Accordingly, the European Union considers as a priority the increase in energy efficiency and energy production through renewable sources (Portuguese Energy and Climate Plan (PECP--PNAC in Portuguese)) [10]. The interest in these issues has developed across all economic sectors, not only because it results in reduced production costs but also because it has a positive impact on environmental sustainability by reducing externalities. Concerning final energy consumption, the industrial sector is the second biggest consumer and a major contributor to greenhouse gas emissions. Some publications have studied the effectiveness of European policies, but they generally focus on a macro perspective [8; 11]. Few [12; 13; 14] present case studies in specific industries, particularly in intensive energy ones, such as the ceramic industry. In this context, its higher consumption forces it to find solutions. The industrial sector in Portugal consumes 30% of total national energy consumption [15; 16] and is one of the sectors that most seek energy efficiency. The Portuguese Intensive Energy Consumption Management System (IECMS--SGCIE in Portuguese) is especially dedicated to industry, and it is under the operational management of ADENE (Portuguese Energy Agency). This program is operated at energy-intensive installations and realizes periodic energetic audits to analyze the use of energy in these facilities and to suggest measures to increase energy efficiency in the audited installations. In particular, the ceramic industry is highly energy-demanding, which makes this industry a key point for Portugal to achieve the objectives set out in the 2030 PNEC. Having in mind the challenge posed by the company, the specific main aim of this study was to analyze the fulfillment of the settled goals in the Energy Consumption Rationalization Agreement (ARCE, in Portuguese) agreed upon between a Portuguese ceramic company and the ADENE. This study aimed to improve the company's energy efficiency, with a particular focus on increasing product quality, reducing retouching, and avoiding energy waste. Moreover, the feasibility of installing renewable energy production was studied, particularly solar and wind energy sources. This was conducted with the aim of considering renewable energy sources as the most affordable method to reduce energy costs and eliminate the use of fossil fuels, which have severe environmental impacts [14]. This case study provides a practical demonstration of how mandatory European policies and regulations of member states can help enterprises improve their energy efficiency. It also highlights the need to evaluate renewable energy constraints and not adopt them as a panacea. Therefore, the company's environmental sustainability can be promoted, as well as this case study can enhance other ceramic facilities to adopt similar sustainable measures. For that, Section 2 characterizes the ceramic industry and its energy needs. Section 3 presents the materials and methods, and the results are presented in Section 4. In its turn, the analysis of the implementation of energy efficiency measures from the 2018 audit is made in Section 5, and the suggested measures to reduce energy consumption and/or energy costs are presented in Section 6. Finally, the conclusions and final considerations, research limitations, and future studies and recommendations will be presented.