization in industry acknowledged simulation tools. They are now going to build a company based upon this idea.

        Two other young engineers I met last year have built a sensor integration system that can collect wind turbine data more accurately and they too could show that their data sets could enhance the performance of wind turbines well above the 1% threshold, which is the tricker point for retrofit decisions.

        Those betting upon slowing renewable penetration and slowing of renewable cost trajectories are living in denial.

        • JonathanMaddox

          If (as Bob insists, probably correctly) electric vehicles make an overwhelming takeover of the light car space in the coming decade or two, oil prices will stay very low and liquid synfuels won’t have much opportunity to compete without strong emissions penalties in addition. I’d like to see this but I don’t expect it soon as a global phenomenon, and it would *have* to be global since oil is so readily transported.

          Synthetic gas (much simpler and probably somewhat cheaper to make than liquid synfuels) is a focus of research in Europe quite specifically as seasonal storage for excess renewable electricity. Of course it doesn’t yet compete with fossil gas either, and in shale-boom USA and other major gas-producing nations it cannot possibly compete, but I think it has a good chance of adoption on a significant scale in Western Europe at least.

          In the truly long run, I’m sure synthetic fuels will *inevitably* replace fossil oil and gas completely, at least for energy-carrying purposes, but not in the required timescale for averting dangerous anthropogenic climate change.

          • Bob_Wallace

            I can see synfuels or biofuel being required for airplanes by European countries and the US at some point in the next 20 years. Probably by some Asian countries as well.

            Once it’s clear that fossil fuels are going away for ground transportation (EVs and electrified rail) there will likely be a lot more attention put on lowering the CO2 created by flying. And oceanic shipping.

          • Jens Stubbe

            The transition away from fossils in shipping can be relatively swift because there are only little more than 100.000 ships in the international shipping fleet and they do not last long in service life simply because the cost of fuel is the dominant cost factor. I expect shipping to be faster to go green than cars. If you analyze the trajectory of energy efficiency improvement in shipping the performance has been phenomenal. The big problem was that they succeeded in using bunker oil, which made the oil companies happy because they could stop selling bunker oil for electricity generation but also created a problem with their huge freed up diesel fraction, which in turn led to the very unfortunate plan that big oil hatched together with EU and the European car industry. EU claimed less CO2 emissions from diesel engines and lowered taxes on diesel cars and on diesel, which has killed hundred thousands Europeans.

            VW’s fraudulent actions later on are a direct result of the shipping industry success with bunker oil.

          • Bob_Wallace

            First we’d need affordable synfuel….

          • Jens Stubbe

            Here are a number of designs that utilize wind as propulsion.

            Use a wind turbine on the deck http://www.marinepropulsors.com/smp/files/downloads/smp11/Paper/FA1-2_Bockmann.pdf

            Use the hull as a sail
            http://www.treehugger.com/clean-technology/innovative-mega-ship-uses-its-own-hull-sail-faster-cut-fuel-use.html

            Use a Flettner rotor
            http://articles.maritimepropulsion.com/article/Collapsible-Flettner-Rotor10401.aspx

            Use modern sails for propulsion
            http://wind-ship.org/en/wind-propulsion-wp-wind-assist-shipping-projects-wasp/

            Use kite propulsion
            http://www.lr.tudelft.nl/fileadmin/Faculteit/LR/Organisatie/Afdelingen_en_Leerstoelen/Afdeling_AEWE/Applied_Sustainable_Science_Engineering_and_Technology/Publications/doc/Ship_propulsion_by_Kites_and_laddermillv2.pdf

            Use wave power proulsion
            http://www.bluebird-electric.net/wave_powered_ships_marine_renewable_energy_research.htm

            Use whale fin like propulsion
            http://www.gizmag.com/whale-tail-wave-foil/38087/ http://www.nap.edu/read/5870/chapter/65#951

            Use solar propulsion
            http://www.motorship.com/news101/engines-and-propulsion/a-step-closer-to-hybrid-power-for-large-ships

            The above can be combined in various ways to enhance the net propulsion energy available.

            As for Synfuels the economic case of cause improve if it can be produced onboard based upon renewables and may well be a byproduct from a shipping fleet that rather than using fossils reverse to produce renewable energy.

          • Bob_Wallace

            Shark jumped….

          • Jens Stubbe

            Not really Bob.

            These technologies range with one exception from demonstrators to full scale installations, so all are TLR 6 or above.

            The exception (the wind hull) is however very simple to verify in CFD software and has also been tested successfully in scale test.

            Norway, Denmark, Holland, Germany and Japan are all major marine nations.

            If you like these technologies are ahead of EV’s because the proportional uptake in the international shipping fleet is larger than the proportion of EV’s out of the entire car fleet.

          • Bob_Wallace

            There are over a million electric cars on the road. How many ships are using these technologies?

