Lead Prices And Electric Vehicles
The common lead/acid battery based on lead/lead oxides with dilute sulfuric acid electrolyte is by far the most widely employed source of rechargeable electric power, because lead being a low cost metal, it is relatively inexpensive. One such battery cell produces about 2.1 volts; the common auto battery contains six cells in series. Such batteries in various configurations effectively power everything from diesel electric submarines to electric scooters. There are however some downsides to the lead/acid battery, the most important being lead’s inherent toxicity.
Lead metal, its alloys and compounds are all poisonous. Acute lead poisoning can be deadly, and low-level chronic poisoning produces brain damage, to which children are more susceptible than adults. Lead exposure is a public health concern, and it is due to this that the gasoline additive lead tetraethyl was phased out. The lead/acid battery requires the safe mining, fabrication, distribution, use and eventual disposal of the inherently toxic material lead.
Another disadvantage is the battery’s weight. Lead is a relatively dense metal, therefore lead batteries are heavy, with a low power to weight ratio. Research is underway to reduce the lead content without affecting performance, making the power/weight ratio more attractive.
Despite these disadvantages the lead/acid battery has many applications in modern technology, due to its relatively low cost. At this time, with no cost-effective substitute in sight, its general replacement is unlikely.
The price of lead is an important factor impacting lead/acid battery cost. Fabrication and assembly of the internal components and plastic battery cases are also important, as are shipping costs. The dilute sulfuric acid electrolyte is inexpensive, but its environmentally safe disposal presents a problem due to acidity and lead sulfate content. Discarded lead/acid batteries should be recycled.
Lead non-battery applications include use in electrical and non-electrical solders, lead shot and bullets, paints, ceramic glazes, fishing sinkers, radiation shielding, leaded glass, etc. There is no good substitute for lead in solders, bullets and radiation shielding, but otherwise its general use in developed countries is gradually being phased out.
As an interesting historical note, lead plumbing was employed by the Romans to deliver drinking water, and it has been suggested that this caused the decline and fall of the Roman Empire. Our word Plumber comes from the Latin for lead, Plumbum, and lead’s chemical symbol is Pb. There is a saying about the importance of plumbers, which is that in America even a plumber could be President, if he could afford the cut in pay.
Lead is traded daily on the London Metals Exchange, www.lme.co.uk, which states it is “The World Centre For Non-Ferrous Metals Trading.” As of May 14, 2008 the price of lead is given as $2,283/ton or $1.1415/pound. The August 2009 15-month forward contract prices lead at $2,350/ton or $1.175/pound. Evidently the Exchange traders expect that 15 months from now the price of lead will have advanced 3.35 cents a pound, for an annual price increase of 2.51 cents/pound, or 2.2%. This is consistent with general price inflation. The lead price however has risen considerably from what is was as recently as early 2006, when it sold in the range of 50 to 60 cents per pound, and in 2007 it was around $1.50/pound. There has been price volatility, but the lead price has now settled to a relatively stable level, at about twice what it was in early 2006.
The price of lead depends on supply and demand. The supply is stable, and since lead is a plentiful, easily and widely mined and refined metal, any supply disruption would probably be temporary.
Let us try to look at the future use of lead/acid batteries in transportation. The standard auto/truck employs one battery. Near-future Hybrids and pure EV’s would probably employ a number. Therefore transition from liquid fuels to EVs would increase the use of lead, IF lead/acid batteries were used to power the Evs.
However there are a number of alternate battery systems in development that do not employ lead. With the present intensive research something other than the lead/acid battery may well be developed and employed for EVs, where weight is important. Then the price of lead would probably not advance, and could decline.
Let us look at the future use of lead in developing countries such as China and India. There is increasing use of lead for auto and truck batteries, solders, bullets, paints, glazes, etc. The increasing demand helps support lead’s price. Future lead prices will probably depend primarily on the following two considerations:
(1). Since every liquid fuel auto uses a lead/acid battery, the fewer such autos the fewer batteries. According to current auto sales trends, near term we will probably see battery uses increasing in the developing, and declining in the developed countries.
(2). Industrial uses of lead as in solders and paints are increasing in developing countries and decreasing in developed countries. Near term the increasing and decreasing uses will probably somewhat balance each other out overall.
Another consideration is the recycling of lead/acid batteries. Lead has been so cheap that in the past despite environmental concerns many discarded batteries were not recycled. Over time increased emphasis on recycling could work to help increase the supply and so reduce the price of lead.
Traders on the London Metals Exchange are world experts on lead prices, and they foresee a near term lead price of about $1.14/pound, with about only a 2.2% increase in lead prices over the next 12 months.
If one makes the assumptions that liquid fuel prices will increase, and that most EVs of the reasonably near future will not be powered by lead/acid batteries (although hybrids use them), it appears likely that the price of lead will remain relatively stable and not spike up or advance markedly. IF however the lead/acid battery does power future EVs, then the demand for lead will probably increase, and so will the price.
Summing up, it appears the price of lead will remain relatively stable for at least the next 12 months, increasing only a few percent due to general inflation. Longer term it will depend mostly on whether or not an overall better non-lead battery appears and is increasingly employed. If it does, lead’s price will probably decline, if not it will probably stabilize and could even advance.
Luckily lead is a plentiful metal, and any shortage and corresponding price spike would probably just be temporary.
Dr. Duke has a degree in chemistry and experience in trading commodity futures. He has been published in Futures magazine. Copyright Phil Duke, PhD 2008
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