Plastic water bottles, found in family refrigerators and office coolers, are packaged in polyethylene terephthalate (PET) bottles. The amount of PET used per bottle depends on the style, thickness, and size of the bottle. PET is produced from fossil fuels — typically natural gas and petroleum.

The PET production process also relies on other energy sources, including thermal and electric sources. The European plastics manufacturing industry found that producing a tonne of PET resin requires 83,000 millijoules of energy. They also estimate that transporting the resin and converting it into bottles requires an additional 20,000 MJ of energy per tonne of PET. When put together, the energy to produce and transport the PET resin, and then mold it into bottles, totals approximately 100,000 MJ per tonne of PET.

(Source: Pacific Institute)