Modular monitoring systems include VMU-C EM modular datalogger for small to medium projects, VMUC-Y EM hardware data aggregator for medium to larger projects, and Em2 Server software for large projects. While VMU-C EM provides relay output, SMS, or email alarms and scalable pulse rate inputs as well as data management of electrical variables from up to 32 energy meters, VMUC-Y EM aggregates data for up to 10 VMU-C EM units. Software aggregates data for up to 100 VMUC-EM units.