Solar radiation falling on photovoltaic (PV) panel surface can be maximized via solar tracking systems, however, in return for infeasible investments. On the other hand, manual and periodic tilt adjustment of PVs can increase energy yield significantly and cost-effectively. Therefore, this study presents a techno-economic analysis of 1 MW PV power plants with manually adjustable tilt mechanisms. Firstly, the optimal tilt angles for fixed and periodically adjusted (monthly, seasonal, and semi-annual) PV systems in locations with different solar characteristics in Turkey are estimated, and then an economic analysis is performed, including a sensitivity analysis. The results show that, manual tilt adjustment provides a remarkable net present value (NPV) increase in Turkey between 12.4 and 14.9% compared to fixed-tilt. The discounted payback period (DPBP) ranges between 9.20 and 12.36 years and can be shortened by 8- 10 months. The internal rate of return (IRR) of 5.4-8.6% can be increased by 0.7-0.9%. (c) 2022 Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).