            Then let’s return to the topic. We were discussion synfuels for oceanic shipping. You threw in the red herring list rather than addressing the affordability of synfuel.

          • Jens Stubbe

            I think I need to retract that EV vs Shipping statement. The global merchant fleet counts roughly 50.000 ships, which means 40 of them should be fitted with these technologies.

            The wave power propulsion is only used by cruise ships and mainly to dampen the movements of the hull to cater for the passengers.

            In any 100% renewable grid you will need a certain amount of over provision combined with either a strategy where you curtail excess electricity production and/or store excess electricity in batteries or alternatively curtail and/or use the excess to produce Synfuels.

            Synfuels requires more over provision more meaning more wind turbines and more solar modules because Synfuels are poorer at returning electrons than batteries and you obviously have a market outside the electric grid where combustible fuels are in demand.

            For both grid scale batteries and Synfuels to work you have provide excess electricity at a discount.

            We are now in a situation where we can plan.

            Should we scrap all fossil infrastructure over the next decades and gradually replace it with batteries both for storage and propulsion?

            Or should we replace fossils with Synfuels and keep the rest of the usable infrastructure?

            I think we can agree that battery technology is progressing fast but also that fast progression is required to meet demands for sheer volume, cost point and performance.

            I also think we can agree that Synfuels are in every respect superior to crude oil derived fuels and that the required renewable electricity and seawater will not be in short demand so the main is to reach a satisfactory cost point.

            To meet the cost point Synfuels have to go through similar development cycles as batteries are going through at the moment, which means R&D and deployment. Synfuels based upon seawater also entails a number of alternative revenue streams such as fresh water, minerals and metals.

          • Jens Stubbe

            The most EV optimistic feels that 2030 could be a turning point with 50% EV marketshare, which means EV’s will coexist with ICE at least until 2050.

            After that only a minor fleet of ICE cars will be in service for poor people and people who adore vintage cars and people with special needs only ICE cars cater for. Besides that there will be a fleet of trucks, ships and planes also running on fossils.

            The Synfuel optimist (that would be me in this debate) contend that If you keep the current pace towards GHG free energy production then as previous mentioned wind power will singlehandedly produce as much energy as the world did in 2014 by 2031 and just six years later wind power will singlehandedly produce enough energy to deliver electrons to skip the global demand fossils entirely provided we start producing Synfuels.

            If we follow the Synfuel strategy we could by 2040 have seen the last fossil energy exploration say for a very few unwilling countries with fossil resources.

            Clearly Synfuel production is a production on a massive scale but so is the complete value chain needed to build enough EV’s. Bob has mentioned 190 Giga Factories.

            Ps. I do not think you are correct in assessing that methane is a simpler process technology. I base my opinion upon US Navy research and two very pieces of very interesting research that has been published in 2016 pertaining Ruthenium catalyst processes that can convert CO2 with an efficiency of 79% into Methanol. From Methanol the petrochemical industry can build anything.

          • Bob_Wallace

            If EVs reach 50% of new car sales by 2030 I don’t think there will be many ICEVs left on the road by 2050. People with limited incomes are going to prefer an EV for the fuel savings. ICEVs are likely to head to the crusher at a much younger age than will EVs.

            190 GigaFactories sounds like a lot, but remember we’ve got “190 GigaFactories” of ICE factories in operation today. The battery factories will not be additional manufacturing, but replacement manufacturing.

          • Jens Stubbe

            I think I arrived at the same conclusion but the problem that I address is the slowing transition to renewables with the EV strategy relative to Synfuels.

            The battery factories with complete value chains beginning with mining will not be replacement factories after a certain threshold unless new battery chemistries or strong improvement of battery technology change that.

            The one sure thing is that if my projections based upon the historical trends for wind and solar unfold as I suggest then the Synfuel scenario will make a faster and more complete stop to fossils.

            Interestingly EV’s had a decent marketshare before Cadillac invented the self-starter and Synfuel has been in industrial scale in Europe and later on in South Africa albeit based upon coal.

          • Bob_Wallace

            Battery factories would have to be built, mines opened and mineral processing increased.

            Synfuel factories would have to be built.

            Why would one of these ramp ups take longer than the other?

            What’s the best $/mile cost for driving with synfuel based on what could actually be marketed today? It would need to be a drop in replacement for gasoline or diesel.

          • Jens Stubbe

            You are asking the right questions – answering them are a bit more complex. You have to accept that the situation with Synfuels is like pre Tesla for EV’s.

            The big difference is that Synfuels “mines” solar, wind, seawater” and are very tiny plants relative to battery Giga Factories because the produce liquids with high power capacity that can be stored in existing fossil fuel infrastructure.

            Apart from very large quanta of seawater and electricity there is not much going into to the process. What goes out is more diverse because you can produce a huge amount of different minerals and metals as well as fresh water as by products.

