Chilled Champagne: turning ground into gold with our latest sustainable heating and cooling system

We’re in Champagne but we’re not talking about wine 🍾.

Instead we’re talking about groundwater – pure, natural, and full of potential. That water, quietly living below our feet, will soon be heating and cooling thousands of homes.

In the city of Reims, France, (the unofficial capital city of the Champagne region) our ambitious eco-district project is transforming a former brownfield site into a beacon of sustainable living. And while this innovation is taking root in northern France, its possibilities are just as exciting for the UK.

Spanning 70,000 square metres, the ‘Nouveau Quartier’ eco-district development will house homes, offices, business premises, and even a high school, all powered by a pioneering geothermal energy system. At its core is our innovative ectogrid™ technology – a combination of renewable energy and intelligent design to meet heating, cooling, and hot water needs efficiently and sustainably.

Here’s how it works:

1. Tapping the earth’s energy: groundwater is drawn from just 45 metres below ground, where it remains at a consistent 13°C year-round
2. Smart heat pumps: each building is equipped with its own heat pump that takes the thermal energy and boosts it up to the temperature needed for heating or cooling
3. Balancing: Once used in the system, the water is then re-injected into the natural groundwater system, maintaining environmental balance and ensuring no resource is wasted

The result? More than 70% of the energy used in this district will be coming from renewable sources, reducing emissions while keeping costs stable for residents and businesses. 

Worth a toast, ne c’est pas!?

Across the Channel...

But this isn't just a success story for France.

The UK is no stranger to innovative geothermal projects. At Silvertown, East London, we’re building the largest ambient heating and cooling network in the UK – powered by ectogrid™. This cutting-edge system reduces energy demand by up to 75% while slashing carbon emissions by a planned 88% compared to traditional gas boilers.

ectogrid™ works by connecting buildings into a shared energy loop, balancing heating and cooling needs. Each connected building captures any excess heating or cooling and shares to neighbouring buildings as needed, and by sharing, balancing, and storing energy in rotation, all available energy is used before any ‘new’ energy is added. 

And it’s not the only groundwater project we’re working on, either!

In the heart of London’s Square Mile, Citigen, our hidden power station, taps into the ancient London Aquifer. Using industrial-scale heat pumps, we extract water from 200 metres below the City Streets to deliver zero-carbon heating and cooling.

A £4 million investment in 2021 expanded Citigen’s capacity, recycling waste heat to provide 4MW of extra heating and 2.8MW of cooling for the financial district.

From Champagne Country to the City of London, these projects are more than just infrastructure – they’re a glimpse into how we can reimagine urban life to be more sustainable, efficient, and affordable while also showing how investment and innovation go hand in hand to accelerate the energy transition.

So next time you’re walking through your city, think about what lies below. The future of energy might just be underfoot.