| Abstract [eng] |
In Master’s final project, usage technologies of excess energy of solar power plant are discussed. These technologies are divided into sale of excess electrical energy and usage of excess electrical energy for thermal energy production (thermal heat storage). In the final project, 4 000 m2 manufacturing building in Kaunas is chosen as an object. According to the annual electricity needs, the power of solar PV plant is selected. The amount of produced electrical energy of solar power plant is calculated by assessing: solar irradiance in the building area, mounting angle of solar modules and efficiency of both solar modules and inverter. According to monthly electrical energy consumption, excess energy is calculated. This excess energy is used in two ways – it is sold to the power grid or used to store heat in thermal energy storage. An economic evaluation is made for both technologies: according to chosen financial structure the discount rate is calculated, according to technology, cash flow (CF), discounted cash flow, net present value (NPV), benefit and cost ratio (B/C), the internal rate of return (IRR), payback period and discounted cash flow payback time are calculated. In accordance with selected indicators and their changes, sensitivity analysis is made to determine changes in economic results. According to undertaken economic analysis, the conclusion of most efficient way to use excess energy of solar power plant is made. Based on the results of economic analysis, marginal parameters values are calculated. These marginal parameters show to which extent they can be changed so project would be cost-effective (NPV=0). |
