I think we can all agree that the supply of plausible renewable energy sources; i.e., non-fossil energy sources, is effectively inexhaustible. The inventory of such sources comes back to three plausible non-nuclear sources: solar, gravity and geothermal.  Solar includes photovoltaics, wind and waves, just to name three (you need the sun for wind and waves).  Gravity gives us potential energy like hydroelectric and kinetic energy like tides. Geothermal gives us heat to make steam for turbines or to power thermopiles.

Wait a minute.  What about biofuels, biomasses and such?  Well, technically, these are all solar-based in the final analysis.  And sources that use chemical potential energy to generate electricity, such as batteries and fuel cells, are powered by the three energy sources listed above that are used to manufacture the chemical fuels upon which they are based.

I’ve mentioned in previous blogs the future for solar, photovoltaic and any other intermittent energy sources is relatively bleak since the options for storing energy from these sources is so constrained. In fact, only pumped hydroelectric and pressurized gas have been proven so far to be commercially viable.  Better yet, both are scalable.  However, both of these storage systems have their own unique geographic weaknesses:  hydroelectric requires a convenient nearby large elevation change and pressurized gas is normally contained in an artificial cavern formed using hot water in a nearby thick salt bed underground.  The latter is how the US’s strategic oil reserve is stored.

Other technologies, such as batteries, capacitors and flywheels fall short due to economic and/or technical shortcomings.  Although each approach has its own unique set of weaknesses, the lack of scalability and the high cost of their materials and/or construction are shared liabilities.  Lack of scalability means that each of these technologies requires the addition of multiple identical units in parallel in order to provide commercially useful amounts of energy.

Recently, a lot press has been devoted to the concept of flow batteries.  Flow batteries can be roughly divided into two technologies: molten metal (for example, molten magnesium and antimony separated by a layer of molten salt) and redox (chemistry shorthand for reduction-oxidation).  Both technologies use relatively cheap materials, have long working lives (at least in principle) and are scalable.  Neither technology is ready for commercialization and, as usual, have their own set of complicating issues which need to be solved.  Molten metal flow batteries are problematic because of their high temperatures.  However, my bet is on redox flow batteries because they seem likely to be able to be scaled to residences all the way to industries.

Regarding scalability, any battery’s cell voltage is established by the electrochemical potential of its chemical reactions.  In the case of redox flow batteries, the cell voltage can vary from 1.1V to 1.4V/cell.  Consequently, cells need to be connected in series to add up to the desired voltage of the battery.  Likewise, the cell strings need to be connected in parallel to provide the desired power storage capacity of the battery.  Using an analogy, the difference between a conventional battery like Li-ion and a flow battery,  is that in an array of series- and parallel-connected cells, Li-ion batteries are like a whole set of small internal combustion (IC) engines, each with its own small fuel tank.  A comparable flow battery array is like a whole set of large, powerful IC engines that share an enormous common fuel tank.

Redox flow batteries work somewhat like a fuel cell in the sense that two dissimilar materials are brought into close proximity at a permeable membrane and the potential chemical energy is harvested during an exchange of ions and electrons in a redox reaction (for example, the reversible redox reaction between sulfuric acid and various vanadium salt solutions).  However, unlike a fuel cell, both flow battery technologies work in reverse; i.e. they can store energy or provide energy.  A fuel cell cannot be recharged and is solely a source of energy.

Flow cell scalability is a consequence of the fact that the electrolytes can be stored in arbitrarily large vessels and be brought into proximity for the critical ion exchange chemistry to work without any degradation of the cathode or electrode such as that which occurs in all versions of batteries.  Unlike a battery, there are no electrodes that are part of the electrochemical reaction and therefore, there is no obvious limit on lifetime of the battery.  However, the plumbing and precise design of the redox apparatus of a liquid redox flow battery is daunting.  Furthermore, a useful battery is unequivocally large and heavy.  This means it has value in an electric grid but not in a motor vehicle.  Maybe a ship or locomotive though.

Unlike the liquid metal flow battery, the redox battery operates at room temperature.  However, both are highly efficient, quick responding, have simple state-of –charge indications (by comparison, Li-ion batteries are very difficult to monitor), multiple deep discharge cycle capability without degradation and insensitivity to overcharging.

In short, if flow batteries can be developed to the point where they are commercially available, they may represent the key to the emergence of the Third Industrial Revolution (see my December 31, 2011 blog) based on abundant, yet transient renewable energy sources such as photovoltaics and wind.  The world still awaits the solution to the conundrum of a similarly effective solution for mobile use.

