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From lab to market, it’s a long haul

The Energy Information Administration has done us an enormous favor by producing a simple chart to make sense of where the development of energy storage technology is going. Energy storage, as the EIA defines it, includes heat storage, and a quick look at the chart reveals that those forms that involve sheer physical mechanisms – pumped storage, compressed air and heat reservoirs – are much further along than chemical means of storage, particularly batteries.

The EIA divides the development of technologies into three phases – “research and development,” “demonstration and deployment” and “commercialization.” It also ranks them according to a factor that might be called “chances for success,” which is calculated by a multiple of capital requirements times “technological risk.”

As it turns out, only two technologies that could contribute to transportation are in the deployment stage while three more are in early development. The two frontrunners are sodium-sulfur and lithium-based batteries while the three in early stages are flow batteries, supercapacitors and hydrogen. The EIA refers to hydrogen as one of the ways of storing other forms of energy generation, particularly wind and solar. But hydrogen is also being deployed in hydrogen in hydrogen-fuel-cell vehicles that have already been commercialized.

Other than building huge pumped-storage reservoirs or storing compressed air in underground caverns, the chemistry of batteries is the most attractive means of storing electricity, which is the most useful form of energy. Batteries have always had three basic components, the anode, which stores the positive charge, the cathode, which stores the negative charge, and the electrolyte, which carries the charge between them. Alexander Volta designed the first “Voltaic pile” in 1800 by submerging zinc and silver in brine. Since then, battery improvements have involved finding better materials for all three components.

Lead-acid batteries have become the elements of choice in conventional batteries because the elements are cheap and plentiful. But lead is one of the heaviest common elements and becomes impractical when it comes to loading them aboard a vehicle.

The great advantage of lithium-ion batteries has been their light weight. The lithium substitutes for metal in both anode and cathode, mixing with carbon and iron phosphate to create the two charges. Li-ion, of course, is the basis of nearly all consumer electronics and has proved light and powerful enough to power golf carts. The question being posed by Elon Musk is whether they can be ramped up to power a Tesla Model S that can do zero-to-60 with a range of 300 miles.

Tesla is not planning any technological breakthrough, but will use brute force to try to scale up. Enlarging li-ion batteries tends to shorten their life so the Tesla will pack together thousands of small ones no bigger than a AA that will be linked by a management system that coordinates their charge and discharge. Musk is betting that economies of scale at his “Gigafactory” will lower costs so that the Model X can sell for $35,000. According to current plants, the Gigafactory will be producing more lithium-ion batteries than are now produced in the entire world.

In the sodium-sulfur battery, molten sodium serves as the anode while liquid sodium serves as the cathode. An aluminum membrane serves as the electrolyte. This creates a very high energy density and high discharge rate of about 90 percent. The problem is that the battery must be kept at a very high temperature, around 300 degrees Celsius, in order to liquefy its contents. A sodium-sulfur battery was tried in the Ford “Ecostar” demonstration vehicle as far back as 1991, but it proved too difficult to maintain the temperature.

Flow batteries represent a new approach where both the anode and cathode are liquids instead of solids. Recharging takes place by replacing the electrolyte. In this way, flow batteries are often compared to fuel cells, where a steady flow of hydrogen or methane is used to generate a current. The great advantage of flow batteries is that they can be recharged quickly by replacing the electrolyte, rather than taking up to 10 hours to recharge, as with, say, the Chevy Volt. So far flow batteries have relatively low energy density, however, and their use may be limited to stationary sources. A German-made vanadium-flow battery called CellCube was just installed by Con Edison as a grid-enhancement feature in New York City this month.

Supercapacitors use various materials to expand on the storage capacity devices in ordinary electric circuits. They have much shorter charge-and-discharge cycles but only achieve one-tenth of the energy density of conventional batteries. As a result, they cannot yet power vehicles on a stand-alone basis. However, supercapacitors are being used to capture braking energy in electric trams in Europe, in forklifts and hybrid automobiles. The Mazda6 has a supercapacitor that uses braking energy to reduce fuel consumption by 10 percent.

The concept of “storage” can be also be expanded to include hydrogen, since free hydrogen is not a naturally occurring element but can store energy from other sources such as wind and solar. That has always been the dream of renewable energy enthusiasts. The Japanese and Europeans are actually betting that hydrogen will prove to be a better alternative than the electric car. Despite the success of the Prius hybrid, Toyota, Honda and Hyundai (which is Korean) are putting more emphasis on their fuel cell models.

