The new H2RES model  is a linear optimization program. The model was developed during the INTERENERGY project  and is being continuously updated by the research group from the Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia.
H2RES consists of three main sets of decision variables. First, capacity expansion on annual basis is considered for each of the technologies. The next set of decision variables consists of hourly scale modelling, and at this level, additions or retirements made in the previous step are considered. The third set of variables includes technologies such as energy storage technologies. These include pumped hydro storage, heat, H2, electricity storage in stationary batteries and EV batteries. Storage levels for each of the mentioned technologies are also modelled in hourly resolution for each year in the planning horizon. Storage capacities in the individual heating systems, hydrogen storage, and stationary electricity storage are optimized. In comparison, the storage capacities of heat storage in district heating, and storage in electric vehicles are fixed during a certain predefined period.
The objective of H2RES is to minimize the (discounted) yearly operation and system costs. Since the model is intended for the development of future energy systems, all the future costs are brought to a net present value. H2RES takes into account the costs of operation, investment, fuel, generator ramping, energy import, and CO2 emissions.
 H2RES, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia, 24th November 2021, https://h2res.org/
 INTERENERGY, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia, 24th November 2021, https://interenergy.wp.fsb.hr/