Page 6 - Environmental_Green Technologies

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Even if these energies have been existing for years, they have been requiring a sophisticated technology to
exploit them at a commercial level. The investment in energy research and development experienced an
increase by the oil crises of the 1970s and accelerated since then, with an increase of 1000% of the
consumption. Developing nations produce and consume more renewable energy compared to
industrialized or transitioning countries. European countries have been the fastest growing countries in
renewable energy usage due to support for the expansion of renewable energy sources.

1.2 Sustainable Energy Sources

Sustainable energy sources are those derived from natural resources that are not finite or exhaustible. It is
the alternative to traditional energy, fossil fuels, being less harmful and more sustainable forms of energy.
The several renewable energy sources are the following:

Source: (Shekhani, 2014)

- Bioenergy – Bioenergy is used to define the energy generated from organic matter. It can be classified
into traditional and modern bioenergy. The traditional bioenergy is the one obtained from the biomass that
can be taken from plants, timber, animal waste and traditional charcoal. Biomass can be directly burned
for power generation or heating, or converted into oil or gas substitutes, being liquid biofuels, a renewable
substitute for gasoline. The modern bioenergy technologies include liquid biofuel, bio-refineries and wood
pallet heating systems, among others. Bioenergy can be used in heating, electricity, transport and cooling;
and as mentioned previously it can be used in a solid form, such as burning wood for energy, liquid forms,
like the biofuels and gaseous forms, like biogas. Bioenergy emits carbon dioxide emissions, and the overall
environmental impact and benefits of bioenergy depends on whether energy crops or waste feedstock are
being used (Good Energy, 2019).