## 1 Introduction
Most activities of the SMEs are in the following fields: trade/repair of vehicles and motorcycles (32%), professional/scientific/technical (10%), transport and storage (10%), construction and manufacturing (10%), and others (38%), see Figure 3.  
In these conditions, SMEs represent one of the biggest potentials of energy saving, not fully exploited at present. The modern technologies available today, regarding the monitoring and control tools of energy consumption, have the potential to save at least 40% of energy consumption. The analyses have highlighted the significant energy savings, available at each point of the consumption chain if energy efficiency measures are implemented. Only one SME can save an amount of electricity equivalent to that of 1000 private houses [8]. In the case of investments, there are hidden costs whose \begin{table}
\begin{tabular}{c c c c} \hline \hline
**SMEs’ Type** & **Share (\%)** & **Employees** & **Annual Turnover (mil. Euro)** \\ \hline Micro & 92.13 & 0–10 & \(\leq\)2 \\ \hline Small & 6.61 & 11–49 & \(\leq\)10 \\ \hline Medium & 1.05 & 50–250 & \(\leq\)50 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Classification of small and medium enterprises (SMEs). Figure 3: The share of SMEs according to the activity field. Figure 2: The number of SMEs, employees, and turnover, in 2015.  
share can be quite high for SMEs. Thus, for the large industrial consumers, energy efficiency measures require investments and resources. Their application could reduce the energy consumption with a certain percent, which is recovered with a very high probability because the energy bill is of thousands of euros. However, the allocation of financial resources is very difficult in the case of the SMEs due to the investments, which should lead to saving energy with a similar percent. Thus, the recovery must do from the benefits of energy saving, this being several hundred euros in most cases. In these conditions, more SMEs cannot allocate financial resources to purchase equipment or services [9; 10]. Another aspect encountered in the case of many SMEs refers to the fact that there is not a relationship between the energy department, which takes care of the operation and maintenance of equipment and installations and the financial department, which pays the energy bills. In this case, there are no bonuses from the management staff to encourage the employees to save energy, this being a fixed component, without paying much attention, in the final cost of the final products, without the energy department to be responsible for it [11]. In addition, it is important to know whether SMEs are showing interest or make certain efforts to apply current management standards or moreover, how many of the SMEs seek to meet the requirements of an integrated management system. Most of the SMEs have implemented the following management systems: Quality Management System (ISO 9001), Environmental Management System (ISO 14001), and Health and Safety Management System (ISO OHSAS 18001) [12]. Regarding the Energy Management System ISO 50001 [13], published in 2018, it does not define the specific performance criteria associated with the SMEs' energy consumption and energy efficiency. Instead, a management model is proposed to influence the development and implementation of energy policy to achieve the targets and action plans, considering both legislation and information from the analysis and management of energy consumption. The standard describes the final target, but not how it can be achieved, and does not allow SMEs to understand clearly its position on the process to achieve this final target. Implementation of the ISO 50001 system alone is not enough for the SMEs, because it is necessary to follow the consumption indicators with the purpose of rational energy utilization, to fulfil the targets of the management system efficiency.