Systems and methods for interconnecting local generation or power monitoring systems to a residential or commercial electric power system so that the connection is made via a direct connection to the power meter socket on the consumer side of the meter. The breaker for the system may be collocated with the interconnection. The system allows for a quick interconnection of the local generation or power monitoring system by inserting an attachment, or shim, underneath the existing standardized meter for simplified power connection, measurement and communications. The attachment may include integrated measurement coils or sensors connected to built-in power management electronics, a control computer, and/or a powerline communications module.