  This paper uses established and recently introduced methods from the applied
mathematics and statistics literature to study trends in the propagation and
capacity of low-carbon hydrogen projects over the past two decades. First, we
judiciously apply a regression model to estimate the association between
various predictors and the capacity of global hydrogen projects. Next, we turn
to the geographic propagation of low-carbon hydrogen projects, where we apply a
recently introduced method to explore the geographic variance of hydrogen
projects over time. Then, we demonstrate that most geographic regions display
linear growth in cumulative plants and apply distance correlation to determine
the nonlinear dependence between the two most prolific regions - North America
and Europe. Finally, we study the time-varying regional consistency between the
contribution of green vs fossil fuel plants to the total number and capacity of
hydrogen plants.
