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Harnessing the energy in water and waste

At SUEZ, we’re combating climate change by developing innovative solutions to reduce our customers’ greenhouse gas emissions, optimise their energy consumption and encourage the use of high-potential renewables.


Producing sustainable energy

SUEZ improve performances
Improving the energy performance of facilities
Opting for sustainable energy production solutions
Meeting new environmental regulations
Our innovations

Using the energy in wastewater treatment networks to produce ecological heat

Rising energy prices and the application of carbon taxes demand more efficient ways to create energy. Our Degrés Bleus solution offers an economical and ecological way to capture the heat produced in wastewater and re-inject it into heating circuits.

The Degrés Bleus solution combines a heat exchanger with a heat pump. The heat exchanger, comprising a closed-loop piping circuit, conveys the water warmed by the heat generated by the wastewater to the pump, which then transitions it between the wastewater network and the heating circuit. The calories are then multiplied, increasing the water temperature before it becomes usable. Nuisance-free and completely safe, Degrés Bleus can be adapted to both new and existing networks such as in housing units, offices, hospitals, retirement homes and schools.

Swimming pool at Levallois-Perret
By producing green energy, Degrés Bleus reduces greenhouse gas emissions by 50 to 70 per cent compared with a conventional thermal solution.

Reducing CO2 emissions by 300 tonnes annually

Green energy produced by Degrés Bleus offers a 50 to 70 per cent reduction in greenhouse gas emissions when compared with traditional thermal solutions, and conserves natural resources by reducing the consumption of non-renewable energy by 30 to 60 per cent. The solution is currently in use in 13 sites across France, from the Elysée Presidential Palace in Paris to a university campus in Maubeuge, a swimming pool in Annemasse and the Town Hall in Valenciennes.

Energy for cities and water treatment facilities: turning on the biogas tap

Biogas is a powerful source of sustainable green energy. SUEZ’s advanced anaerobic-digestion processes and filtration systems amplify the volume and purity of biomethane – which has all the properties of natural gas – harnessed from wastewater sludge. We’re putting our expertise in the sustainable management of waste to work developing new solutions to increase our biogas output by 30 to 50 per cent by 2020, so that our customers and the environment can reap the rewards.
SUEZ wastewater treatment plant in Strasbourg
“It is the best possible energy equation: green and 100% local production from an inexhaustible source, transported without any trucks or losses in our networks, all as part of a short circuit.”

Olivier Bitz President of Réseau GDS

Boosting the natural gas network

In Strasbourg, France, where SUEZ operates the wastewater treatment station, we’ve teamed up with local natural gas distributor Réseau GDS on an innovative project – BIOVALSAN – to inject biomethane produced from wastewater into the natural gas network. Today, it produces 1.6 million Nm3/year of purified methane for injection into the city’s existing natural gas network, equivalent to the consumption of 5,000 low-consumption housing units.

BIOVALSAN encompasses two-thirds of the CO2 emissions from the La Wantzenau water treatment station – the fourth-largest in France, treating water for one million people. The station now enjoys one of the smallest environmental footprints in France, thanks to the combination of optimised of the sludge treatment and recovery of the biogas as energy in the form of biomethane. Around 7,000 tons of CO2 emissions have been avoided.

This new source of renewable energy has launched the transition towards a new local, sustainable and carbon-sober energy model in Strasbourg. BIOVALSAN was supported by the European Commission’s LIFE+ program because of the example it has set for regional energy transition.

Energy self-sufficiency for treatment plants

At Glenelg Wastewater Treatment Plant in South Australia, SUEZ’s fully automated co-digestion system utilises an on-site anaerobic digester fed with liquid waste such as sugars, alcohols and other organic-rich wastes to boost biogas production. In its first two and a half years of operation, the biogas harvested at Glenelg produced an extra 1,790MW of energy.

Today, electricity generated from biogas meets 75 per cent of the plant’s energy needs. The process also makes good use of organic wastes that would otherwise end up in landfill. .

Transforming biogas into green fuel

Though regulations were amended in 2014 to allow the injection of biomethane from water treatment stations into the natural gas distribution network in France, the network doesn’t cover the whole country. SUEZ’s  BioGNVAL solution offers a viable and efficient alternative.

The BioGNVAL industrial demonstrator, installed on SIAAP’s downstream purification site in Valenton, is the first of its kind in France to reuse the biogas from the treatment of wastewater as liquid biofuel (bioLNG), a renewable energy that is easy to store and transport. This biogas reuse solution consists of purifying the biogas before liquefying it using cryogenic technology that divides its volume by 1,000. The resulting bioLNG (or liquefied biomethane) is made of almost 100 per cent methane.
SUEZ wastewater treatment plant
“In my opinion, this biogas from our purification stations represents a concrete contribution for the regions to the common cause to make the energy transition” 

Belaïde BedreddinePresident of the SIAAP

Reducing CO2 emissions

The BioGNVAL project has demonstrated that we can produce a clean fuel that does not emit any fine particles, makes 50 per cent less noise and cuts CO2 emissions by 90 per cent compared with a diesel engine – all from our wastewater. The BioGNVAL industrial demonstrator can treat almost 120 Nm3/h of biogas to produce one tonne of bioLNG each day, equivalent to two full tanks for a heavy vehicle. Tests have shown that the wastewater produced by 100,000 inhabitants could produce enough bioLNG to fuel 20 buses or 20 trucks.

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