“…However, the review presented in this and subsequent sections is synthesized in Section 5 in terms of PtG deployment scale, geographical location, PtG products, power and CO 2 sources, PtG products and sub-processes, energy/material integration, economics and modeling/optimization methodologies. Barton and Gammon (2010) [43] UK; 2050; RE N/R Solar PV, solar thermal, tidal energy, wave energy, on/off-shore wind, biomass, waste, hydroelectricity H 2 for mobility, industry, power, gas grid injection and conversion to other fuels Process N/R; Capacities of 61.4 GW and 107.1 GW for "high renewable share" and "high nuclear share" scenarios, respectively N/A Jacobson et al (2011,(2013)(2014)(2015)(2016)(2017)(2018)) [44][45][46][47][48][49][50][51] California, New York, and Washington states, USA; All USA; World; 2050; 100% RE On/off-shore wind, hydropower, CSP, geothermal, solar PV, tidal, wave H 2 for ground, sea and air transportation; industrial and building heat generation Process and capacity N/R; 70% efficiency N/A Gutiérrez-Martín and Guerrero-Hernández (2012) [52] Spain; 2011-2020; 42% RE Wind, solar thermal, solar PV, hydroelectricity, nuclear H 2 for mobility or power (peak shaving) 53 nos. 50 [58] Spain; Timeline N/R; 31% RE Wind, solar thermal, solar PV, hydroelectricity, nuclear H 2 potentially for heating, power, synthetic fuel production or gas grid injection 300 nos 50 MW AEL (efficiency calculated) N/A Clegg and Mancarella (2015) [59] UK; 2030; 48% RE Wind H 2 and SNG for gas grid injection Process and capacity N/R; 73% efficiency Process N/R; 73% power-to-H 2 and 64% power-to-SNG efficiencies; CO 2 source N/R Qadrdan et al (2015) [60] UK; 2020; RE N/R Wind H 2 for gas grid injection Process N/R;~5-12 GW capacity; 70% efficiency N/A Ahern et al (2015) [61] Republic of Ireland; 2030; RE N/R Wind SNG for transport Process and capacity N/R; 75% efficiency Biological; 80% efficiency; 60% power-to-SNG efficiency; Anaerobic digestion biogas-derived CO 2 Vandewalle et al (2015) [62] Belgium; Timeline N/R; 69-76% RE (wo/w PtG)…”