Paulo Kroeff de Souza

PV hydro hybrid systems

The energy systems based on renewable resources face several acceptance difficulties mainly due to high initial costs and to low final incomes. A way to improve the effectiveness of these systems is the use of more than a source of energy, mainly when the employed sources present some type of complementarity. An interesting combination is obtained with the use of hydro and solar energy resources, that it allows to take advantage of the complementarity among two sources and it allows to investigate the storage of energy in water reservoirs and in batteries. The configurations with a bus in cc would assist demands of until 1 kW to 2 kW, while configurations involving a bus in ca evidently would reach larger powers. This article discusses PV hydro hybrid systems, characterizing some configurations, discussing operation strategies, commenting on the effects of the complementarity in time among the energy sources and evaluating that complementarity in the State of Rio Grande do Sul, in the south of Brazil, besides presenting preliminary estimates of costs.

Energetic Complementarity with Hydropower and the Possibility of Storage in Batteries and Water Reservoirs

The complementarity of energy resources used in hybrid systems can open new perspectives for the design of energy systems. Complementarity may be important as a tool for decision makers can sort projects and may be important for an energy system can overcome periods of energy scarcity. This chapter proposes a way to assess the complementarity of energy resources with a dimensionless index and study the effect of different degrees of complementarity on the performance of PV hydro hybrid systems. This chapter also presents some case studies, discussing consequences of complementarity in real systems.

Energy at the Junction of the Rivers Negro and Solimões, Contributors of the Amazon River, in the Brazilian Amazon

The Negro and Solimoes rivers join in front of the Brazilian city of Manaus to form the Amazon River. This “meeting of the waters” is a natural phenomenon of great aesthetic beauty that has been the focus of attention of researchers all over the world in various scientific fields. The waters of the Negro are darker and warmer, while the waters of the Solimoes are lighter and cooler. These waters have very different characteristics and remain without mixing, flowing side by side for several miles. Some reports indicate a temperature gradient between the waters of the order of 6°C, which can be used in conjunction with very high flow rates delivered by the two rivers, with a heat engine operating on a thermodynamic cycle to provide electricity. This review paper identifies this energy resource and presents a preliminary assessment of the potential for power generation. A realistic assessment of the potential points to an available power of about 1 GW. It is clear that further studies are needed to accurately assess the available thermal gradient and its variation over time, to move forward in the design of the power converter, and to establish an appropriate location for a power plant.