The monitoring and assessment of small and medium solar energy plants were ruled out as the existing programs for these tasks are expensive and they are designed to run directly on the installation site, making it necessary to have both a monitoring system, such as data logger, and specialized staff capable of analyzing the monitoring data. To address these problems, this paper presents a framework that allows the development of programs for remote monitoring and automatic evaluation of solar energy plants without using any additional hardware. Software architecture based on separating the software functionalities into several layers and on using a hierarchical model of the plant elements is proposed. This framework allows the integration of different technologies and communication protocols of devices used in solar energy plants. A monitoring and assessing program for several dispersed solar energy installations has been developed as practical example.