Promising pathways: The geographic and energetic potential of power-to-x technologies based on regeneratively obtained hydrogen

Abstract

In light of advancing climate change, environmentally-friendly methods for generating renewable energy are being employed to an increasing extent. This use, however, leads to rising spatial and temporal disbalances between electricity generation and consumption. To address the associated challenges, Power-to-X technologies are considered to harness surplus electricity from renewable sources and convert it into an alternative energy source that can be utilized, transported and stored. The aim of this paper is to compare four different Power-to-X technologies, whereby surplus electricity “Power” is converted to chemical entities “X”. It is shown that the implementation of PtX technologies and a shift of energy distribution to other transport methods could significantly relieve the electricity grid. Moreover, by converting the electricity from renewable sources, like wind farms, into chemical energy sources, the PtX concept offers the opportunity of making larger quantities of energy storable over longer periods of time. By considering a model case where electricity generation and consumption are several hundred kilometres apart, the generation of fuels emerges as a technology with the highest potential to mitigate climate change. Also with regard to transport, fuels emerge as the most favourable option for transporting chemically bound energy. Common to all options is the yield of a significant stream of oxygen as by-product. Utilizing this oxygen may be one of the key factors towards improving the economic viability of Power-to-X technologies.