IDA SOLVER: a tool for building and energy systems simulation

General continuous simulation of today is a handicraft mastered by a small group of experts. Systematic modelling techniques and supporting tools are beginning to emerge, promising access to advanced simulation also for less experienced users. Several ambitious projects around the world are at different stages of completion (e.g. EKS, SPANK, CLIM2000, SEE, HS1). These projects approach the task from widely different angles and the final products, once available, will offer a rich menu of alternatives. To a certain extent the duplication of effort is desirable, since the state of the art is still in its early stages and several different paths of development deserve to be explored. However, there are some minimum requirements that a truly effective simulation environment must fulfill. As of today, shortcomings in existing solvers still force most users down to the smallest of detail and many of the advantages with high level modelling are thereby lost. In this paper some of these shortcomings and their remedies are discussed, leading to a list of corner stones for a simulation environment solver specification.