The manuscript compares the thermal efficiency of solar collectors with various types of the active surface. The research was carried out on a specially constructed measuring stand that maintains repeatable and constant conditions for measuring collectors’ thermal parameters. The research results show that a collector's active surface roughening allows for about 12% increase in its thermal efficiency, regardless of whether the collector surface is metallic (raw) or coated with chromium black. The highest increase in thermal efficiency was observed for a collector covered with a chromium oxide plasma-coating, whereby the collector surface was subjected to abrasive blasting. Approximately 19% increase in thermal efficiency was achieved in comparison to the base-collector (copper with a smooth surface – raw surface).