This research was aimed at finding the most suitable solar energy absorption system for use in greenhouses. For this purpose, 5five greenhouses were built in Izeh township and each one with area of 10m2. Five separate systems were implemented including common system,, solar water heater, water wall, stone bed and phase-change material. The research was conducted during six months. Technical factors including functional safety, useful life, reliability, ease of maintenance and repairs together with economical and environmental factors were investigated and compared by Duncan’s test and finally, the method of Analytic Hierarchy process (AHP) was used to introduce the best system. The result showed that the solar water heater system has higher cost and energy absorption also lower average time to repair and phase-change material method has the least failure frequency. The analytic hierarchy process (AHP) revealed the water wall as the most appropriate system and then the solar water heater. Although solar water heater consumes less fuel but it has more cost, lower sale services, failure frequency and it has repeating accident rate more than water wall. This method can be in the first place by reducing cost and improving after – sale services. Placing the traditional method in the last rank, shows that it was not suitable and its use should be reassessed.