Renewable energy is energy from renewable, constantly replenished, sources that are freely available in nature, such as the sun (sunlight or solar-thermal), the wind, the tidal power, the rain and hydro-power, the geothermal potential of earth and fuels derived from renewable sources such as biomass and bio-fuels.

Renewable energy sources may constitute one alternative source for generation of electric power as illustrated by power generation supply chain – figure.1.

Figure.1 – Power Generation Supply Chain

UCY – commercialization of e-ject – business project.

The three main areas of Energy Sources, being Nuclear, Fossil Fuels and Renewable Energy Sources (RES), utilize different technological applications to deliver the required output, in the form of alternating electric current (ac), to the power grid.

Utilization and efficiency levels in the different Energy Generation lines (technologies) may vary considerably due to various factors such as technological, morphological-geological, natural-environmental, socio-economical or other. Undoubtedly, shaping the power market towards environmental sustainability requires higher penetration of Renewable Energy Sources over other sources, i.e. fossil-fuels and Nuclear power. To better understand the dynamics of an evolving global energy mix one need to look at historical evidence, current trends and projected scenarios.

Figure.2 shows a historical review of global primal energy, from early years of the industrial development up to the 21st century, illustrating graphically the increase in the consumption of global primary energy and the relative utilization (use) of alternative energy sources. Renewable energy sources are illustrated by the higher layer of energy sources (in orange color).

Figure.2 – Global Primal Energy

Source: e2005 – 2006 – Dr Andreas Poullikkas- Integration of future energy systems [EAC]

Taking a closer look at current projections of electricity production sources we can establish further the current and future trends on relative usage (size) for each technology.

Figure.3 is a continuation of figure.2 showing ‘zoomed’ projections of Power Generation up to year 2050. What is clearly illustrated, is the ‘intended decrease’ in the set of fossil fuels and the ‘intended increase’ in Renewable Energy usage, estimated around 2020.

Figure.3 – Relative Shares of Energy Sources for Power Generation – up to 2050


These projections formulate global objectives, which are specifically supported by global activity and political, technological and economical transformations in the global environment and practices. For example, looking at the transformation of EU energy policy we can clearly establish that amongst main ingredients of future sustainable electric systems are RES, implementations of distributed generation (DG) and zero emission installations (power plants, buildings, transportation, utility power generation etc.) which in turn is based on the development of new sustainable technologies.

These objectives are also clearly reflected in the European Strategic Energy Technology plan summarized in figure 4.

Figure.4 – European Strategic Energy Technology Plan in Year milestones


The way to achieve this ambitious plan, requires the diversification of the energy mix in favor of renewable and low-carbon conversion technologies for electricity and in general for heating and cooling. It is thus important to identify the energy potential in renewable energy sources (see solar energy facts) and incorporate such solutions within Energy Policies at national levels that will facilitate increased penetration of Renewable energy sources in power generation. The EU vision on RES and energy mix, foresees that a structured and optimized generation and distribution network would take consideration of environmental dynamic and RES capacities per location within the EU and neighboring areas of Africa and Middle East. Future power generation and distribution will be implemented though specially designed ‘smart-grids’ as the one shown in Figure.5 below; similar initiatives are undertaken worldwide.

Figure.5 – Future Super Smart Grid


Future generation and distribution networks will utilize energy storage to become more efficient and effective in meeting with energy demand and uninterrupted supply of high quality electrical power (see solar energy storage).

The power market has been shaped through-out the years of technological movement and the transient environmental and other challenges. Power generation is one main area of the global energy needs. In consideration of the global environmental challenges, especially at current times of unprecedented political and socio-economical instability threatening nations worldwide, the need for radical and decisive transformation, in all areas, becomes crucial for achieving ‘global sustainability’; Renewable Energy Sources are undoubtedly an ‘intended solution’ towards securing this objective. (

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