            The Synfuels I have seen in research projects with very limited scale is Methane and in so far I believe they just add it to the natural gas system.

            Air Liquide is constructing a Hydrogen production line and a Danish company is building a production line for mass producing Hydrogen. I am not pro hydrogen but the thinking is the same – use the excess electrons.

          • Bob_Wallace

            The infrastructure for both would need to be built. Infrastructure costs are part of cost to drive a mile.

            I take it that you cannot answer the “What’s the best $/mile cost for driving with synfuel based on what could actually be marketed today?” question?

            We know the cost of driving with an EV today.

          • Jens Stubbe

            I find the question misplaced since we are dealing with a strategic challenge. Any technology has to see deployment before it can become cheap.

            Besides it is very complex to calculate the cost associated with driving an EV.

          • Bob_Wallace

            No, you find the question inconvenient.

            The answer is, based on your lack of a forthright reply, there is no synfuel today that is affordable.

            The best one could say is that there might be some day. Affordable synfuel is a hypothetical and in your comments you should make that clear.

  • eveee

    One wonders if they will solve the seal problems that plagued other liquid metal attempts.

    • Bob_Wallace

      Would it be possible to weld the cells shut?

      • eveee

        I don’t know the nature of the problem. The issue is that high temperatures require expansion and contraction and must provide an airtight seal.

        “Ambri’s researchers now face the challenge of scaling the liquid-metal battery up to industrial size. Among other tasks, they must design airtight seals on the cells and create a thermal management system that makes sure the heat given off by charging and discharging is enough to keep the components liquid.”

        Read more at: http://www.energyharvestingjournal.com/articles/5176/new-liquid-metal-batteries-for-improved-energy-storage

        • Bob_Wallace

          I can see a problem sealing a small cell. But move to a much larger cell – say deep freezer sized or whatever can be reasonably transported from factory to site.

          Build the cell as a big metal box. Put the metals inside. Weld the top on. Truck it to the site. Hook it up and start warming it up.

          I would assume that there’s an air space inside the cell to allow expansion. Otherwise the cell wouldn’t be sealed.

          Or perhaps the cells could be very large metal vats inside a heavily insulated building. The trick is to keep the heat from escaping.

          • Steven F

            You need a ceramic seal between the positive and negative terminals of the battery. You cannot weld those.

          • Brian S.

            Don’t forget that you need to keep the two electrodes electrically insulated, and they need external connections. It’s pretty hard to avoid the need for a seal between an insulating ceramic and metal. Not saying it’s unsolvable, just that it’s not trivial.

          • Mike Shurtleff

            I would love to know what Ambri is up to with this. High temp ceramic semiconductor? Arm chair engineering myself. I don’t even know if that’s a viable possibility. Would love to know more.

          • Mike Shurtleff

            Arm chair engineering. Keeping the heat hasn’t been identified as a problem and Ambri has done a lot of testing. Taking their time on seal problem and we haven’t seen a solution yet. Tough problem? Taking them a long time to test properly? Taking their time to make sure they get it right? Who knows. No info.

        • DecksUpMySleeve

          A small ‘Flexible Diaphragm’ Structural “Lung” like those built within Biodomes could keep pressure a constant in the cell. Quite easy to do at that scale.. Just a liquid and pocket which it can shift the pressure into, maybe a ‘Check valve’ if the pressure for some reason needs venting, which could easily be automated at the large scale by something akin to an Arduino pressure monitor. Or a Check Valve opened by a springloaded spit channel the pressure itself operates.

          • Steven F

            Pressure and venting is not really a problem for these batteries. The problem is thermal expansion and contraction cause by electrical heating. Every time the battery is charged or discharged heat is created. When the battery is not charging or discharging the battery cools.

          • DecksUpMySleeve

            Of course there is also the non-fluid expansion as well, key there is making the heat differential drawn out by keeping a relatively sized discharge following a temperature spike. Gradual as possible is the required there, rapid flux will shatter, too quick will warp. A good way to get around this is adjacent/parallel pairing. As one discharges high those beside it do lesser. Levelizing through automated discharge systems.
            Furtherly this is decided by the optimal discharge temperature’s relation to the stability necessary sweetspot, along with this vectors ratio to cost. This cost will in time involve utilization and recycling both the cage and liquid bodies.

        • Steven F

          There are two seals on the battery. One can be welded and i probably not the one causing the problem.

          The second seal separates the positive and negative terminals. It must be made from materials that don’t conduct electricity. Many batteries use plastic or rubber materials. These will not work at 600C. This limits the choice to ceramics and glasses.

          • Bob_Wallace

            How about you create a ceramic plug that is inserted into a recess in the metal box from the inside (think sink plug).

            Weld on some brackets to keep it in place.

