\section{Conclusion}
The main requirement of the work was to measure the real, reactive and apparent electric power, as well as power factor, and to show the values to the user, preferably, plotted as a quantity over time. It had to utilise the ESP8266 chip and the GL.inet board in the process. The work's requirements were, however, met only partially. The problem was caused by the inability of obtaining most of the sought values from the power measuring integrated circuit, the MAX78615 over the \gls{spi} communication protocol. As a result, only the apparent power could be displayed, subsequently preventing the some requirements relying on the inaccessible data from completion. The product design, programming and problems and their solving process provided the author with invaluable experiences, knowledge and skills for the future.