In Minnesota, one sculptor uses the water expelled from his home’s geo-thermal system to create large ice sculptures. Roger Hanson started this project in the winter of 2007.
The geo-thermal system was set to take 47˚ water from the ground, borrowed heat for his house, and then discard it into a pond nearby. The waist in this open-looped version of the system was then re-routed to a sprayer operated by a robot. The robot can direct the spray both an azimuth and an elevational direction. The spray is directed at 1/2″ conduits that are tiered 10 feet above one another. The sculpture above is his largest yet at 85 feet across and 63.25 feet high.
To me this project is intriguing in its potential. We tend to require more shelter and thicker walls of higher R-Value in Minnesota just because of our 4-6 months of cold weather. Then we turn around and have 2-4 months of very hot weather where the air conditioning is blasting to abate the 90˚-100˚ heat. To have a natural material that cyclically could build up to be an insulator in the winter months but then melt away to leave a minimal structure in the summer.
These ice sculptures are visually compelling in the height and strength Hanson has been able to accomplish with is home system. Conceptually it is reminiscent of the Blur Project by Diller + Scofidio. Both projects use a computer system to input weather data and adjust the output of water accordingly. It would be interesting to see if this could be tested further. It may be a faster method for ice structures like the Ice Hotel in Sweden to expedite their construction process. It is not a feasible option for locations between the 45˚ latitutes. It would be interesting to find the structural qualities of ice, whether it is a substitute for masonry as a compressional material, or whether the surface quality of water adhering to itself makes it a tensile structure. 
Material Strategies 