Economic insights for residential heating and DHW energy services: A comparative analysis with a focus on solar systems integration

Countries are responding to the need to reduce their carbon footprints by adopting new sustainable energy technologies through emerging trends and economic models. One of these trends is the 'Energy-as-a-Service' (EaaS) model, where companies assume responsibility for investment, operation, and maintenance, while consumers benefit from sustainable energy services. This model is typically structured through subscription or leasing agreements. This study aims to analyze the economic impact of integrating solar systems with conventional heating and domestic hot water (DHW) technologies in residential energy services, using a case study in France. By applying financial analysis methods such as Total Annualized Cost (TAC) and Benefit-Cost Ratio (BCR), four technology configurations with two renewable energy inclusion scenarios are evaluated within a EaaS model structured around annual subscription payments. The study provides initial insights into how economic parameters, such as energy tariffs and financial incentives, influence the transition to energy services. Results indicate that the annual service cost varies significantly depending on factors like capital costs, equipment lifespan, interest rates, and energy prices. Additionally, the integration of photovoltaic systems (PV) suggests that the valuation of the business model can vary depending on sales structuring, highlighting the need for a global sensitivity analysis to draw more conclusive insights.