A major dossier on renewable energies

# A major dossier on renewable energies

Renewable energies play a crucial role in the global energy transition. They are sustainable energy sources that can help reduce greenhouse gas emissions and reduce our reliance on fossil fuels. This article explores the distribution of renewable energies, strategies for densifying their use, and effective ways to exploit them.

# Renewable energy distribution

Renewable energies fall into several main categories: solar, wind, hydropower, biomass, and geothermal. Each of these sources has distinct characteristics and specific potentialities depending on the region and climatic conditions.

Solar energy is one of the most widely available sources of renewable energy. Solar technologies include photovoltaic panels, which convert sunlight into electricity, and solar thermal systems, which use the sun's heat to generate electricity or heat water. Sunny countries such as Spain, Australia and the United States have great potential for harnessing solar energy.

Wind energy is harnessed by wind turbines that convert the kinetic energy of the wind into electricity. Coastal regions and windy plains are particularly suitable for wind farms. Countries such as Denmark and Germany have invested heavily in wind energy, achieving high levels of renewable energy generation.

Hydropower is generated by the force of moving water, usually through hydroelectric dams. Rivers and waterfalls are ideal sites for hydroelectric installations. China, Canada and Brazil are among the world leaders in terms of installed hydroelectric capacity.

Biomass, which includes organic materials such as wood, agricultural waste and forest residues, can be converted into energy by direct combustion or by transformation into biofuels. Countries with an abundance of forest and agricultural resources, such as Brazil and the United States, have significant potential for biomass energy.

Geothermal energy uses the Earth's heat to generate electricity or provide heating. Geologically active regions, such as Iceland, New Zealand, and parts of the United States, are particularly suitable for harnessing geothermal energy.

# How can the use of renewable energies be densified?

Increasing the use of renewable energies means increasing the installed capacity and maximising the efficiency of existing systems. Several strategies can be implemented to achieve this goal.

First, investment in research and development (R&D) is crucial. Technological advances can improve the efficiency of solar panels, increase the capacity of wind turbines, and make geothermal systems more cost-effective. For example, perovskite solar cells promise to increase the efficiency of photovoltaic panels at a lower cost than current technologies.

Secondly, optimising the location of facilities is essential. For wind energy, this means placing wind turbines in areas where winds are constant and powerful. For solar energy, it is important to install the panels in regions with high sunlight and to minimize shading. Energy potential maps, which identify the most favourable areas for the installation of these technologies, are valuable tools for planners and decision-makers.

Third, government policies play a crucial role. Financial incentives, such as grants and tax credits, can encourage investment in renewable energy. Supportive regulatory frameworks, such as renewable quota mandates and green certificate markets, can also stimulate the deployment of these technologies.

Fourth, the integration of renewable energies into electricity grids is a major challenge. Grids must be able to handle the variability of renewable energy production. Solutions include the development of energy storage technologies, such as lithium-ion batteries, and improved demand-side management capabilities. Smart grids can also facilitate the integration of renewable energies by optimizing the balance between supply and demand in real time.

# How can renewable energies be used more efficiently?

To harness renewable energy effectively, it is important to overcome several technical and economic challenges. Here are some strategies to maximize the efficiency of these resources.

The first strategy is to improve the efficiency of production technologies. For solar energy, this may include the use of solar trackers that orient the panels to follow the path of the sun, maximizing sunlight absorption. For wind energy, larger wind turbines with longer blades can capture more energy from the wind.

The second strategy is the use of hybrid systems. By combining several renewable energy sources, such as solar and wind, it is possible to compensate for fluctuations in the production of each. For example, when the wind is weak, solar can take over, and vice versa. Hybrid systems can also include energy storage sources, such as batteries or pumped storage systems, to ensure a continuous supply of electricity.

The third strategy is the improvement of energy management. Energy storage technologies play a crucial role in making it possible to store excess production for later use. Lithium-ion batteries, for example, can store the energy produced during periods of low demand and release it during periods of high demand. Energy management systems can also optimize resource use based on production and consumption forecasts.

The fourth strategy is the promotion of energy efficiency. Reducing energy demand through energy efficiency measures can facilitate the integration of renewable energy into the energy system. For example, insulating buildings, using energy-efficient appliances, and adopting energy management practices can reduce energy consumption and increase the share of renewable energy in the energy mix.

Finally, the fifth strategy is public education and awareness. Encouraging consumers to adopt more sustainable behaviours and invest in renewable technologies can accelerate the energy transition. Information campaigns, training programmes, and community initiatives can play an important role in this area.

Renewable energies represent a major opportunity to respond to global environmental and energy challenges. By understanding the distribution of different renewable energy sources, adopting strategies to densify their use, and using these resources efficiently, a successful energy transition can be achieved. This transition requires collaboration between governments, businesses, researchers and consumers to overcome technical and economic barriers and to maximize the benefits of renewable energy.