© 2005 Martin Sammtleben, All Rights Reserved.
The building is a cooling-unit – note the pretty icicles!
Here’s another nice shot taken on the site.
For more information please, refer to the website of Reykjavík Energy. They also publish an illustrated brochure (PDF 1.7 MB) that provides plenty of information on technical details, history and the geology of the area.

Tap or click the zoom icon in the bottom right corner of the picture to switch between in-page and fullscreen view