seaWergie, District heating and Cooling networks in Monaco

District heating and Cooling networks in Monaco

SMEG has been in charge of DHC networks in the Principality of Monaco since 1897, in addition to having electricity and gas concessions.


SeaWergie, one of the best examples of Monaco’s sustainable development policy

The energy production plant is connected to the waste treatment plant and to an underground seawater pumping station built into the Fontvielle seawall. The Energy is supplied through insulated networks installed beneath the road reaching the connected buildings.

This CHP plant (combined heat and power plan) enables to recycle energy from waste in three ways, which is called the trigeneration principle  :

  • Electricity, partly reinjected into the grid
  • Hot water, supplied through two heating networks to heat buildings and produce domestic hot water. Regarding heating production, it saves 6000 tons of CO2 emissions every year.
  • Cooling water, supplied through a cooling network to cool service sector buildings, homes and factories.


Thanks to trigeneration, Monaco CHP plant is able to recycle energy from waste into cooling water for the city. This is particularly relevant in summer when both waste quantity and cooling demand are high. This has two main benefits : to reduce electricity consumption and supply energy recovered from local waste.

Since 2013 a new seawater pumping station has been pumping at a depth of 110 metres and enabling to cool in a more sustainable and ecological way :

  • Avoiding 100 000 m3 of fresh water consumption every year;
  • Improving chillers’ energy efficiency
  • Removing the risk of legionella


DHC networks are well adapted to high density cities with buildings such as Monaco. They simplify architectural design avoiding namely rooftops or chimneys installation.

DHC’s are far less noisy than independent building energy production units such as chillers, boilers, or rooftop fans.

DHC’s offer a steady supply of energy thanks to periodic maintenance, and a monitoring system capable of calling a 24/7 on-call duty team.  

seaWergie uses various sources of energy mainly from local, renewable and waste recovery. This contributes to Monaco’s energy transition and to its sustainable development..

How it works

Heating and cooling water are produced in the CHP plant and then supplied through DHC networks to the delivery substations.

Pipes are installed below the streets, mostly in accessible utility corridors, carrying hot and cold water to the connected buildings.

Every building connected to the networks is equipped with a heating and/or cooling delivery substation. It contains an exchanger which enable the transfer of energy from the networks to the buildings providing heating, domestic hot water and cooling.


seaWergie operates as a large central heating system for a building complex or a district. It offers comfort and a steady supply for users while respecting the environment.  DHC networks are a great tool to successfully face the challenge of the energy transition.

Seawater pumping station

Seawater pumping station

Seawater pumping station

Seawater pumping station

Monitoring screen of production and distribution

Monitoring screen of production and distribution

Absorption chiller

Absorption chiller

A few figures

  •  1 ten-floor energy production plant integrated into the city centre with 3 kilometres of networks supplying the west of Monaco.
  •   95% of annual heating energy produced from steam ( recovered from waste )
  •  30% of annual cooling energy produced from steam ( recovered from waste )
  •  1 seawater pumping station pumping water 800m from the coastline at a depth of - 110m
  •  17,500 kW : heating capacity installed
  •  19,100 kW : cooling capacity installed
  •  38,000 kW : seawater cooling capacity


* The heat produced from fossil fuels, is offset through the carbon neutral ECO2 gas offer, and through Prince Albert II Foundation in the case of fuel oil. It results in 0g CO2/kWh compared to the French district heating networks average of 126 g CO2/kWh (2016 figures)





  • 57 heating/cooling delivery substations in 33 connected buildings
  • 30 hectares served by the DHC networks
  • 21 GWh:  heat delivered in 2017
  • 6,000 of CO2 avoided every year regarding heat production
  • 20g CO2/kWh*: CO2 content of heating energy
  • Equivalent to 2,100 housing units served by DHC networks
  • 33 GWh: Cooling energy delivered in 2017
  • 0 grammes/kWh**: CO2 content of cooling energy



** Cooling production: Electricity guaranteed from renewable sources through our EGEO offer. Steam provided by the waste treatment plant.