Análise econômica de sistemas de geração de eletricidade no modo GD: motor gerador a biogás e painéis fotovoltaicos

Abstract

Due to the need for Brazil to diversify its energy matrix and reduce its dependence on water sources, photovoltaic solar energy sources and biogas have been gaining prominence in the national scenario, mainly because they are clean and inexhaustible sources. The sun is the largest source of energy on the planet and can be used for energy generation, whereas biogas reduces soil and water pollution and produces biofertilizer and electricity, the latter by burning the gas generated by the biodigester. As a result, as of 2012, with the Normative Resolution 482 of ANEEL, it was introduced in the market the possibility of generating energy credits that are injected into the concessionaire's network and subsequently compensated by the consumer. With the increase in distributed generation, a change in the normative resolution is expected, resulting in the need for greater calculations of the economic viability of the projects. Thus, with the aid of Excel and MATLAB software, using the calculations of the Net Present Value (NPV), discounted payback, and levelized cost of energy, the economic viability of two biogas systems and a photovoltaic system implemented in the western region of Paraná was calculated, relating the systems possible regulatory changes. It was concluded that for one of the biogas systems and for the photovoltaic solar system, the alternative 4 could make these investments unfeasible, since the payback time was 24 and 20 years, with an accumulated balance at the end of the systems' useful life of R$ 8,530.70 and R$ 42,200.69 – very low values for high long-term investments. In relation to the levelized cost of energy, the systems presented values of 0.202 R$/kWh and 0.329 R$/kWh, being feasible in relation to the concessionaire's tariffs. The alternative 5 would make investments totally unfeasible, with a final accumulated balance of R$ -178,102.82 and R$ -57,573.99, respectively. For one of the biogas systems, by virtue of participating in the cooperative scheme, all the proposed alternatives are viable, with an accumulated balance in alternative 5 of R$ 1,476,649.16, with a three-year payback time, and a levelized cost of energy of 0.208 R$/kWh. For the simulation of a hybrid system, operating with photovoltaic solar energy and biogas, the return on investment was 15 years in the alternative 0, with a balance of R$ 1,160,220.31. In other alternatives, investment is not feasible, with accumulated balance in alternative 5 of R$ -899,776.69. Therefore, changing the forms of compensation for alternatives 4 and 5 would make the growth of distributed generation in Brazil unfeasible. In addition, with the help of MATLAB, an application that allows user interaction to verify the economic viability of an investment, relating it to the six alternatives and the LCOE, was created.