Hydrogen is the most common element in the universe and will soon be a primary energy source on earth. As the world is becoming more familiar with this zero-emission energy, we’re also becoming aware that not all hydrogen production is equal in environmental impact. Some methods convert water, relying on electricity either from the power grid or renewable energy sources such as wind turbines, solar panels, and hydroelectricity (known as electrolysis). Other forms of production take advantage of natural gas through steam methane reforming (SMR). Whatever the methodology used to create hydrogen, there are variables within these methods that affect the overall carbon impact of the hydrogen.