Power-to-Gas Energy Storage and its Effects on reducing Emissions and improving Energy Security for Ireland

Abstract

The safeguarding of a reliable, environmental benign and economically meaningful energy supply is one of the key challenges Ireland is facing towards 2020 and beyond. The country is transforming its energy system from conventional power generation relying on fossil fuel imports towards a sustainable system utilising renewable and domestic sources of supply. The increased number of non-synchronous power generation stipulates the development of energy storage technologies as the amount of electricity supplied to the network has to equal the amount of electricity consumed. With an increased share of renewable generators that produce intermittent power output the utilisation of energy storage technologies for the compensation of fluctuations and peak demand is urgently required.

Power-to-Gas energy storage is a concept able to store surplus energy in the megawatt range by using the existing network infrastructure of gas. The system is linking the inflexible power network with the natural gas grid. The Power-to-Gas concept represents a complete system solution in its ability to store surplus electricity in chemical form. In a first step hydrogen is produced through the process of electrolysation. In a subsequent reaction hydrogen is united with carbon dioxide in order to produce synthetic methane. The synthetic natural gas (SNG) is able to replace fossil gas reserves on a like-for-like basis. The basic process ingredients of water, electricity and carbon dioxide reduce any dependencies on rare material components and promote its universal application in connection with non-synchronous power generators. This thesis highlights the performance characteristics of Power-to-Gas energy storage and examines the potential environmental and economical impacts of the technology for Ireland.