About Hemos


Economic considerations and environmental restrictions drive the demand for better energy management onboard. HEMOS project aims to redesign the ship heat energy management system with the aid of dynamic optimisation algorithms.


The global shipping sector currently contributes about 2.5–3% to global CO2 emissions. Within the EU, the maritime sector makes up about 14% of greenhouse gas emissions from the transportation industry.  In port areas, ships are one of the largest air polluters (CO2, Sox, NOx, particles). IMO introduced a new Energy Efficiency eXisting ship Index (EEXI) that poses a challenge for ship owners. Significant increases in fuel prices put additional stress on ship owners to find options to reduce energy expenses.


The energy balance in cruise ships is viewed as a steady-state system. Actual energy demand is dynamic. Depending on the ship’s type, about 40–50% of the heat energy is currently disposed to the environment. Most of the lost heat energy is low temperature (< 100 °C), which is more challenging to convert into valuable energy such as electricity.

HEMOS response

Based on consumer prioritisation and demand, the system is designed to be dynamic with the help of smart automation, where heat flow is directed based on heat demand predictions. For example, weather, operational profile, people’s behaviour on the ship and the actual situation on board are considered rather than steady-state conditions. Thus, a full holistic review and optimisation of the heat energy system must be considered and implemented for good efficiency gain.


An estimated 14% increase in the energy efficiency could be reached through reconfiguration of heat energy flow between consumers, producers and new waste heat recovery technology. At the same time, fuel savings and lower emissions will also be achieved. This can be reached by the dynamic optimization of the ship’s energy system as a whole. For example, if LT heat could be utilised for heating potable water, HFO tanks and pools, and in the cold environment for HVAC heating, then HT heat could be used for electricity production. Based on initial estimations, the payback time could be as low as 2 years.

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