Geothermal Energy from Spanish Mines

A new report produced in Spain highlights how mine shafts close to being shut down could be given a new lease of life as renewable energy production sites from where geothermal energy would be fed to the populations living above them.  The report was put together by a pair of engineers working at the University of Oviedo, in the north of Spain, and appears in the current edition of the Renewable Energy journal.

“One way of making use of low-intensity geothermal energy is to convert mine shafts into geothermal boilers, which could provide heating and hot water for people living nearby”, one of these engineers, Rafael Rodriguez, stated in comments made to the publication Science Daily.

Renewable Geothermal Energy

Spain is alive with new photovoltaic technologies, which draw on the country’s widely available solar rays to produce electricity.  Renewable geothermal energy – which draws on the Earth’s natural heat - remains a much less utilised energy source in Spain, however. 

In collaboration with Maria Belarmina Diaz, a university colleague, Rodriguez has come up with a calculation method which deduces how much heat could be drawn from inside a mine on the verge of being shut down, based on measurements undertaken while the mine was still active.

“When the mine is still active one can access the tunnels easily in order to gather data about ventilation and the properties of the rocks, as well as to take samples and design better circuits, and even programme the closure of some sections in order to use them for geothermal energy production”, Rodriguez explained.  He added that while this mine could still act as a source of geothermal energy provision once closed down, the scope of measurements that could be taken and the extent of changes that could be made were both severely limited.

The mine shaft covered by the new geothermal energy study is two kilometres in length.  Here, rocks just half a kilometre below ground have a temperature of approximately 30 degrees centigrade – a temperature found at similar subterranean locations around the world.

Benefits of Geothermal Energy

Among the benefits of geothermal energy when compared to other, older forms of energy provision like industrial fossil fuel incineration - as well as newer energy technologies like wind and solar - are the following:

• Carbon dioxide emissions are lowered
• Geothermal energy is not restricted by weather pattern variations (i.e. cloudier/sunnier days for solar, gustier/calmer days for wind)
• Since the facilities are constructed underground, the aesthetics of the land above are not interrupted by large building sites, etc
• Geothermal energy is considered a long-term, profitable scheme

Among its applications, meanwhile, are heating house and office buildings alike, as well as fish farms, swimming pools and alternative sites.

See also:

New Geothermal Energy Technology Development