The Greenhouse effect affects humanity. The International Maritime Organization (IMO), complying with the political framework agreed by most countries of the world, has placed high on its priorities the goal of reducing emissions from ships. The creation of a strong regulatory framework with the application of energy valuation plans and quantitative energy efficiency indicators (SEEMP, DCS, MRV, EEDI, EEOI, ΕΕΥΙ, CII, AER) have made it particularly imperative to take specific measures to reduce fuel consumption and in general energy saving in both new-build and existing ships. In addition, there is the need to significantly reduce the cost of maintenance and operation of the ships in combination with the maintenance of high reliability and availability both from the main and auxiliary engines as well as from the rest of the energy systems of a ship. Based on the above, the need to continuously monitor, record and evaluate the energy consumption and the operational status of a ship in real time at a relatively low cost becomes clear. This will allow the formulation and implementation of targeted energy upgrading measures in both commercial and warship vessels’ recording as well as evaluation of energy consumption and the operational status of a ship in real time at a relatively low cost.