The company Granolio, plc and its related companies Zdenačka farma d.o.o. and Zdenka – mliječni proizvodi d.o.o., in accordance with their commitment to energy efficiency and the green economy and compliance with the strategic goals of the Republic of Croatia and the European Union, have applied at the invitation of the Agency for Payments in Agriculture, Fisheries and Rural Development to the Tender for implementation of the type of operation 4.2.2. and 4.1.3. Use of renewable energy sources from the Rural Development Program of the Republic of Croatia 2014-2020. The purpose of the tender is to increase the efficient use of energy, and the project of building a photovoltaic power plant at four locations within the Granolio Group in order to enable savings in electricity costs. The total value of the investment by Granolio d.d. and related companies based on the contracts and related contracts necessary for the realization of the investment amounted to 31.19 kn (4.12 milion €), and it was partly financed through business cooperation with the company HEP – ESCO and from its own funds. This final thesis will present the analysis of investment profitability as well as the calculation of energy costs savings during the construction of photovoltaic power plants. It is a total of four solar power plants, as part of the mills PJ mlin Farina in Gornji Draganec, Pj mlin Kopanica in Velika Kopanica, and as part of the dairy cow farm, Zdenačka farma d.o.o. in Veliki Zdenci and within the dairy industry Zdenka – mliječni proizvodi d.o.o. also in Veliki Zdenci. The profitability analysis of the project was calculated using basic and additional methods of capital budgeting. In addition to the profitability of the project, the importance of strategy, strategic planning and making timely decisions with continuous and detailed monitoring of market trends has been proven.