Evaluation of hybrid heating systems with a combination of fossil and renewable energy sources

Abstract

Abstract Natural gas heating systems are traditionally very popular in private sector in Latvia because of their numerous advantages, such as high efficiency, relatively low CO2 emissions, automation possibilities and convenient fuel supply, as well as widely available natural gas distribution network. Household natural gas consumption has remained fairly stable over the last decade and accounted for 11.3% of total natural gas consumption in 2017, however, natural gas consumption may decline in the near future, because of installation of renewable energy powered systems which improve systems’ resilience and reduce expenses on heating and hot water preparation. Curently hybrid gas boilers in combination with solar thermal panels are promoted on the market as the most efficient and environmentally friendly solutions. The main aim of this study is to perform a detailed simulation on hybrid gas systems energy production in Latvian climate and to evaluate potential energy savings. The performed simulation results show that solar thermal panels do not actually reduce the consumption of natural gas in November, December and January, whereas in the summer months solar thermal panels almost entirely provide the needed energy to prepare hot water. Nevertheless, the annual savings for a single family house are minor and the payback time for the installation of hybrid gas/solar systems could exceed 20 years.