Geologists concerned

Mega heat storage facility in Wildon meets with resistance

The Weitendorf basalt quarry (municipality of Wildon) is to be flooded for the project and turned into a huge reservoir.(Bild: Sepp Pail)

A huge heat storage facility is to be built on the site of a basalt quarry near Wildon in Styria, which could cover a quarter of Graz's district heating requirements from "green" energy sources in future. There is also opposition: critics fear for the natural monument and unique mineral site.

A spectacular energy project is currently being planned in Wildon, south of Graz. The Weitendorf basalt quarry, which is currently still in operation, is to be closed down and converted into a gigantic heat storage facility. Roughly speaking, this is how it will work:

The quarry will be flooded once with water from the Kainach river, turning it into a reservoir for around 1.5 million cubic meters of hot water. The reservoir will be covered and heated to 90 to 95 degrees by surrounding solar thermal collectors. The water is then heated to the 120 degrees required for the district heating network using a biomass heating plant and high-performance heat pump. A pipeline around four kilometers long will feed the water into the network near Mellach.

 Investment volume of  272 million euros
According to the project promoters, a quarter of Graz's district heating requirements could be covered by "green" energy in future. The Styrian entrepreneurs Heimo Ecker-Eckhofen, also owner of the quarry, and Gilbert Frizberg are behind the ambitious project. A year ago, they went public with the project, in which around 272 million euros are to be invested. What is the status today?