Green hydrogen production potential in New Zealand cities: A bottom-up geospatial approach

• New tool to assess urban renewable energy and green hydrogen production potential. • Significant rooftop photovoltaic potential identified across New Zealand cities. • High hydrogen potential from residential excess solar across demand scenarios. • Hydrogen costs remain high without targeted financial incentives or cost reductions. Urban energy planning requires high-resolution data to capture local characteristics often masked in traditional energy system models. This study presents FlexiGIS-H2 , a spatially and temporally explicit modelling tool to assess renewable energy potentials and green hydrogen integration in cities. The model identifies rooftop solar PV generation potential using detailed residential sector categorisation for estimating surplus electricity and hydrogen production potential. Current and future electricity demand are modelled using the residential load simulator (resLoadSIM). Applied to Auckland and Christchurch, New Zealand, FlexiGIS-H2 reveals substantial technical potential for urban green hydrogen production. While local PV could support substantial hydrogen yields, high Levelised Costs of Hydrogen (LCOH) challenge economic viability. However, future cost reductions in capital expenditure (CAPEX) and solar electricity prices, combined with effective carbon pricing, could significantly improve competitiveness, lowering LCOH to USD 1.5–2.8 /kg. With targeted policy support, green hydrogen could become a competitive urban energy option using excess solar generation.