Lately I’ve been writing about the economics of electric vehicles (EVs) and the battery technologies (mostly lithium-ion) being used to drive them.  Or, rather, I’ve been writing about the impossible gap between the cost of such “solutions” when compared to the cost of the conventional means of getting around, mainly with the internal combustion (IC) engine.  Only consumers with discretionary incomes that allow them the luxury of buying EVs can earn bragging rights for their stance on fossil fuels and greenhouse gases.  Well, from where I sit, I say:  “Bravo!  Glad you are doing your part because I don’t see an EV in my future.  I hope you will excuse me because I’m late for work.  I need this job because I am upside-down on my mortgage and I think our seven year old car needs a new transmission.”

What the heck is wrong with this country and its scientists?  We’re the country that succeeded, for better or worse, with the Manhattan Project and with the Apollo Program.  Both of these examples have returned to society and consumers their investments many times over.   Surely we are capable of creating solutions that break the stranglehold of imported fuel and avert the looming disaster of global warming.

A thoughtful and well-read man by the name of Dr. Peter Grossman, a Professor of Economics at Butler University, has written on the subject of why most government funding and sponsorship of many different types of alternative energy technology development has not yielded results that can be seen as successful or even confidently viewed as capable of leading to energy independence.  He makes his points succinctly and much better than I, in a white paper he gave in 2008.  See the link to his paper at: 

http://www.altenergystocks.com/archives/2011/02/alternative_energy_technologies_and_the_origin_of_specious.html

The gist of his paper is the observation that successive US administrations from Nixon to Obama have championed numerous alternative energy schemes by providing grants, loans and rebates in the hope that these stimuli can make the difference between high cost demonstration projects and widespread adoption of new technologies by consumers and industry.  Currently the Obama Administration is actively promoting vehicle electrification by using the Presidency as the “Bully Pulpit” and by helping pick the winners with generous grants and low cost, Government-guaranteed loans.

Dr. Grossman points out three fallacies in the Federal Government’s approach to encouraging technological innovation over the last sixty years:

• An inability to distinguish between the technologically possible and the economically desirable;
• A belief that intervention can force innovation and overcome technical challenges on time and within budget; and
• A failure to recognize that generous subsidies invariably lead to increased demand for more generous subsidies.

The fallacies of the first two bullets are partly based on the results of the Manhattan and Apollo Programs where neither program had any constraints imposed by economics.  In addition, the current desire for energy independence in no way matches the urgency of live-or-die imperative to succeed with the Manhattan Project or the emotionally stirring call by JFK to demonstrate the supremacy of the United States by landing men on the moon by the end of the decade.  Both programs met with success but were funded and executed at the Federal level where national policy trumps economics. Not so with the multitude of projects funded by the Government to promote energy independence and clean, renewable energy at the consumer level.

Back to battery technology, current Federal programs are inadvertently aimed at promoting solutions in search of a problem.  The solutions offered?  High cost, bulky, heavy, mobile power sources with finite lifetimes.  The problem being solved?  Beats me.  Certainly not energy storage for EVs.  I’ll entertain alternate suggestions.

Lest I get too cocky about my opinions, I’m reminded of an old saying:  “It takes a craftsman to build a barn.  Any old jackass can kick it down”.   Meaning, it’s easy to point out the flaws in the US energy policy.  It’s quite another thing to propose a better solution.  In my opinion, a temporary alternative may lie with the relatively recent discovery of the Marcellus gas shale underlying most of Pennsylvania and part of New York, combined with the still nascent technology of hydraulic fracturing.  This convergence of an unusable resource with a new recovery technology promises to eventually yield vast amounts of previously economically unrecoverable natural gas in the US.  What’s better, similar deposits can be found in Britain, Eastern Europe, China, India and Australia. This sudden, world-wide windfall of natural resources certainly suggests investing more in an interim energy policy focused on compressed natural gas (CNG).  This energy source may form the bridge between petroleum and whatever clean, economic and renewable energy source that may arise in the future.

I am all for altruism – as long as I can afford it and I am not overly inconvenienced.  I guess that places me in a category with most middle class Americans.   What the heck am I talking about?  In the present case I am talking about the rationale for supporting the US Administration’s push to encourage adoption of electric vehicles (EVs) as our primary mode of personal transportation.  In the abstract, the notion is that EVs will contribute to the reduction of our country’s dependence upon oil imports and, at the same time, reduce greenhouse emissions for the entire planet.  For the record, I strongly support both objectives.  However, the current cost of EV batteries is so high that it makes no economic sense for most consumers to consider buying an EV compared to conventional vehicles.  Thus, if one does buy an EV, it is pure altruism.

