© 2019 IEEE. This paper describes the design, construction and testing of a low-cost Energy Monitoring System used to remotely monitor the condition of autonomous power generators (i.e. solar panels) for Marine IoT applications. The purpose of the device is to expedite remote troubleshooting, highlight potential problems and identify the need for service/recovery. It consists of a Forward Looking Infrared (FLIR) camera, an 8 megapixel video/stills camera, Raspberry pi Mini-PC, two VE.Direct® to USB interfaces, UHF transceiver, GPS and a power supply. Its method of non-invasive testing involves the transmission of GPS position and time stamped images, as well as infrared images of the Photovoltaic (PV) panels ashore by Slow Scan TV (SSTV). The image is modulated on a UHF carrier wave and received at an internet gateway using a Software Defined Radio (SDR) receiver on a parent buoy. It is then transmitted ashore for demodulation via TCP link across a subsea Ethernet cable. Invasive monitoring is carried out by attaching a USB interface to the Maximum Power Point Tracking (MPPT) Solar Charge Controllers on the buoy. A Linux shell script run on the Mini-PC logs values such as PV Voltage, Battery Voltage, Charge State and Daily Energy Yield from the PV panels. The device aims to reduce costs and downtime, enabling remote decisions to be made, working towards achieving energy continuum.