A Comparative Life Cycle Assessment of Hydrogen Production & Storage with Renewable Energy Source and Grid Electricity Source

Abstract

The role of electricity is becoming significant in our advancing world. Currently, Ireland’s energy mix heavily relies on carbon-polluting fossil fuels, posing an environmental challenge. As per the Paris Agreement 2015, Ireland is ambitiously targeting to meet net zero carbon dioxide (CO2) emissions by 2050 and a 51% reduction by 2030. The country is shifting towards renewable energy sources to generate power to achieve this target. With abundant wind energy available, Ireland can meet its goal. However, due to the intermittent availability of wind energy, an energy backup for power generation is necessary. The use of curtailed or dedicated wind for producing hydrogen gas through electrolysis, and storing it in underground salt caverns is one approach to the problem. Northern Ireland has a rich source of Permian salt deposits offering a better place to store hydrogen which can be withdrawn for electricity generation, or used as fuel in transportation sectors. The Life Cycle Assessment (LCA) of the hydrogen systems can scrutinise the environmental impact of carbon emissions. This study analyses routes to reduce the environmental impact by evaluating polluting hotspots during the construction and operation phase of the system. This paper compares the impacts of the LCA on a hydrogen system which consists of a wind energy source for hydrogen production through electrolysis, transportation in pipelines and compression before storing it in salt caverns. A comparative analysis is carried out with the LCA of the hydrogen system with an electrical grid supply source. The results show that the impacts contributed by a renewable source are less than the electricity from the grid for the island of Ireland.