Renewable and non-renewable energy consumption, energy technology investment, green technological innovation, and environmental sustainability in the United States: Testing the EKC and LCC hypotheses with novel Fourier estimation.

The energy sector represents one of the key contributors to environmental degradation. In this context, actions taken within the energy sector are paramount in the global effort to combat climate change. This study aims to investigate the impacts of renewable and non-renewable energy consumption, energy technology investment, and green technological innovation on environmental sustainability in the context of EKC and LCC hypotheses in the USA from 1980 to 2015. While many studies in the literature focus on the EKC hypothesis, this study offers a comparative analysis of the EKC and LCC hypotheses with relevant variables. For this aim, the study uses the novel Fourier estimation methods. According to the results, the EKC and the LCC hypotheses are valid in the USA. Moreover, non-renewable energy consumption increases the ecological footprint. On the other hand, non-renewable energy consumption decreases the load capacity factor while renewable energy consumption increases it. Finally, energy technology investment and green technological innovation have an insignificant impact on the ecological footprint and the load capacity factor in both models. All results except energy technology investment and green technological innovation are consistent with our expectations. The USA has the potential to realize green growth. Policymakers should support the green technological innovation process and increase green investments.