That's a bit of a weird article.
The headline states that
How Europe's disused coal mines are successfully being used
But throughout the text the only site they mention is Gateshead "the UK’s first large-scale network".
There is an entire paragraph titled
Which UK towns are tapping into the energy source?
But all they seem to mention are planned future projects.
The Glasgow Observatory and another project in Cheshire are part of a £31 million (€37 million) investment by the Department for Business, Energy and Industrial Strategy (BEIS). The funds being devoted to this research show the increasing interest the government is taking in this striking form of geothermal energy.
Edit: In Germany's Ruhr reagion they pump out old coal mines to avoid flooding because they fear it would further destabilize the ground the region's cities are built on.