Solar energy is the biggest energy resource on the earth. Latvia environment is very potential for solar usage, but there are many reasons why consumers have skepticism and a perception that the environment in this region is not suitable for solar energy usage. To have broken this stereotype, this study is conducted. The aim of this program is to explore the suitability of Latvian environment with the use of solar collector For the attainment of objective monotype house will be modeled, the house will be equipped with the combined solar heat system, which will be placed in different regions. There are various amounts of sunny days in different regions, as well as diverse average temperature, wherewith the amount of heat differs. For the modeling of building, modeling program model of solar collectors will be used, which is provided for several solar heat systems, inter alias for the calculation of combined solar heat supply system and for the solving of several relevant tasks. After data inputting, program can model locality individualities of solar heat supply system and can consider them while simulating activity of modeled system. Program is simulation program for the thermal solar energy systems. It suits both for determination of hot water use and heating system use. Program is practical tool in order to calculate parameters of solar heat system, and they are figured in graphics. Wherewith results are achieved, after analysis of results it is theoretically possible to clarify suitability of specific system to specific places systems. There are countries which are located in sunny regions and which history of solar energy usage is very longstanding, wherewith also technological achievements are high, yet our contemporary rapid technology development enables to use ever more solar energy in the regions which are not so rich with the solar radiance, for example in Latvia. Interest about the usage of solar energy in Latvia increase – partly it is explicable to unpredictable and essential price rise of fossil firing resources and partly to the desire to invest in technologies which could reduce this rise in price in the future.