            “Caulk” the seam with a metal with a higher melting point than the operating temperature of the battery? Does the caulk have to be flexible to allow for different rates of expansion for the battery box and ceramic plug?

          • Steven F

            “Does the caulk have to be flexible to allow for different rates of expansion for the battery box and ceramic plug?”

            It depends on how much thermal expansion and contraction they are dealing with. If they can keep the temperatures swings inside the battery low then expansion and contraction would be low and low or flexability might work. If the temperature swings are high than a softer seal would be needed.

            The other issue to keep in mind is fatigue. If you apply load to any material repeatable that material will eventually fail. it may last 1 year, 10 years, or 100 years. they can probably make a seal that last 10 year now but I think the market wants more than that. The typical pole mounted transformer will go 30 to 50 years without maintenance. I think utilities would want a battery like that.

            I think in the long run a repairable seal will offer the longest life. now that could mean a ceramic plug with a glass caulk that is simply flame heated to seal the crack when it cracks. If that is done you might also need a port so that internal pressure can be monitored. A seal failure would cause a pressure change. The port could also be used to pump out the air that gets in and then refill the battery with an inert filler gas such as Argon.

            Another option might be to make the battery without a seal. This would involve careful selection of materials to limit corrosion and to use salts and metals that do not react with air very much. Or it might be possible to adding some sort of oxygen, nitrogen, carbon absorber to the inside of the battery.

            Overall I think it is a solvable problem but it may take more time to design and test than most people think.

  • JamesWimberley

    Total are the controlling shareholder of SunPower. They may have more expertise here than meets the eye. What’s more, as an oil major they have the financial muscle to move any promising technology into production. That’s not to say they will. Grid storage is a crowded field.

  • vensonata

    The U.S. Department of energy “Sunshot” goal is $125 per kwh for battery storage. It was set in 2014 when prices were approximately $500 kwh for practical lithium rechargeable. At even 2000 cycles that is about 6 cents kwh levelized cost. That is already entirely reasonable, requires no new technology, and in fact most lithium batteries easily exceed that cycle life. At a modest 10 year lifespan or 3650 cycles the cost per kwh would be 3.5 cents kwh. Who could complain at that price? It appears to be just a matter of mass manufacturing to arrive at this goal. Presently, at large scale we are closing in on $150 kwh now, so it looks like the Sunshot goal will be reached early.

    • bink

      vensonata, I love our friendly debates about energy storage but I want to get serious for a moment. I want you to take seriously the information you put out.

      Unless it says otherwise, any time the government puts out prices for batteries they are talking about battery cells not a total all-in system cost. The total install for a lithium battery system in 2014 was just over a $1,000 kWh ($1,200) and there is plenty of available data to support that figure. And I can tell you a total system was more like $800 – 850 per kWh.

      We are talking stationary grid connected so we are clear. Lets take the Tesla Powerpack at a claimed $250 per kWh (lets be clear the contents are a set of battery modules w/ BEMS)) every other component (inverter, controller PCS) is added by the integrator.

      Lithium is supported by auxiliary HVAC support and other cooling systems that have to be installed along side sometimes within a butler with lighting, etc…all of this increases the permitting and commissioning, testing and installation and construction costs; typically 40% or more. Then you have to include the integrator or developer markup (10-15%).

      So you can see where you are providing erroneous information.

      warmest regards

      • vensonata

        See my reply to Brian S. below. The cost reckoning of batteries is not for the purpose of establishing the final cost per kwh when all other factors are taken into consideration. That is not the intent. The intent is the same as saying the “price per watt” of a PV panel is 45cents. It is merely for comparison purposes with other panels. It does not mention where it is installed whether sunny or cloudy, or the cost of permits, or the inverter costs or racking costs.
        We are putting these costs just as the DOE did. $500 kwh and aiming at $125 kwh. Those are their figures not mine.
        Secondly, you are almost always talking about grid utility batteries. There are other uses which make far milder demands such as residential installations which is what I am primarily interested in. Commercial scale use of the Tesla 100 kwh Powerpack seem to also be used in stores and factories and warehouses, it is much different than grid use. That said, at this point in time far more lithium type batteries seem to be appearing for grid regulation than any other type, such as flow batteries. The engineers and management make those choices and they plainly show their preference.
        As always I am completely neutral on the format. Whatever works and is most economical is the best battery. Vanadium or Lithium, what possible preference could anyone have except “does it work?”

        • bink

          Batteries are not PV panels. Boiling it down into those simplistic terms is not recognizing the fundamental complexity and very different technology platforms. When one talks about pricing for a DC lithium battery cell, it is literally, the battery cell, nothing more.

          A DC redox battery would include the balance of plant and battery management and controller systems, only requiring an inverter to get to AC. There is no apples to apples comparisons here across the technology platforms.

