# Development of an Energy-Efficient Smart Socket Based on STM32F103
## 6 Concluding Remarks  
Standby energy waste contributed significantly to the energy consumption of electric appliances in their operating processes. Over the years, great effort has been devoted to reducing the consumption of standby energy targeting at energy efficiency improvement and associated cost saving. The development of smart socket has been found as a desirable solution to address these concerns. However, previously reviewed literature did not find an optimal design for the development of economic easy operating smart sockets.  
In this study, a smart socket system based on STM32F103 microchip was proposed with the highlights, including, but not limited to, easier control, safety design, lower embodied cost, no rewiring required and great performance in standby waste reduction. Findings of this research can be summarized as:  
Figure 11: Current outputs and errors with various AC inputs (slave jacks).  
Figure 10: Current outputs and errors with various AC inputs (host jacks).  
* Experimental testing and scenario analysis indicate that the developed system can fully satisfy the functional requirements and realize the proposed host-slave control mechanism. The response delay is less than 2 s.
* Lifecycle analysis illustrated that the integration of the developed smart socket can contribute to 6.40%, 77.76%, and 38.76% of energy saving for TV, TV receiver box and stereo system respectively. Regarding the economic concern, the assessment results indicated that an investment of 125.60 Chinese yuan on the smart socket resulting in a standby cost saving up to 1725.60 Chinese yuan over 20 years. The investment payback period is within 159 days.
* Precision testing and error analysis were conducted in this research to validate the reliability and stability of the designed system. Results showed that an acceptable error ratio of less than 3.00% appeared in the measurements of voltage and current values. For the monitoring voltage value, there is a random error which might result from the characteristics of electronic elements. In contrast, the errors in measured current values are proportional to the input current values.  
As the fundamental parameters, monitoring voltage and current values play critical roles in control operations, as well as overvoltage and overcurrent protection. Despite the measurement errors of the current system fall within an acceptable range, it is still worth to improve the precision for higher performance system development. Future studies could be focused on precision improvement by employing higher quality electronic components and developing more accurate calibrating algorithms. Moreover, limited by the time frame, LCA was employed to evaluate the economic attractiveness with theoretical analysis established to assess the technical desirable of the developed system. Therefore, it is still worth to conduct further comparisons with existing studies targeting at optimal solutions for the standby waste reduction of electric appliances.  
Conceptualization and methodology, M.M. and B.H.; programming and validation, M.M.; writing--original draft preparation, M.M. and L.L.; writing--review and editing, B.H.; supervision, B.W. and J.C.  
Funding that permitted this research is granted by the Education Department of Jiangsu Province for Outstanding Teaching Teams through the \"Green and Blue\" project and Yangzhou Polytechnic Institute.  
The authors declare no conflict of interest.