Finally, methanol can be regarded as an “energy storage” mechanism, since it too is not a naturally occurring resource but is a way to transmit the potential of our vast reserves of natural gas. Methanol proved itself as a gasoline substitute in an extensive experiment in California in the 1990s and currently powers a million cars in China. But it has not yet achieved the recognition of EVs and hydrogen – or even compressed natural gas – and still faces regulatory hurdles.

All these technologies offer the potential of severely reducing our dependence on foreign oil. All are making technical advances and all have promise. Let the competition begin.

Who Says Cars Have to Fill a Parking Space?

You’ve seen them zipping around city streets or squeezed into some illegal-looking space between a normal car and a fire hydrant.  At first you might have thought they were some kind of joke. Who would drive such a thing?  But the new mini-electrics are catching on and may be on the way to revolutionizing urban driving.

There is now a whole menu of them – the Chevrolet Spark, the MINI E, the Toyota IQ, the Fiat 500. Oddly, many of them are available only in California. That seems like a mismatch because they’re obviously better suited for the densely populated cities of the Northeast than California freeways. But those are the vagaries of state incentives and government mandates.

Most of them have a highly limited range.  125 miles is good and some are as low as 75. (A regular gas-powered vehicle can go 400 miles on a full tank.)  But they’re a niche model, obviously suited for running around town and finding a parking space in the vehicle-choked precincts of places like New York City. They can get up to the equivalent of 125 miles per gallon and with some newer accessories don’t take up to seven hours to recharge. Most important, they are getting down into a price range where they are accessible. Leasing prices are impressive (some of them are only available by lease) and with the incentives that the Golden State is offering, people in California can say they are getting a really good deal.

Here’ a list of some of the contenders:

  • Chevrolet Spark.  Originally produced as the Daewood Matiz by GM’s Korean division, the all-electric Spark went on sale in California and Oregon in 2013.  The car is a 146-inch-long four-door hatchback that sells for $27,000.  With a $7,500 federal tax credit and a $2,500 California rebate, however, it comes in at well below $20,000. The Spark can be leased for $199 a month. With an optional connector, it can be charged up to 80 percent in 20 minutes.
  • Fiat 500e.  An electric version of a car that has been sold in Europe since the 1950s, the 500e went on sale in California last year, selling 645 units. Range is barely 100 miles but it gets the equivalent of 116 mpg. The car is priced at $32,000.  Fiat says it will be available in several more states in 2014.
  • Chrysler’s Smart FortwoThe Smart Fortwo is a model that looks like you could fold it up in your back pocket or park it in your living room. Manufactured in France, it is barely eight feet long. It sells everywhere in the United States. Previously built for gasoline and diesel, the new all-electric model sells for only $12,000 and leases for $99 a month. You’re starting to see them more and more on the streets of New York City.
  • Toyota Scion IQPositioned as a direct competitor to the Fortwo, Toyota’s “city car” sold as a 3-cylinder gasoline engine until the electric version was introduced last year.  Estimated range is only 50 miles with a three-hour recharge, so it’s really limited to city driving. The price is high – $35,000 – and right now it’s only available for fleet purchases and car share programs. The first 30 units were bought by the University of California at Irvine.
  • Mitsubishi i-MIEV EV.  Introduced in Japan in 2008 and soon sold almost everywhere but in the United States, the “i” version was finally brought to these shores in 2011, a slightly larger version with some additional features.  The American version has a range of only 62 miles but was ranked by the EPA as the most fuel-efficient car in America until surpassed by the Honda Fit EV in 2012. It sells for $23,000.
  • Honda Fit EVStill only available on a lease basis, the Fit EV goes for $259 a month. Introduced only in California and Oregon in 2011, it is now available in New York, New Jersey, Maryland, Massachusetts, Connecticut and Rhode Island as well. The car only has an 80-mile range but is highly fuel efficient.

Getting people to accept the proposition of driving around city streets in something that looks like it could be sold on the floor of FAO Schwarz, of course, is an entirely different matter. In test driving a city car for The New York Times, Jim Motavalli reports a neighbor commenting, “It’s adorable, but I’m afraid it would be crushed by a Suburban.” The idea of weaving in and out of traffic in what amounts to a tin can is certainly not for everyone. But electric vehicles have lots of torque at the lower end of the spectrum and can be easily maneuvered. Plus if nothing else, they are loaded with safety features.

To anyone familiar with the dense urban streets of Athens or Buenos Aires, city cars would be a familiar sight. And of course the more there are of them, the less dangerous driving becomes. The progress of mini-cars is slow but you’re seeing more and more of them. In the end, they may revolutionize urban driving.