Coal-fired Pizza: One Way of Looking at the Nexus

A few years ago, coal powered half of the electricity in the US. With a newfound abundance of natural gas and increasing reliance on renewable energy, coal’s place in the fuel mix has declined. Moving beyond coal is undoubtedly a good thing for the environment, but there is one use for coal that might not be too bad: firing a pizza oven.

Yes, you read that correctly. Coal-fired pizza has re-emerged as an artisanal method of pizza making. In their E&E piece, Daniel Cusick and Saqib Rahim wondered whether coal-fired pizza could take a slice out of the coal industry’s slump. The short answer is a pretty obvious no, given that coal-fired pizza uses high grade coal called anthracite, whereas coal used for power production typically uses lower grade lignite and bitumen

Anthracite coal has a high carbon content and few impurities so it’s good to know you won’t be getting mercury as an extra topping on your slice. Anthracite also burns at a high temperature which, along with the smoke, gives the pizza a distinct flavor that people swear by. 

Cusick and Rahim’s article gives an excellent tour of the many restaurants (primarily in New York City) that serve coal-fired pizza. They also offer a glimpse into the energy-food nexus. In GRACE’s Know the Nexus paper, we also use pizza as a way to think about how food, water and energy are connected. At first glance, it seems pretty basic – dough, tomato sauce and cheese – but look closer and you’ll find that those three ingredients have a rich story to tell.

As a mental exercise, deconstruct a slice of pizza; consider the water and energy required to make it. You need to add water to the flour and yeast to make the dough, but what about the water used to grow the wheat that’s milled into flour ? Or what about the water needed to produce the mozzarella? You don’t see this “hidden water” in your slice of pizza, but it’s there. 

Through a series of studies, the Water Footprint Network (WFN) broke down the water footprint of a margherita pizza (one topped with tomato, mozzarella and basil). A water footprint looks at the direct and virtual water used to produce an item. The WFN found that to make a single margarita pizza requires 333 gallons (1260 liters) of water, enough to fill almost ten bathtubs! 

Producing one calorie of food requires about one liter of water. That means you “eat” more water than you drink.

Now think of the energy going into your pizza. The direct energy that goes into warming the pie (think of the coal) is the tip of the iceberg; there’s also the virtual energy that goes into farming the crops (think tractors and fossil fuels required to produce fertilizers and pesticides), processing and distributing the ingredients, and even the energy that was required to manufacture the pizza oven. 

You might not realize it, but just for a $10 plain cheese pie, you rely on a global distribution network, industrial agriculture, fossil fuels and a lot of water. 

Clearly, water, energy and food are interrelated: you need water and energy to produce food; you need energy to treat and move water, and you need water to cool power plants and to produce natural gas and oil. The deeper you look into these networks, the more complex and interrelated you realize they are. 

The next time you grab a slice of coal-fired pizza you’ll know more about what’s required for each tasty bite, but what about all the other things you consume? Do they also add up to a lot of food, water and energy? And how does your consumption of food, water and energy directly or indirectly impact our natural resources and ecosystems?  Take a broader look with our Know the Nexus paper to further explore the nexus.