A new line of modular monitoring systems for energy management includes data loggers and aggregators and a software solution. The VMU-C EM data logger system for small to medium projects is a combination of hardware modules whose primary function is to collect data from a network of energy meters and environmental sensors and make this data available to end users. VMUC-Y EM is a hardware data aggregator for medium to larger projects. Its primary function is aggregating data from a network of VMU-C EM data loggers in applications that require support for more than 32 energy meters. The Em2 Server software solution for large projects is provided as a Virtual Machine software appliance to be hosted in either a customer’s facility or on a remote server.