It is no longer news, or even a revelation, that all known EV battery technologies offer limited driving ranges (100 miles or less) even in severely down-sized cars and are prohibitively expensive for the majority of the car-buying population, even with government subsidies.   Never mind, some say.  Most people drive their cars less than 100 miles a day, primarily for driving to and from work, and with rising gasoline prices, the extra vehicle costs are eventually offset by lower operating costs – especially after a sizeable subsidy from the taxpayers.  (Ahem!  That’s you.)  Furthermore, our electric generating plants that recharge the batteries use mostly domestically-produced coal or natural gas and technologies exists to scrub their emissions and sequester their greenhouse gas emissions.  Finally, if we convert to mostly nuclear electric plants like the French, most of these inherent pollution problems go away entirely.

Actually, most of the preceding paragraph is substantially true.  (We’ll leave nuclear waste disposal for another blog.) What’s the problem? 

To begin with, a large portion of the American public lives from paycheck to paycheck.  This means that we live and die by our monthly cash flow.  I don’t give a fig about recovering my investment in an EV in four or five years based on energy cost savings.  All I care about is:  what’s my monthly payment?  Also, I have a hard time supporting two cars, unless one of them is an old beater.  I can’t afford an expensive car for just commuting and still have a decent second car for my entire family for use for those not-so-infrequent round trips of longer than 100 miles.  Finally, explain to me again how I am helping the planet’s greenhouse gases while half the world’s population in China and India are still putting around in their petrol-powered econo-boxes.  And will be doing so for as long as anyone can see because their batteries cost too much too.

It seems to me that the US market for EVs will saturate at just a minor fraction of total vehicles sold.  Mostly those of greater means who can afford altruism will be the customers.  Recent census figures show that that sector as remaining relatively fixed in size in the US  but richer than ten years ago.

The outlook in the EU is not too much different.  Granted, as an economic group, they are more accustomed to small but still expensive cars and high fuel prices.  Furthermore, they have vastly better access to alternative mass transit compared to those of us in the US.  So much for the good.  But don’t rely upon higher standards of living  to make up the difference in adoption of EVs in the EU.  Recent case in point:  The violent reaction to increasing the minimum retirement age in France from 60 to 62.  A generation ago, France adopted a 35 hour work week and an early retirement age of 60 to encourage higher employment.  Didn’t happen.  French employers absorbed the loss in productivity and failed to add to their workforce.  The bottom line is that citizens in the EU are no more keen to sacrifice their personal economic well being than we Americans. 

The only plausible solution to the conundrum of the incompatibility of good public policy with the bad economics of EVs is to get creative with how consumers can acquire their batteries at a fraction of their present cost (US$15 – $20 thousand per vehicle).  A little known oddity of lithium-ion batteries is that their useful life in a vehicle is short.  Such a battery pack will still have about 80% of its useful life remaining when it is no longer considered useable in a car.  This means that the battery pack will have a high residual value if it can be repurposed to be used in standby power applications (called “peakers”) for electric utilities or as a storage unit for excess energy created by wind or solar generating installations.  If a consumer is able to lease the battery pack (which is after all, just amortizing the depreciation of frst 20% of the life of the battery pack) the lease payments could be rolled into the monthly finance payment the consumer makes for the purchase of the car — commonly a 48 to 60 month loan in the US.  With continued incremental improved costs of batteries, such a financing plan may be affordable for a much larger segment of the population.  However, for this to happen, a secondary market for battery packs needs to be established.  There’s is a lot of money for someone to make, but the business will start slowly.

The point of this blog is that without creative financing, EVs will remain remain only marginally more feasible for US taxpayers than they were over a century ago – when they were quickly trumped for passenger vehicle use by the combination of the high energy density and affordability of gasoline with the internal combustion engine.  Plus ça change, plus c’est la même chose.

I am certain that most of you who bother to read my blog are the types who stayed awake in history and the various science classes we all attended in school.  Because you stayed awake, you are likely to recall that a self-powered vehicle is a rather old concept with most of its roots in Europe.

For instance, the first self-powered conveyance may have been a locomotive owned by the Middleton Railroad, chartered in Leeds, England in 1758.  The first self-powered vehicle to not run on rails was built by Nicholas Cugnot in France in 1769.  It was steam-powered and beastly heavy.  Then came Robert Anderson’s battery powered vehicle in Scotland in 1832.  And at long last, an internal combustion powered horseless carriage (literally) was patented in Germany in 1879 by Karl Benz.

