Is dynamic energy sharing really necessary? The case study of collective renewable self-consumers in Croatia

With the recent skyrocketing electricity prices and global energy crisis, investments in household photovoltaic (PV) systems can be seen as a pathway towards low-carbon power systems. As investment on the individual household level with a single owner is a well-established scheme, it is also necessary to involve the apartment buildings and multi-apartment blocks. However, some major challenges, such as the early phase of a regulatory framework and lack of demonstration projects which provide the methodology for joint investments and their profitability, hinder the development of joint PV investments. To overcome these obstacles, the paper models the joint investment in a PV system in the multi-apartment building based on realistic load and PV measurement data of 8 apartments located in Zagreb, Croatia focusing on different dynamic keys for PV production sharing and net-metering approaches. The results show that the 15-\min net metering approach is less profitable compared to the monthly net metering approach resulting in a longer period of investment return for all types of dynamic keys. Moreover, it is shown that dynamics in key changes for energy sharing on monthly basis are sufficient to adequately distribute PV production among investors in both 15-min and monthly net metering.