European data center developer Green Mountain and German energy firm KMW have inked a long-term anchor tenant agreement for 36MW of capacity at its FRA-Mainz data center campus.

The capacity is expected to be handed over in stages over around 3.5 years. The identity of the anchor tenant was not disclosed.

“This anchor agreement demonstrates the trust global market leaders place in our delivery model and our commitment to truly sustainable, large-scale data center infrastructure,” said Svein Atle Hagaseth, EVP & chief business officer, Green Mountain Global.

The campus was developed as part of a 50/50 joint venture between Green Mountain and KMW. The companies partnered on the joint venture at the beginning of 2023, with construction beginning in October of the same year.

Located on Ingelheimer Aue, next to the KMW power plants, the 25,000 sqm (269,095 sq ft) was topped out back in February. When it reaches full build-out, it’s expected to offer 54MW across three buildings.

According to the companies, the site will be powered by 100 percent renewable energy generated from KMW’s solar and wind portfolio. Emergency backup power will be supplied via gas turbines, replacing traditional diesel backup generation.

KMW has invested in around ten wind farms, two solar farms, a wind-to-hydrogen plant, a CHP plant, a biogas plant, a 330MW peaking plant, a district heating storage tank, and several power plants.

Cooling for the data center will be provided via the nearby Rhine River, and surplus heat from the facility will be fed into the city of Mainz’s district-heating network via heat-pump technology, which serves more than 20,000 households, the Mainz Cathedral, and Mewa Arena.

Green Mountain was originally founded back in 2009. It was acquired by Israeli real estate firm Azrieli Group for $850 million in 2021 from Norwegian real estate firm Smedvig.

The company currently operates three sites in Norway, in Oslo, Rjukan, and Rennesøy. It is also developing further campuses in Kalberg, Gismarvik, Undheim, and Hønefoss.

Green Mountain is also active in the UK market, after acquiring a data center in Romford in 2022.