          I am talking C&I as well. Residential is not a mature market as yet with the economics yet to be proven so there are technical and market rule challenges there.

          No credibile battery person is going to tell you that frequency regulation by itself is a sustainable strategy. You need to have the capability to stack benefits. As I told you before lithium is causing issues in the PJM regulation market because the operation range is limited mainly its run time.
          Most if not all of the units participating in that market are providing sub-hourly services but when the grid operator signal set back to zero the grid operator had to manually force the units to run longer.

          They even talked about the need for VRB’s to participate to resolve some of these issues.

          The powerpack is not getting that much play or acceptance after an initial flurry of interest from people who have no clue. Just because you are an engineer or planner means nothing when it comes to understanding battery storage. That comes from my engineer who has 23 years of integrated resource utility planning, building power plants and operational experience

        • eveee

          Vensonata – I agree regarding comparisons and whatever works. did this entire dance with him before. He’s looking for a tender ear. One look at the pictures of tesla power packs and you can see it may not be how he figures. Other utility lithium storage is containerized (40 footer) and needs air conditioning. The metal containers are good for shipping and lousy for heat. Power packs are separate units and I believe have liquid cooling and fans.

          https://c1cleantechnicacom-wpengine.netdna-ssl.com/files/2015/05/Tesla-Powerblocks.jpg

          The layout gives more area for heat transfer.

          http://www.wired.com/wp-content/uploads/2015/04/LW3A1486.jpg

          Orange wires are power, blue, coolant. If there is air conditioning, it has to be in the door. Not much room for that. Idk.

    • Brian S.

      For long-lasting batteries, the discount rate is going to play a large role. Also, don’t forget the balance of plant costs. Presumably, inverter costs can be minimized by colocating the batteries with PV installations, but there are plenty of costs left.

      Also, if your battery is used for daily cycling, the depth of that cycling will vary by day. So you won’t put a full 365 cycles on the battery per year, but somewhat less.

      Here’s a quick table showing the diminishing financial returns to increasing cycle life depending on the number of cycles per year. I assumed a 7% discount rate and 250 cycles per year.

      Cycle life, calendar life (years), total discounted cycles
      1000, 4, 872
      2000, 8, 1531
      3000, 12, 2029
      4000, 16, 2406
      5000, 20, 2690
      10000, 40, 3353

      So if a $125/kWh battery lasts for 5000 cycles, the simple calculation is $0.025/kWh. But if the fully installed price climbs to $200/kWh, and you use 250 cycles per year at a 7% discount rate, the levelized capital cost climbs to $0.074/kWh.

      Just some factors to consider.

      • vensonata

        The calculations for batteries are much better restricted to simply cycle life, efficiency round trip, and cost per kwh. All other factors are variable and smokescreen a simple comparison. Don’t bring in inverter costs, installation, interest rates etc. They may play a role but they distract from an even comparison. Inverter prices may be included in the cost of the PV install, permit costs are wildly different in different states and countries.
        Consider how PV panels are given a Price per watt. It has nothing to do with the inverter, the install, the cabling etc. This is how we apply the same standard.

        • Brian S.

          That’s fine, but also remember that even though PV panels are priced at $0.65/W or so and last for 25+ years, you can’t generate electricity for $0.65/Wp / (2 kWh/Wp/year * 25 years) = $0.013/kWh. So yes, for quick comparisons, it makes sense to stick to cost per kWh, cycle life, and efficiency. But you can’t say, “[$0.035/kWh] Who could complain at that price?” because the real price will be considerably higher.

          Remember, there was a time when people were obsessed with the $1.00/W module price goal, at which point “grid-parity” would be reached. It was a good, easy-to-understand goal, but in the end, we needed to go a lot further.

          We’re probably thinking about different things here. $125/kWh might be cheap enough for PV self-consumption in places like Australia or California. However, I want to see utilities using solar plus storage instead of combined cycle natural gas. Not grid regulation, but bulk energy storage. I think that will require prices well below $125/kWh. It’s probably also way too early to think about, because you can’t store excess solar energy until you actually have excess solar energy.

          • bink

            for solar plus storage to replace a CCNG it would have to provide the same service capabilities attributes to justify it.

          • eveee

            An inverter is not part of the price of a battery in a renewable system. A solar installation already requires an inverter. Otherwise we could say a solar system requires an inverter and solar cell costs must include it. No. Just calculate the costs independently and then show them combined so the details aren’t hidden.

            One other thing. Paybacks are considered based on displaced electricity costs. Yet grid electricity costs also rise. Calculation and comparison without this consideration skews the numbers in favor of grid electricity. If grid electricity costs grow at about interest rate levels, they negate the alternative interest cost.

          • Brian S.

            “Presumably, inverter costs can be minimized by colocating the batteries with PV installations.” Minimized, not eliminated, because a storage inverter probably costs a bit more than a PV only inverter.

