Three load matching indicators (self-consumption rate, self-sufficiency rate, loss of load probability) and the CO₂ emissions were evaluated for 55 Cypriot households with 3 kWp rooftop photovoltaic (PV) generators. The calculations were performed using 30-minute generation and consumption data from a large scale smart meter project in Cyprus. To investigate the effects of recent advances in local legislation, an analysis for higher PV capacities (5 kWp and 10 kWp) was also performed. The PV generation profiles for 5 kWp and 10 kWp PVs were obtained by scaling the 3 kWp PV generation profiles. The results showed that the self-consumption of the analyzed households varied seasonally, as it was related to their heating and cooling demand. More interestingly, the ratio between the households’ annual electricity generation and demand, formally defined here as generation-to-demand ratio (GTDR), was found to be related to the value ranges of the studied load matching indicators. Hence, on average, households with 3 kWp PV generators annually self-consumed 48.17% and exported 2,415.10 kWh of their PV generation. On the other hand, households with larger PV generators were characterized by a higher GTDR, but lower load matching capabilities. For the cases of 5 kWp and 10 kWp PV generators, the average self-consumption fell to 34.05% and 19.31%, while the exported PV generation was equal to 5,122.47 kWh, and 12,534.90 kWh, respectively. Along with lower load matching capabilities, households that generated more than they consumed were also found to have a lower potential for CO₂ emissions reduction per installed kWp within the boundaries of the building. In this context, the GTDR could be used by stakeholders to characterize buildings, infer possible value ranges of more complex indicators and make evidence based decisions on policy and legislation.

The momentous deployment of photovoltaic (PV) installations in modern times converted schemes utilised to support behind-the-meter systems to compensation mechanisms promoting self-consumption for all prosumer types. Moreover, their incorporation with battery storage systems (BSS) is expected to remove technical counter effects and assist in more self-sufficient prosumer sites. As electricity prices are continuously rising, negatively impacting consumers, we intend for this study to serve as a guideline for residential PV-BSS sizing. Additionally, its objective is to provide an operational and economic evaluation of PV-BSS by considering relevant schemes and concentrating on the most effective parameters. This study contributes to the literature with a holistic methodology for sizing and techno-economically evaluating residential systems in the Mediterranean area that is replicable for any state or consumption class. Simulations addressing PV-BSS performance were exploited with the use of real (high-resolution) data, estimating particular sizing, operational, and techno-economic indicators during the entire system lifetime within the framework of a techno-economic analysis. The simulations calculated the initial expenditure, the yearly revenues from the PV-BSS operation, and the corresponding expenses, contrasting them on a year-to-year basis. The results demonstrate that for the five countries addressed as case studies, PV-BSS sizing is significantly impacted by the supporting scheme regarding maximum financial gains. A likeness amid the ideal power-to-energy ratio (PER) indicator of every addressed state for the examined parameters (electricity price and consumption class) was demonstrated for the full self-consumption scheme, whereas for net billing, intercountry discrepancies and generally higher optimal PER values were observed. Finally, an increase in electricity prices or consumption generally decreases optimal PER; therefore, a recommendation is provided for the avoidance of inessential expenditures in surplus system component sizes.

Battery Energy Storage (BES) technology has a major role to play in the upcoming energy transition, especially when it is coupled with variable Renewable Energy Sources (RES) facilities such as solar photovoltaic (PV) systems. On the other hand, financial compensation and legislative barriers currently rendering storage technology, prevent it to become a profitable and reliable solution for energy system integration. This paper outlines the primary targets of StoRES project towards developing a technical solution for PV systems in conjunction with BES. For this purpose, coupled PV-BES residential storage systems were developed in six countries, aiming at optimizing the utilization of storage towards achieving higher PV penetration. Another focus of this paper is the implementation of a community storage system which was installed in Cyprus. This is connected to the same distribution feeder supplying the local residential pilot systems in order to make a credible comparison between the centralized and distributed storage.