Case Study: Financial Returns of a Small Home On-Grid PV System vs. Off-Grid System for Water Heating

This paper discusses the current possibilities for the return on investment in a comprehensive photovoltaic system (small photovoltaic power plant) based on the on-grid principle and an off-grid system of photovoltaic panels designed solely for heating domestic hot water. We highlight the fact that due to current feed-in tariffs and the bureaucratic process of approving new consumer connections to the distribution network, consumers are compelled to use a simple off-grid system of panels instead of an on-grid photovoltaic system. However, this allows them to heat hot water throughout the year, thereby saving costs not only on heating but also indirectly reducing electricity consumption costs. The paper presents precise calculations of profits from the photovoltaic system and cost savings from our proposed system. From the comparison of results, it emerges that although our proposed system is not directly aimed at reducing electricity consumption, it can significantly reduce household electricity consumption.