            You are right that future changes in electricity rates are important when calculating returns. However, I’d be careful in assuming large increases in electricity prices. Renewable energy and storage are both getting cheaper with time. Fossil fuel demand will hopefully be weak. Why should electricity prices rise?

          • bink

            Brian S i tend to agree with you. these comments are slicing the same thing a different way and expect the result to change. cost effectiveness is the biggest consideration. on the one hand they only want you to consider the battery cell cost yet they quote a kWh price as though that is the cost of storing electricity

          • Bob_Wallace

            Is there an accepted number one can use to compare storage technologies?

            Something like “If this system was used on a utility grid the cost to store a kWh for one day would be X cents. To store for five days would be Y cents”?

            If not then, in your opinion, could the industry develop a simple metric that would be easily understood?

          • bink

            The cost to store does not change based on the number of days. Cycling or utilization would be more accurate measure for people not in the business. Storage is a service and not a commidity pricing based on energy kWh costs so much. If you strictly based it on kWh pricing you are not looking at the correct value proposition as it pertains to the utility nor commercial/ industrial customer

          • Bob_Wallace

            Yes, the cost of storage does change depending on whether the storage is being cycled daily or only a few times a year when dealing with extended periods of low wind/solar input.

            The issue that concerns many of us is whether we can afford to cover those infrequent events with storage or do we need to look to dispatcable generation.

            I think what you are saying is 1) that there is no easy to use/comprehend metric and 2) you can’t dream up one.

          • bink

            not trying to dream one up. you are using per kWh commodity unit pricing and i am not. the energy service is detached from kWh unit pricing of energy. the cost is fixed when installed it is the utilization that is at issue here so you are correct in that regard but that has nothing to do with if I am sitting idle for a couple of days.

            i can sit idle and still get paid in the ISO’s with capacity markets, greater utilization increases ROI and vice versa if that is what you mean

            And you also make my point about what technology you choose. operational range is key to capability to stack multiples of benefits.

          • bink

            storage is service based. think of it as a natural gas unit. only the power plant is the storage and the fuel is the solar fuel produced from the PV. Solar energy is sold as a commodity w/ associated market pricing. Storage is not sold to a utility in kWh unit pricing. The value proposition is different. that is why total install is more important than any one component cost, no different than a CCGT.

            For instance regulation which is a balancing service is a payment that solar will never realize. A solar array cannot provide that balancing service but it generates the energy.

            A regulation service payment is based on how many MW’s of energy or power, the CCGT or storage unit can move, how far (mileage) and how quickly, not the energy per kWh unit it is discharging.

            A capacity payment will allow you to get paid for the available capacity not the energy contained within. If you where to have a storage + solar configuration then you could get paid for generation and capacity in some markets.

            hopefully you see the difference

          • Bob_Wallace

            Sorry I asked. I should have known better.

          • eveee

            A discussion of how Lazards used stacking to better evaluate storage benefits is due here. Battery storage does several functions well, not just one. Those benefits are worth more than average wholesale.
            It’s best not to compare battery storage against one form of generation such as CCNG. The characteristics and capabilities are too different.

          • bink

            Lazards model is inaccurate, outdated and doesn’t have certain default measure. Their have been many analysts and companies who have pushed back on using LCOE as a true cost of a storage system. Even they, themselves have admitted there was modeling work to be done on that issue.

            Yes battery storage does several functions very well but the availability of all of those functions does not exist in a single installation for all battery types.

            Solid State battery power and energy attributes are packaged together (coupled) they can not be separated at a cell or system level. Once the type of battery chemical is selected the compatible electrode is determined for manufacturing. The thickness of the electrode determines whether the battery will provide energy or power services. It is well known and documented that lithium battery functions are limited either a power or energy application in a single install, but not both. So opportunity for stacking benefits is limited to one of those (2) categories. There may be further limitations to stacking even within a category depending on customer, service priorities.

          • Brian S.

            “It is well known and documented that lithium battery functions are limited either a power or energy application in a single install, but not both.”

            Stop saying that. It’s not true. The decoupling benefit of flow batteries is just a cost benefit. The marginal cost to scale up capacity is small because you only scale the electrolyte and the tank. That’s it. An 8 MWh, 1 MW lithium ion battery can stack benefits just the same as an 8 MWh, 1 MW vanadium flow battery.

          • bink

            are you really looking to stand behind that statement. The decoupling is a cost and revenue benefit. The department of energy has documented the operational limitation of the lithium battery. For a real world example lets take the lithium redox battery resources that have been deployed in the PJM. they all participate in the regulation markets but none in the reserve capacity markets. Solar city & Tesla installation in Hawaii. What service are they performing ? load shifting and that is it. Why would they not take advantage of providing regulation services in the same installation because they cant? Its a one trick pony

          • Brian S.

