Bottled Energy
When it comes to reusable metal water bottles, not all are created equal. But we’re not talking about the obvious characteristics, like shape, size and color. We’re talking about how the bottle was physically produced. What goes into the production (raw materials, energy, etc) of various metal water bottles?
Reusable metal water bottles are typically made from two types of metal; aluminum or steel. Common aluminum bottles you’ll see are Sigg and Laken, while our bottles, and Klean Kanteen’s are made from stainless steel. Let’s take a look at the difference between the two types of metal and how they play into the production process of each type of bottle.
Aluminum
Aluminum has the advantage of being the most common metal in the Earth’s crust. Unfortunately, it’s rare in its’ free form and is usually found trapped in various types of ore. Most commonly bauxite ore. In order to be used in production applications (like bottles), the aluminum has to be extracted and refined. But because aluminum bonds strongly to oxygen this process is extremely energy intensive. So much so that aluminum has earned the nickname “solidified electricity.” In fact, the EPA has estimated that as much as 2-3% of all electrical use in the U.S. goes toward the production of aluminum.
So just how much electricity does it take? An MIT Study found that the production of just 1kg (2.2lbs, or about seven 1.0L Sigg bottles) of aluminum requires 290 MJ (or 80 kilowatt-hours) of energy. That’s enough to power your average 60 Watt light bulb for about 1,300 hours. Alternatively, 80 kilowatt-hours could power your average personal computer (with an LCD flatscreen) for about 760 hours!
And it’s not just lots of electricity that goes into aluminum production. It requires approximately 12kg (26.5lbs) of raw material to produce just 1kg (2.2lbs) of aluminum. This means a lot of ore needs to be mined to produce a small amount of aluminum.
Stainless Steel
Unlike aluminum, steel is an alloy. Meaning it contains two or more metallic or metallic and non-metallic elements fused together. The largest constituent of steel is iron, which is the fourth most common element in the ground. Depending on what other elements are added, different types of steel are created. To make stainless steel, extra chromium is added to the mix. And chromium is what gives stainless steel its self-passivation characteristics.
For several reasons, stainless steel requires far less energy to extract and refine than aluminum. The production of 1kg of stainless steel requires about 37 MJ (or 10 kilowatt-hours) of energy. Meaning it takes about 85% LESS energy to produce the same amount of stainless steel than aluminum. To use the personal computer analogy from before, the energy required to produce about 30 1.0L stainless bottles could power your average personal computer (with LCD flatscreen) for about 90 hours. So from an energy perspective, stainless steel is a far more eco-friendly choice.
And other studies have shown the production of stainless steel produces considerably less greenhouse gas emissions than that of aluminum.
Summary
If you’re concerned with the environmental impact of your bottle’s production process, stainless steel is the better of the two options. It uses considerably less electricity and raw materials, and produces less GHG emissions (greenhouse gas emissions) to produce a stainless steel bottle than an aluminum bottle. And while both aluminum and stainless steel use some raw materials (which must be mined), many facilities use high amounts of recycled material. In fact, Pura Stainless bottles are composed of approximately 60% recycled stainless steel. Combined with the number of disposable bottles you’ll spare from landfills, your Pura bottle is one of the most eco-friendly purchases you can make.