Synergy of green hydrogen and Li-ion battery with electrification in hourly power supply and demand projection to 2050: A case study

Long-term projections of electricity supply and demand on a national scale, especially with hourly frequency, are significantly rare but essential for determining the appropriate sizes of both long-term and short-term energy storage. This is particularly important during the transitional phase of energy systems. This study uses Denmark as a case study to project electricity supply and demand from 2025 to 2050 with hourly frequency in countries with high wind energy potential but low solar energy potential. Various macro and micro scenarios were examined to determine the necessary sizes for long-term and short-term energy storage from 2025 to 2050. In addition to determining the size of energy storage from 2025 to 2050, the findings highlighted two significant points. First, for countries to achieve energy independence and reduce reliance on energy imports, the ratio of annual electricity supply to demand should exceed 1.3, particularly when the share of renewables is significant (considering losses in Power-to-Hydrogen and Hydrogen-to-Power processes). Second, installing residential photovoltaic (PV) panels without batteries has a return on investment (ROI) of 50.15 %. In contrast, the ROI for installing both PV panels and batteries is −5.91 %. Thus, it is more cost-effective for households to install residential PV panels without batteries. • Electrification in heating and mobility considered in an hourly frequency for a year. • The adoption of installing residential solar panels considered. • Dynamic pricing is conducted based on generation cost in different years. • Demand of hydrogen calculated for two conditions (high and moderate supply) • Installing PV panels without battery is more profitable than PV panels with batteries for households.