Page 5 - Environmental_Green Technologies

5

Chapter 1

Green renewable and alternative

1.1 Renewable and alternative energies – Concept

Wood has been the major source of energy of all the nations’ until the mid-1800s. From the late 1800s
until nowadays, fossil fuels such as coal, natural gas and petroleum have been predominant. Regarding the
renewable energy source methods, the hydropower and solid biomass were the energy sources most used
until the 1900s. Since then, the consumption and production of energy through renewable energies
experimented an increase with new sources such as solar, wind or biofuels.

Source: Arm River Builders, LLC. (2016).

In 1896, for the first time, a Swedish scientist named Svante Arrhenius tallked about the negative effects of
fossil fuel and its contribution to the global warming. Nowadays, the climate situation is a severe issue with
negative prognostics, and it is creating a general shift towards environmental awareness and the source of
climate change, making the citizens aware of the situation. Different organizations and governments are
supporting the shift, considering that renewable energies bring lower emissions, lower fuel prices and the
reduction of pollution compared to fossil fuels. However, even being an alternative to traditional energy
sources, it does not mean it is completely environmentally safe, because in occasions, for instance, it might
have environmental impacts in an indirect form or as a result of the needed manufacturing processes
(IRENA, 2019).

Renewable energy is taken from parts of the planet’s physical structure, renewed by natural means; it is
obtained throughout existing flows of energy and natural processes.

The sustainable energy sources are also called ‘’alternative energies’’, as they present alternatives to the
traditional fossil fuels.The renewable energy sources are part of the group of alternative energy sources,
but not all alternative energy sources are renewable. Alternative sources include all the non-fossil based
processes and sources. Alternative, not renewable sources are for instance, fission power and hydrogen
power. Renewable energy sources are those naturally occurring and replenishing naturally, without
humans’ interaction.