41. Integrated Renewable Energy-Based Systems for Reduced Greenhouse Gas Emissions

Efforts to develop systems to mitigate environmental pollution are increasing. Renewable energy resources, e.g., solar, wind, and hydro, provide clean energy with almost no greenhouse gas emissions. However, these forms of energy are intermittent, and the costs of systems utilizing renewable energy for power generation or heating/cooling are often not competitive with conventional systems. Using hybrid systems and recovering waste energy are two ways to enhance the utilization of renewable energy resources. In this chapter, numerous integrated renewable-based energy systems are reviewed, based on a number of previous studies by the present authors. The aims of these systems are to enhance energy management and reduce environmental pollution. The chapter starts with a brief introduction of integrated renewable energy systems and their role in mitigating environmental pollution. The description of some integrated systems for residential and community usage is presented. Moreover, the systems are compared with conventional power generation systems in terms of efficiency and carbon dioxide emission. The results show that although the energy efficiency of the residential photovoltaic-fuel cell system is considerably lower than the conventional power generation systems, they release zero amount of emission into the environment during their operation. Fuel cell-micro gas turbine system integrated with biomass gasification has energy efficiencies around 55 %. This renewable-based energy integrated system produces 741 gram of carbon dioxide per kWh, which is comparable with the emission of fossil power plants.