            Yes, I will stand behind that statement. You are mixing up market constraints with technical constraints.First, is storage allowed to participate in PJM’s reserve capacity market? Second is the price high enough to cover the cost? I don’t know the answer to the first question, but the second question is a guaranteed no.

            In Hawaii, is there even a frequency regulation market to bid into? And how do you know the batteries won’t provide ancillary services?

          • bink

            yes it is allowed to participate in the capacity markets. It doesn matter whether the price is high enough. No one market service is high enough to be sustainable. You have heard of stacking benefits right? and you are making my point.

            You really are clueless. You dont need a ISO type market to get paid for regulation services. In a vertical market its called resource adequacy which is another revenue opportunity so why would you not capture it if you had the capability but like I stated that is common knowledge solid state batteries have coupled power and energy attributes. Maybe if you had listed to the last weeks webinars from CESA and DOE you would have heard it for yourself.

            As a matter of fact the PJM had to cap the fast response regulation market because the lithium resources had limited run-time in following the signals. so they have limited that market for batteries to 5 hours per day while they figure out new rules

            duke energy is trying to put some hybrid configuration together (Capacitor and Aquion battery to smooth a solar array and load shift. they have used lithium batteries before yet they are during a hybrid to try and perform a power and energy service for the install

          • bink

            I chose CCNG (GT) as a comparison because it provides a wider range of services than the other FF types and is used to provide baseload and ancillary services. It would be difficult (no) impossible for a solid state lithium battery to provide the grid services of a Aeroderivative GT with out a more expensive and complex HESS configuration. Aeroderivative are used to provide peak services and system reliability; frequency response and voltage support.

            CCGT’s don’t provide second to second regulation

          • eveee

            There are people that disagree and then there are disagreeable people.

          • wideEyedPupil

            or as a freind of mine says, LCOE is a very poor metric for storage. Consider one case senario where you are buying power for near or less than zero dollars (as occurs on some energy markets overnight) and selling for $1000s per kWhr which happens in some markets at peak. that’s good arbitrage and you can’t even make an LOCE calculation without a fixed energy cost assumption.

          • eveee

            Why should electricity prices rise? Because some utilities have stranded FF assets and rising fuel costs.

          • Brian S.

            Well, we’ll see. But I think slack demand will keep prices relatively low, though maybe higher than they are today.

            Of course in 2008, I thought oil prices would be forever high. I was wrong. Now I think they’ll stay relatively low. Did I learn my lesson, or am I just making the same mistake again?

          • eveee

            I wish I knew. Inflation causes prices to rise even if nothing else happens. But we are in a recessionary time where prices can fall.
            I don’t know why I didn’t think of it, but when a commodity becomes passé, and underutilized, the providers will make it as cheap as possible in an effort to keep it going. We are starting to see the with oil. As pointed out, there are volume effects to cost, and once a competitor loses market share, it gets dicey for them. Witness Saudia Arabias bid for market share.
            In some ways, there is no way to make an exact comparison. I think oil prices will stay depressed for a while and slowly rise as extra supplies bloated by artificially maintained high prices fall out of the market.
            IMO, we can have all the oil we want at high prices, or smaller amounts at lower prices. But we can’t have both high volume and low prices. The rate of consumption matters here, not just the available supplies. And behind all this, supplies are drying up and new ones are not being found. The amount of conventional oil is dropping. Saudi Arabia won’t be able to pump conventional oil at these prices forever. Even they have to add more exotic means to get it out as more gets pulled out of the earth. All of this adds up to a topsy turvy world where oil prices are bound to be volatile. Competition could change that.

            Hopefully, at some point, we just stop the madness and recognize that we can always have cheap fuel if we use the air as a sewer. Or did we just find out that isn’t true in China?

          • bink

            you can use a DC bus w/ grid tied smart inverter to accomplish sharing inverter on battery side. There are a couple of challenges though, first, the solar production would take a haircut if you don’t utilize a converter or optimizer w/ a MPPT, so I don’t know how much you are actually reducing component count and costs. Secondly, using the wrong battery technology will limit the services you can offer to smoothing the solar production

    • Jamset

      Is the Sunshot for EVs or grid storage?

      EV batteries can only do 500 cycles, grid storage batteries can do 5000.

      It would be better if the DoE actually buys an LG/Samsung/Powerwall and tests them to see how many cycles can be done.

      • bink

        are you kidding me? there is a process for any battery company that wants to test its battery for a variety of things and get a government report. there are three national labs that will give you the skinny the fact that they haven’t done that tells you everything. If you call them up right now ask them to give you an affirmative on that 5000 cycles that will tell you they cant do that and to call them in 3 years after they have started testing. That is because the jury is still out.

