The Swiss company Vela Solaris develops and distributes the simulation software Polysun worldwide. Polysun Simulation Software provides invaluable support in the analysis, design and calculation of heating and cooling systems using renewable energy. Polysun has been specifically created for solar thermal energy, photovoltaics, heat pumps, geothermal energy, solar cooling as well as combined systems. Polysun is the ideal sales and design tool thanks to professional reports based on facts including a calculation of economic viability. Polysun Simulation Software has been on the market since 1992. Originally developed at the Institute for Solar Technology at the Technical University of Rapperswil (Switzerland), this software has continued setting the industry benchmark ever since. Because of its scientific fundamentals and excellent user-friendliness, thousends of planners, engineers and installers worldwide trust Polysun. Vela Solaris continues to work with universities and the industry in its aim to constantly improve Polysun.