In view of the chronology of the various types of self powered vehicles, it shouldn’t be much of a surprise that the very earliest commercial automobiles were either steam or electric powered.  This fact is often overlooked since their period of dominance was short-lived and a very long time ago.  The shortcomings of steam and primitive lead-acid batteries are well known.  Internal combustion engines got a fast start due to the mechanical simplicity of the old low compression engines and, most of all, the energy density and portability of gasoline.  This is despite the fact that there was no gasoline distribution infrastructure, no useful roadmaps or even named roads and finally, nearly no roads suitable for wheeled vehicles.  Mud as far as the eye could see.  Oh, and don’t forget pneumatic tires that couldn’t survive but a few miles on such wretched roads.

Well, here we are at the turn of the first decade of the twenty first century and for more than a century, gasoline powered vehicles have reigned supreme on the world’s roads and highways.  How does this state of affairs manage to persist for over a century and likely for decades longer?  Ironically, most of the trains now used in highly developed countries are either purely electric or diesel-electric.  The latter, diesel electrics, claimed the title of the first hybrid conveyances over sixty years ago.

Short answer?  A century plus of brilliant engineering of the internal combustion (IC) engine making it vastly more fuel efficient (more power per cc of engine displacement per liter of gasoline) and the inherently high energy density and portability of gasoline versus the same amount of time (but significantly less effort) of brilliant engineering making very significant improvements to battery chemistry (example:  lead-acid to lithium ion).  And the costs, which are more-or-less related to KWH/KG for comparison’s sake, are not budging.  Not that there was a contest per se, but the outcomes of the parallel development of these alternative energy sources have been starkly different.  And frankly, there doesn’t appear to be much on the horizon to change this state of affairs.

Don’t misunderstand me. A huge effort is underway around the world to make a quantum change to the current state of battery technology.  Unfortunately, battery cell improvements tend to be incremental and the costs remain stubbornly high – at least when compared to an alternative IC engine.  A worrisome side note to the state of the art battery technology is that virtually all of these technologies depend upon exotic and rare elements concentrated in just a few locations in the world.  Afganistan, for example.  We’ve already seen China economically punish Japan by limiting Japan’s access to China’s reserves of rare earth elements.

Many of these  incremental improvements to batteries result from tweaking various cell chemistries and/or exploiting the novel characteristics of new materials such as nanoparticles.  However, just like previous focused efforts to improve video recording that became the battle of standards (Beta vs. VHS and HD DVD vs. Blu-Ray), the market is unintentionally being used to sort through the multitude of candidate battery cells to establish a standard battery.  On second thought, this analogy is not particularly apt, since each of the aforementioned recording technologies were, in fact, the joint output of multi-company consortia.  These consortia presented the market with an “A” vs. “B” choice.  In contrast, battery technologies are being pursued by literally dozens of companies world wide and the market is being presented the choice of “A” vs. “B” through “Z”.  Not exactly the right environment for a quick shake-out.  Neverthess, until some degree of standardization occurs, it will be difficult for manufacturers to acquire sufficient volumes of cells to drive the cost of the technology down a learning curve.  Thus, the costs will remain high.

Aside from cost, if you are a manufacturer of hybrid electric vehicles (HEVs) or electric vehicles (EVs) when you commit to use a particular type of cell, there is a whole cascade of consequences that result from that decision that will make you disinclined to change to a different battery using a different chemistry – especially if only to capture another marginal improvement in the technology.  This is because each particular cell chemistry results in a different cell voltage, energy density, form factor and charge/discharge characteristic.  Consequently, your assembly of battery cells (the battery pack) will be a particular size, weight and physical configuration and the charging and charge state monitor electronics will all be peculiar to that exact cell chemistry.  Change the cell chemistry and all of those variables will change.  That means different costs to manufacture and different applicability to various HEV and EV models.

So, until HEV and EV batteries finally become standardized like the familiar AA, AAA, C, D and 9V battery configurations with essentially similar charge/discharge characteristics and battery state monitoring requirements, every choice of cell technology for these vehicles will result in a sub-optimum solution of some sort.   The world awaits the big shakeout.  But don’t hold your breath, because there’s no end in sight for the quest of the holy grail of batteries.  In the meantime, EVs for short range daily commutes and HEVs for longer trips will be the best solutions you can buy.  If you can afford them.

Just in case you’re thinking about fuel cells, you are on the right track.  Unfortunately this highly promising technology has been stalled in a time vortex for decades and a practical commercial fuel cell perpetually remains ten years away.

By the way, have you ever wondered why there’s no A and B cells?  It’s simply that their primary use was to power vacuum tubes, especially in radios in automobiles.  They are just not needed any more.