Concept
Renewable energy refers to energy obtained from natural sources that have the ability to regenerate or replenish themselves at a faster rate than they are consumed. Sources like sunlight and wind constantly renew themselves, making them abundant and readily available.
In contrast, fossil fuels such as coal, oil, and gas are finite resources that take hundreds of millions of years to form and are not replenished within human timescales. When fossil fuels are burned to generate energy, they release harmful greenhouse gas emissions, particularly carbon dioxide, contributing to climate change.
One of the significant advantages of renewable energy is its lower emissions compared to fossil fuels. Shifting our reliance from fossil fuels, which currently account for the majority of emissions, to renewable energy is crucial in addressing the urgent climate crisis.
Furthermore, renewable energy has become more cost-effective than fossil fuels in many countries. Additionally, the renewable energy sector creates three times more employment opportunities compared to the fossil fuel industry. These factors highlight the economic and environmental benefits of embracing renewable energy.
Common sources of renewable energy
SOLAR ENERGY
Solar energy, the most abundant of all energy resources, can be harnessed even in cloudy weather. The Earth intercepts solar energy at a rate approximately 10,000 times greater than humanity’s energy consumption.
Solar technologies offer a wide range of benefits, including heat, cooling, natural lighting, electricity, and fuel generation. These technologies convert sunlight into electrical energy through either photovoltaic panels or concentrated solar radiation using mirrors.
While solar energy availability varies among countries, direct solar energy can make a significant contribution to the energy mix in every nation.
The cost of manufacturing solar panels has dramatically decreased in the past decade, making them not only affordable but often the most cost-effective form of electricity. Solar panels typically have a lifespan of about 30 years and are available in various shades depending on the manufacturing materials used.
WIND ENERGY
Wind energy is a renewable power source that efficiently captures the kinetic energy of moving air. This is achieved through the use of large wind turbines, which can be situated on land (onshore) or in bodies of water such as seas or freshwater (offshore). Over the past few years, advancements in onshore and offshore wind energy technologies have emerged, aiming to maximize electricity generation. These advancements include the utilization of taller turbines and larger rotor diameters.
Although average wind speeds vary significantly depending on the location, the global technical potential for wind energy surpasses current global electricity production. Consequently, most regions worldwide possess substantial untapped potential to facilitate the extensive implementation of wind energy solutions.
While numerous areas exhibit strong wind speeds, the most favorable locations for generating wind power are occasionally found in remote regions. In this context, offshore wind power stands out as a highly promising avenue, offering vast untapped potential.
GEOTHERMAL ENERGY
Geothermal energy harnesses the abundant thermal energy found within the Earth’s interior. This energy is extracted from geothermal reservoirs through wells or other methods.
Reservoirs that possess natural high temperatures and permeability are known as hydrothermal reservoirs. On the other hand, reservoirs that are hot but require hydraulic stimulation for improved productivity are referred to as enhanced geothermal systems.
Upon reaching the surface, fluids with diverse temperatures can be utilized to generate electricity. The technology employed for electricity generation from hydrothermal reservoirs is well-established and dependable, having been successfully operational for over a century.
HYDROPOWER
Hydropower is a renewable energy source that harnesses the energy of moving water as it flows from higher to lower elevations. This energy can be tapped from both reservoirs and rivers. Reservoir hydropower plants utilize stored water in a reservoir, while run-of-river hydropower plants make use of the natural flow of the river.
Hydropower reservoirs serve multiple purposes, such as providing drinking water, irrigation water, flood and drought control, navigation services, and a reliable energy supply.
Currently, hydropower stands as the largest contributor to renewable energy in the electricity sector. However, its effectiveness depends on consistent rainfall patterns, and it can be vulnerable to the negative effects of climate-induced droughts or ecosystem changes that affect rainfall.
The construction of hydropower infrastructure can have adverse impacts on ecosystems. Consequently, small-scale hydro projects are often considered more environmentally friendly, especially in remote communities.
OCEAN ENERGY
Ocean energy is a renewable source of power that harnesses the kinetic and thermal energy present in seawater, specifically through the utilization of waves or currents, to generate electricity or heat.
Although ocean energy systems are currently in the early stages of development, there is significant progress being made with the exploration of prototype wave and tidal current devices. The theoretical potential of ocean energy far surpasses the current global energy demands, indicating its vast capacity for meeting future energy needs.
BIOENERGY
Bioenergy is derived from a diverse range of organic materials known as biomass, which include wood, charcoal, dung, and other manures used for heat and power generation. Additionally, agricultural crops are utilized to produce liquid biofuels. Primarily found in rural regions, biomass is commonly employed by economically disadvantaged populations in developing nations for cooking, lighting, and space heating.
Contemporary biomass systems encompass dedicated crops or trees, residues from agriculture and forestry, as well as various organic waste streams.
While the combustion of biomass produces greenhouse gas emissions, the levels are comparatively lower than those resulting from burning fossil fuels such as coal, oil, or gas. Nonetheless, the utilization of bioenergy should be limited due to potential adverse environmental consequences associated with large-scale expansion of forest and bioenergy plantations, leading to deforestation and changes in land use.
