*Article* **The Impact of Economic, Energy, and Environmental Factors on the Development of the Hydrogen Economy**

**Justyna Cader \*, Renata Koneczna and Piotr Olczak**

Mineral and Energy Economy Research Institute, Polish Academy of Sciences, 31-261 Cracow, Poland; rkoneczna@min-pan.krakow.pl (R.K.); olczak@min-pan.krakow.pl (P.O.)

**\*** Correspondence: jcader@min-pan.krakow.pl

**Abstract:** This article attempts to model interdependencies between socio-economic, energy, and environmental factors with selected data characterizing the development of the hydrogen economy. The study applies Spearman's correlation and a linear regression model to estimate the influence of gross domestic product, population, final energy consumption, renewable energy, and CO2 emission on chosen hydrogen indicators—production, patents, energy technology research, development, and demonstration budgets. The study was conducted in nine countries selected for their actions towards a hydrogen economy based on analyses of national strategies, policies, research and development programs, and roadmaps. The results confirm the statistically significant impact of the chosen indicators, which are the drivers for the development of the hydrogen economy from 2008 to 2018. Moreover, the empirical results show that different characteristics in each country contribute to the development of the hydrogen economy vision.

**Keywords:** linear regression model; Spearman's correlation; national hydrogen strategies; hydrogen economy implementation
