How Much Does it Really Cost (the Planet) to Make a Penny?

Ah, the lowly penny, the one-cent coin graced by Lincoln’s face: fountain fodder, lounge chair lint, tollbooth reject and city litter. Kids love to fill their piggy banks with them, and untold billions are parked in collection jars and other dark, forgotten places.

Most people know that pennies cost the government more to make than they're worth, even after the U.S. Mint switched to using mostly zinc in 1982. They may not know that making all those pennies has a serious environmental impact, from raw ore, to smelter, to mint, and then to banks before finally being dropped on the street or dumped into a coin kiosk or a fountain.

So with those costs also in mind, is it possible to make the penny greener?

Christina Cogdell, an associate professor of design at the University of California Davis, asks her undergraduate students to parse out each material comprising a particular product, all the way from raw material to burial. Two years ago, three of her students chose the penny.

Christine Knobel, Nicole Tan and Darin Reyes spent a semester analyzing the information they could find to make an assessment of the penny’s ecological footprint. Their conclusion was the true cost of making a penny adds up to much more than 1.43 cents, or what the Mint reports it cost to produce a one-cent coin last year, though they were not able to individually parse out the incremental cost per coin of mining, smelting, minting and trucking the coins—all energy intensive processes.

“We were surprised about the lack of information,” said Knobel. “We weren’t able to find out anything more detailed.”

To be fair, the current production cost is down from the 1.66 cents it cost in 2014, and the continuation of a years-long trend and efforts by the Mint to increase efficiency as well as sustainability.

The Mint itself has tried to find out if making coins, including the penny, out of different metals might make them cheaper (and maybe greener) to produce, but it concluded, that for the penny, “there are no alternative metal compositions that reduce the manufacturing unit cost of the penny below its face value,” according to a 2014 report to Congress.

Each Mint facility conducts monthly environmental compliance audits and aims to reduce direct emissions by 33 percent by 2020. The Denver Mint is already 100 percent wind-powered, and the power-hungry stamping presses now have a sleep mode to reduce power consumption when not in use.   

Between weak economic demand and environmental impacts, nearly a dozen countries have concluded that the penny’s not worth it. Canada abolished its penny in 2012, joining countries including Australia, Brazil, Finland, New Zealand, Norway and Israel.

“The Government of Canada mainly phased out the penny due to its rising cost of production relative to face value, the increased accumulation of pennies by Canadians in their households and the significant handling costs the penny imposes on retailers, financial institutions and the economy in general,” said Canadian mint spokesman Alex Reeves. “Environmental considerations did play a role as well, since ending production of a coin that was scarcely in demand was beneficial to the environment.”

The Mint has made pennies of 97.5 percent zinc and 2.5 percent copper since 1982. Knowing where the raw metals come from might make it possible to estimate the total cost of the product stream. Good luck with that.

Jarden Zinc Products, the sole company that produces penny blanks for the U.S. Mint to stamp into finished coins, declined to comment on any aspect of its production or the sourcing of their metal other than to say it is “all completely recyclable,” according to Mark Blizard, the company’s vice president of coinage sales. A company product sheet states the zinc is “mined, processed and formed in America,” describing the zinc as coming from Tennessee mines owned and managed by Nyrstar, which also operates the country’s only primary zinc smelter. Yet Nyrstar company representatives assert that Jarden is not one of their clients and has no direct connection with the penny-making process.

Adding to the confusion, the Mint itself reported in 2014 that the zinc comes from Canada. (At least the copper is easier to track: All the copper used by the Mint more than likely originates in the United States.)

At any rate, pennies made up 56 percent of the Mint’s production run last year. And a little napkin math shows that as a percentage of metals destined for consumer uses, pennies aren’t exactly chump change.  

In 2014, the Mint produced 8.15 billion one-cent coins. That’s 22,450 tons of pennies, which equates to 21,888 tons of zinc and 562 tons of copper. The same year, 651 tons of copper was used to make "consumer products"-- including appliances, ammunition, electronics, utensils and coins. That means 86 percent of the copper destined for consumer products was used just for pennies. (Those 651 tons don't include copper used for non-consumer goods, like airplanes, building hardware, and more.) For zinc, the percentage is smaller—2 percent of the 1.1 million tons of refined zinc consumed in 2014—but still enough to be statistically significant.

