Introduction to Renewable Energy

1.

Hydro generating plant produces electricity from generators driven by turbines that convert potential energy of falling or fast-flowing water into kinetic energy. Hydroelectric power is the most widely utilized form of renewable energy in the world. Hydroelectric power generation involves storing water at a higher elevation. The water is led downward through large pipes or tunnels (penstocks) to a lower elevation. The difference in these two elevations is known as the head (source of potential energy). The potential energy of falling water is converted to kinetic energy which causes turbines to rotate. The turbines in turn drive generators, which convert the turbines’ mechanical energy into electricity. Transformers are then used to raise the alternating voltage produced by the generators to a higher voltage suitable for long-distance transmission. The structure that houses the turbines and generators, and into which the pipes or penstocks feed, is called the powerhouse.

2.

Solar energy is the radiation from the Sun which can produce heat, cause chemical reactions, or electricity. Sunlight is one of the planet’s most abundant and freely available energy resources. The amount of solar energy that reaches the earth’s surface in one hour is more than the planet’s total energy requirements for a whole year. The total amount of solar energy received on Earth is far more than the world's current and anticipated energy requirements. The amount of solar energy available depends on the time of the day and the season of the year as well as geographical location. If suitably harnessed, solar energy has the potential to satisfy all future energy needs. Solar energy is used majorly in Nigeria for electricity production. In is also used for water heaters and house heating. Solar energy has become increasingly attractive as a renewable energy source as its supply is inexhaustible and nonpolluting. These two characteristics are its advantages over the finite fossil fuels such as coal, petroleum, and natural gas. While solar energy is free, it costs to harness it either directly (thermal energy for heating) or indirectly (electrical energy) for human consumption.

3.

Wind energy produced from the wind is a source of renewable and clean energy. The kinetic energy produced by the turbines that rotate at high-speed relative to the wind’s speed is used to drive generators that produce electricity. Unlike the combustion of fossil fuels (namely coal, petroleum, and natural gas) that are causing global warming, wind energy is becoming increasingly attractive to individuals, businesses, and governments. Wind turbines Two common types of wind turbines are horizontal-axis wind turbines (HAWTs) and the vertical-axis wind turbines (VAWTs). Each HAWT turbine possesses two or three blades, like an airplane propeller. Wind farms are areas where a few wind turbines are grouped together, providing a larger total energy source. Wind farms are most cost-effective in areas with consistent strong winds. These areas may be far away from large population and load centers. This will necessitate the use of power lines and other components of electrical distribution systems to transmit this electricity to consumers. Electricity power storage systems may also be required as wind is usually an intermittent and inconsistent power source.

4.

Biofuel is fuel made from Biomass (plants, algae, or animal waste). Biofuel is a renewable energy source as we can quickly replace these materials, unlike fossil fuels such as oil, coal, and natural gas. Biofuels are popular because they are usually cheaper and better for the environment compared to fossil fuels, especially as oil prices go up and concerns about global warming grow. However, some people worry about the large-scale use of biofuels because of the costs and environmental impact (global warming) of producing them, as well as the potential loss of land that could be used to grow food. So, while biofuels have many benefits, there are also challenges and concerns to consider. Biofuels like wood can be burned directly to produce heat. The heat, in turn, can be used to run generators in a power plant to produce electricity. Several existing power facilities burn grass, wood, or other kinds of biomass. Plant-based biofuels are considered renewable because they come from plants that can be regrown. When these biofuels are burned, they release carbon dioxide, a greenhouse gas, into the atmosphere. However, this carbon dioxide isn't "new." It was initially absorbed from the atmosphere by the plants during their growth through photosynthesis. In photosynthesis, plants take in carbon dioxide and sunlight to produce energy and grow. When the grown plants are later used as biofuels, burning them releases the same carbon dioxide back into the atmosphere, resulting in a cycle. Since no additional carbon dioxide is added to the environment compared to what the plants originally absorbed, biofuels are considered "carbon neutral."

5.

Geothermal energy is a renewable natural resource of heat energy from within Earth that can be captured and harnessed for cooking, bathing, space heating, electrical power generation, and other uses. The total amount of geothermal energy on Earth is more than the world’s current energy requirements, but it can be difficult to harness for electricity production. It is, however, non-polluting as fossil fuels (namely coal, petroleum, and natural gas) which are causing the climate crisis. Although geothermal energy is plentiful, geothermal power is not. The amount of usable energy from geothermal sources varies with depth and by extraction method.

6.

Tidal energy is a form of energy obtained from ocean water due to rise and fall of tides. This energy is used to produce electricity as tides take place every day and every minute in the ocean. It is also a non-polluting and conservating way of producing energy. They are also very predictable and because of this, they are used for the vast production of electricity for many purposes. Tidal energy is harnessed by constructing a dam across a narrow opening to the sea.

7.

Wave energy is a type of renewable energy that takes advantage of the motion of ocean waves to create electricity. Wave power is generated using two main methods:

1. Floating Devices: These include platforms or buoys that move up and down with the waves. The movement drives turbines that produce electricity.
2. Pressure Changes:
• Wave Capture Chambers: These are structures facing the sea where air pressure changes with wave movements, helping to generate power.
• Ocean Floor Pressure: Devices on the ocean floor can capture the pressure changes caused by waves, turning them into electricity.
Wave power is a promising renewable energy source because it harnesses the constant movement of the ocean.