Energy and Environment Nowadays

Presently, energy and the environment are closely related issues throughout the world. The indiscriminate use of fossil fuels has resulted in adverse effects on the environment (i.e, excessive production of greenhouse gases, pollution of underground and superficial waters, soil contamination). The international reserves of crude oil are declining, and some pessimistic references refer to an important detriment in the annual oil availability for 2050. Because of these facts, the necessity to develop novel sources of energy, especially fuels from sustainable sources, is mandatory. Such alternative sources of energy (ie: wind, solar, biomass, hydraulic) are potential renewable sources capable of changing the paradigm of productive activities around the world. In many cases, the energy production processes include resources commonly available or even the use of materials that are considered waste (ie: wastewaters, agriculture residues, urban solid wastes). Despite all the desirable characteristics involved, the processes included in the generation of renewable energy may not only positively impact the environment, but may also cause harm on surrounding areas. However, to our knowledge, relatively few works have been published carrying out this type of environmental cost-benefit analysis.