Getting all that ore out of the ground is costly, in terms of carbon dioxide emissions, pollutants, and power consumed. A 2009 analysis found that Western copper mines use 35.7 gigajoules of energy per ton of copper produced, with zinc and lead mines fairly more efficient, using only 6.6 to 6.8 gigajoules of energy per ton. The report also found that greenhouse gas emissions for copper mining operations in 2007 averaged 2.45 tons of carbon dioxide emitted for every ton of copper produced, compared with .58 tons of carbon dioxide per ton of zinc.

Copper mines, located mostly in Arizona, tend to be of the open-pit variety, which allows more substances to be released. Zinc mines can be open or closed; Red Dog Mine, in Alaska and the country’s largest, is an open pit mine, and has been embroiled for years in water pollution and toxic waste fights. Much of the rest of the country’s zinc is produced in Tennessee, whose emissions are limited by virtue of being underground.

Here’s an idea of the torture zinc must go through before it is pure enough to be lacquered with copper and punched into a coin. Mining involves blasting and chipping zinc-containing sphalerite ores away from the surrounding limestone, then crushing and processing the ores in chemical baths that separate the zinc from other minerals. At the smelter, raw zinc is roasted to remove sulfides, then sent through a leaching and purification process.

The main byproducts of this process include sulfuric acid, which is collected for resale, and sulfur dioxide, which can cause acute respiratory distress. Mercury is another impurity removed during this process. Nyrstar’s operations, both at the mining and refining levels, are well under state and federal limits set for releases of other toxins including cadmium and lead, though the company was fined once in 2009 for a release of cadmium into the Cumberland River in excess of permitted release limits.

After being rolled out to the proper thickness at Jarden Zinc, coins are stamped out into circles called planchets, which are polished and then electroplated with pure copper. Shipped to the U.S. Mint in either Denver or Philadelphia, die presses stamp Abraham Lincoln’s likeness and a federal shield onto either side of the coin with 35 tons of force. After inspection, coins are trucked to one of 12 Federal Reserve banks. 

Despite the fact that the United States recycled 71.8 million tons of metal in 2013, the most recent year for which data is available, not a single penny made today is recycled, at least by the Mint. Nor are any coins at the moment. In part as a response to abuses of the Mint’s long-standing mutilated coin reclamation program, such as a recent $5.4 million plot by several metal scrap recyclers to profit from counterfeit coins imported from China, the Mint temporarily suspended the program.

Pennies have an estimated 25-year life span, but because so many of them fall through the proverbial cracks, demand from year to year varies. People do try to “recycle” them, though: the company known for its green-and-white coin-collecting kiosks, Coinstar, processed more than 18.5 billion pennies in 2015, which are all eventually deposited with banks, said Susan Johnston, a representative of the company.

So whither the penny? If it can't be made greener, why not get rid of it entirely?

For decades, anti-pennyists have trotted out arguments advocating for the penny’s elimination, mostly because of economics. Former Arizona congressman Jim Kolbe introduced three bills from 1989 to 2006 to try and get the government to ditch its smallest denomination; more recently, John Oliver ended his 2015 season with a viral rant on the “garbage” currency.

On the other hand, plenty of people are fine with the penny. For some, its chief value is sentimental, a cultural icon; others worry that customers will suffer if prices get rounded up rather than down.

There's one group that really wants to keep the penny around, though: Jarden Zinc Products, whose current contract with the Mint is valued at $425 million, according to Mint spokesman Michael White.

For Knobel, the UC Davis student, the answer seems clear: economically as well as environmentally, it makes sense to get rid of the penny.

“After doing the research, it became clear that the penny isn’t needed,” she said. “If the Mint is trying to reduce energy, why not reduce it by a whole coin? That would be a huge step in the right direction. I don’t think it’s going to be that big of a deal.”

Don’t agree? Ask the former director of the U.S. Mint, Philip Diehl, who said at the end of 2015 that the penny was “beyond hope.” 

Michelle Z. Donahue | | READ MORE

Michelle Z. Donahue is a freelance writer who covers nature, science and technology. She is a regular contributor to Smithsonian.com.