      • Mike Shurtleff

        “EV batteries can only do 500 cycles”
        False.
        Most of EV batteries are lithium and most are in the 1,000s of cycles. Hard to find one less than 2,000 cycles, at 70% or 80% DoD. 3,000 cycles is typical for lithium ferrite batteries. Even some lead acid AGM batteries can cycle over 1,000 times at 30% or 40% DoD (not sure of memory on lead acid DoD).

        • Jamset

          Even the cheapest EV in the world does not use lead acid batteries. The energy density is not high enough.

          The Tesla Model S does not give thousands of cycles. The Powerwall does because it uses a different, much less dense, chemistry.

          • eveee

            Energy density is mostly irrelevant for grid storage. Cost/kwhr/cycle is a dominant metric.

          • Jamset

            We all know that.

          • eveee

            You mean the red line in the curves? Thats for a LiFeP battery. Those are higher power, lower energy density. Is that what you meant?

          • Jamset

            Yes, LiFePo4 cells can do more cycles than highly dense EV lithium batteries.

          • eveee

            LiFeP are lower energy density and higher power cells. Usually that combination results in less cycles under the same conditions. Lower power or C rate usually results in higher cycle life. Look at the curves and you can see that under 100% cycling, the LiFeP cycle life is pretty low.

          • bink

            neither of you know what you are talking about

          • bink

            I call you know what on that

      • eveee

        EV batteries can do more than 500 cycles. Cycle life depends on depth of discharge. It’s very non linear. Operating at 100% depth of discharge is extremely wasteful of battery life. One might double battery life by reducing discharge to 80% for example.
        http://www.ev-power.com.au/IMG/png/Screen_Shot_2014-09-30_at_10.04.55_AM.png

        • Jamset

          The red line here is for grid storage batteries, or slow EVs.

          Tesla car batteries are much higher in energy density than Tesla Powerwall batteries.

  • Marion Meads

    looking at the charge and discharge curves illustrates that predicting the amount of energy remaining or to be filled up based on just voltage would be prone to inaccuracies.

    Although not discussed directly, it is implied that the LIQUID battery to stay liquid meant it is molten. Lowering the temperature by 300 degrees using Mg is a give away clue that the liquid is not the room temperature liquid! Why they didn’t say molten in the first place? Molten means liquid at high temperature…

    • DecksUpMySleeve

      They have mentioned the molten nature in many past press releases of the liquid metal batteries.
      At the large scale in plants with available ‘waste heat'(if you can call any heat which can become power wasteable) can adhere to this.
      On the largest scale I see LM batteries possibly filling the gap, domestically I think Lithium/Silica/Flow/Manganese based batteries more likely in the short term, short of a breakthrough.

      • Steven F

        Every time you charge or discharge a battery some electricity is converted to heat and is lost. This loss or waste heat combined with insulation keeps the battery molten.

        While the high operating temperature of the molten metal battery is a disadvantage. There are several advantages these batteries have.
        1. They can handle very fast charge rates without damage.
        2. They can also discharge very fast without damage.
        3. They can handle 100% depth of discharge without suffering any loss of capacity.
        4. The molten state prevents dendrite formation which can shorts out and kills most other batteries.
        5 Cycling causes no loss of capacity
        6 No long term chemistry or structural changes that often cause capacity loss in other batteries.

        Many of the batteries Ambri has tested have been cycle tested a charging and discharging conditions that will kill any other type of battery within minutes. When was the last time you saw a battery report that hows test results with over 1000 cycles?

        • DecksUpMySleeve

          I’m aware of this, been watching MIT’s liquid batteries some time, they’ve used widely varied chemisties in a trial an error since it’s origin. I’m sure they’ll have applications in the years to come.

        • bink

          sounds like a vanadium redox battery to me, minus the fire hazard, high temperature, extreme weight and complexity.

  • Bob_Wallace

    Ambri has been unable to manufacture cells with their previous chemistry. All this may be is another interesting observation which stays in the lab.

    • Steven F

      The problem Ambri has is not due to chemistry. The batteries must be sealed so that air doesn’t get in. In there previous design the seal was failing .

      Even if ambri cannot make a seal that lasts for 10 years, they could make a repairable seal that could be repaired or replaced in a short period of time.

      • JonathanMaddox

        Or they could put the batteries in a secondarily-sealed inert atmosphere of CO₂ or nitrogen.

  • John Norris

    This thing still runs at 600C! More info at:

    http://phys.org/news/2016-03-chemistries-liquid-batteries.html

    • DecksUpMySleeve

      Nice cycle life and efficiency too, wonder if they’ll ever make it into a factory..

    • JamesWimberley

      Why is that a killer objection for a fixed grid storage battery? The gas temperature inside an ICE can reach 1,500 C. Obviously there are safety and insulation issues, but nothing insoluble.

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