Title: Storage via power-to-gas in future energy systems - The need for synthetic fuel storage in systems with high shares of intermittent renewables.


Rising global temperature concerns drive unprecedented changes in the electrical power system like the massive deployment of solar PV and wind turbines. Such large-scale deployment of solar PV and wind turbines requires flexibility in the electrical power system, like long-term storage via power-to-gas (P2G), for it to be operated reliably.

This dissertation studies the need for such energy storage via power-to-gas in future energy systems dominated by solar PV and wind turbines, together with the operational impact of power-to-gas on the integrated electric power and natural gas systems. This overall goal is split in different sub-objectives: (i) Assessment of the value of electricity storage for an investor in a given electricity market. (ii) Identification of the circumstances which require electricity storage via P2G to justify the need for investing in P2G conversion. (iii) Once P2G would be installed, evaluation of the impact of such P2G units on the operation of both the electrical power and natural gas systems.

Portfolio optimization studies confirmed that investments in P2G are triggered by a requirement for large energy storage capacities which is typically related to long-term seasonal storage of surplus renewable generation. High shares of renewable generation could be installed as a consequence of an imposed renewable target (above 70%), or when high CO2 emission prices would occur (1000€/ton and above) in combination with an absence of CO2 sequestration possibility. Once P2G is installed, it can also be used for short-term storage cycles and deliver auxiliary services to the electrical power grid.

Short-term operational results indicate that the current Belgian gas network contains ample amounts of inherent flexibility to accommodate P2G integration in high renewable settings. The network can deal with possibly volatile gas injections from P2G without impacting the normal operation of conventional natural gas producers.