The transition to low-carbon energy and energy independence of a country play an important role in the sustainable development of its energy sector. Another important issue of sustainable energy development is the cost competitiveness in the generation process; with new renewable energy technologies, a sustainable energy transition to carbon-neutral society is possible. In this article, we present a view of sustainable energy transformation based on a case study of Malta. We have created a simulation of a Maltese electricity system with projected growth and dominance of photovoltaic energy in the electricity market. The study results suggest that a system with a high penetration of photovoltaics has significant advantage over a conventional system using fossil fuels. In particular, in the simulated Maltese system, the total annual cost of energy was reduced threefold, the CO2 emissions were reduced by 40%, and the energy independence of Malta increased by 60%. In the end, the article gives a recommendation for further research into the Maltese energy system.

The world is facing problems that are related to climate change and pollution, which are partially caused by the emission of toxic compounds and CO2, from the combustion of fossil fuels. The natural resource of fossil fuels, have been exploited for many years, such resources have also been depleted dramatically. The above-mentioned facts determine the need to conduct research that will demonstrate the technological and socio-economical possibilities of transforming energy systems and parts of transport systems from fossil fuels to renewable energy. This paper presents the idea of supplying a selected region, 100% with RES, accounting for costs and environmental efficiencies, for the entire energy system. Further, the analysis of the subject indicated a need to conduct research on correlations derived from integrating collective heating, transport systems with high V2G energy storage capacity and power systems, in order to optimize the functioning of the entire energy market. Furthermore, the above considerations suggest that there is a need to propose a new model for electrical systems, different than the one based on the classical concept of producer-recipient. This research was carried out through a combination of quantitative and qualitative methods. The quantitative analysis applied agent-based modelling; A method supported by extensive qualitative research. The conducted research indicates that renewable energy systems demonstrate greater cost and environmental competitiveness, than conventional energy systems. Furthermore, it has been shown that the integration of collective heating and transport systems, with the energy system has a positive impact on the efficiency of the entire system, by reducing primary energy demand and decreasing carbon dioxide emissions. Finally, the conducted research revealed that the reduction of energy demand, has a positive effect on the transformation of a conventional energy system, into a RES system.