Ground coupled heat pumps are widely used in North America. However, in 2005, we developed the first open system with wells. We installed three warm and three cold wells (total capacity 1,000 kW). We overcame initial scepticism about the feasibility of such a large project. The client was impressed with our technical, theoretical and practical knowledge, highly efficient planning and project management, and the fact that we were prepared to involved in the actual work on-site.