Electric Power Generation | Sources of Power Genetation

The electrical power system is comprised of three principal components: generation, transmission, and distribution. This discussion is centered on the generation aspect, which involves transforming various forms of energy into electrical power. This transformation harnesses energy from a multitude of natural origins.

Energy resources are broadly categorized into two groups: renewable and non-renewable. Predominantly, our current electrical power is derived from non-renewable resources such as coal, oil, and natural gas.

The finite nature of non-renewable resources necessitates judicious utilization and the pursuit of alternatives, namely renewable resources.

Renewable energy sources encompass solar, wind, hydro, tidal, and biomass. These sources are not only eco-friendly but also inexhaustible and readily available. Let’s delve into a deeper understanding of these renewable energy forms.

Different Power sources

Solar Energy System

Solar energy stands out as an excellent substitute for traditional power generation methods. Electricity can be harnessed from sunlight through two primary techniques:

1. Direct Conversion: This method employs photovoltaic (PV) cells, which are essentially composed of silicon. These cells have the capability to convert sunlight directly into electricity. To form a solar panel, numerous PV cells are interconnected in either series or parallel configurations.

2. Indirect Conversion: Alternatively, we can utilize solar thermal technology. This involves the use of mirrors to concentrate sunlight, thereby generating heat. This collected heat is then used to boil water, producing steam at high temperatures. The steam’s force is powerful enough to drive turbines, which in turn generate electricity.

A photovoltaic (PV) cell, commonly known as a solar cell, is an electronic device that converts sunlight directly into electricity through the photovoltaic effect. When light photons hit the PV cell, they excite electrons in the cell's semiconductor material, typically silicon. This excitation creates electron-hole pairs, and the movement of these electrons generates an electric current. The generated current can be used to power electrical devices or stored in batteries for later use. PV cells are the fundamental building blocks of solar panels, which are used in a variety of applications from small-scale residential systems to large solar farms.

Solar energy system

Advantages of solar system:

1. Zero Transmission Cost: For a stand-alone solar energy system, there is no cost associated with transmitting power.
2. Eco-Friendly: The system does not emit pollutants, making it a clean energy source.
3. Low Maintenance: Solar energy systems generally require minimal upkeep.
4. Off-Grid Suitability: It’s an excellent option for isolated areas where grid connection is impractical.

Disadvantages of solar system:

1. High Initial Investment: The upfront cost for setting up a solar energy system can be substantial.
2. Space Intensive: A significant amount of space is needed for large-scale electricity production.
3. Weather Reliant: The efficiency of solar energy systems heavily depends on climatic conditions.
4. Expensive Energy Storage: Storing solar energy in batteries for later use involves high costs.

Wind Energy System

Wind turbines are like the unsung heroes of renewable energy, quietly converting the breeze into electricity. It’s all thanks to the way the atmosphere likes to mix things up, with temperature changes causing the wind to dance around. These turbines catch the wind’s rhythm and spin it into a kind of energy we can use – kinetic energy.

Advantages of Wind Energy Systems:

1.  Wind energy is an unlimited, free, and clean source of energy.
2.  The operating costs are minimal.
3.  Wind power systems can generate electricity in remote locations.

Disadvantages of Wind Energy Systems:

1.  Electricity production is inconsistent and depends on wind conditions.
2.  Large open areas are required for wind turbines.
3.  Wind turbines generate noise.
4.  The construction of wind turbines is costly.
5.  Wind energy systems typically produce lower electricity output compared to other sources.
6.  Wind turbines can pose a threat to birds in flight.

Wind energy system

Hydro Energy System

The power generated from river or ocean water is called hydropower. Hydropower plants operate based on gravitational effects. Water is stored in a dam or reservoir, and when released, its downstream flow creates kinetic energy. This kinetic energy rotates the turbines, generating electricity.

Advantages of Hydro Energy Systems:

1.  Hydropower can be quickly activated to provide electricity on demand.
2.  After electricity generation, the water can be repurposed for irrigation and other uses.
3.  Dams are built to last for many years, ensuring long-term electricity generation.
4.  Operating and maintenance costs are low.
5.  No fuel transportation is necessary.

Disadvantages of Hydro Energy Systems:

1. The initial construction cost of a hydropower plant is high.
2. Hydropower plants are often located in remote, hilly areas, requiring long transmission lines to deliver electricity to populated areas.
3. Building dams can result in the flooding of towns and cities.
4. Hydropower generation is dependent on weather conditions.

Hydro energy system

Coal Energy System

A thermal power plant generates electricity by burning coal in a boiler to produce heat. This heat converts water into high-pressure, high-temperature steam, which flows into a turbine and spins a generator to produce electrical energy.

After passing through the turbine, the steam is cooled in a condenser and then reused in the boiler to generate steam again. The operation of a thermal power plant follows the Rankine cycle.

Advantages of Coal Energy Systems:

1.  Coal is inexpensive.
2.  The initial cost is lower compared to renewable power plants.
3.  It requires less space than a hydroelectric plant.
4.  Thermal power plants can be constructed anywhere since coal can be transported to the plant regardless of its location.
5.  The construction and commissioning of thermal power plants take less time compared to hydroelectric plants.

Disadvantages of Coal Energy Systems:

1.  Coal is a non-renewable energy source.
2.  Operating costs are high and vary with fuel prices.
3.  Coal energy production pollutes the atmosphere with smoke and fumes.
4.  It requires a large amount of water.

Coal energy system

Nuclear Energy System

Nuclear power plants are quite similar to their thermal counterparts in how they operate. In a thermal plant, you’d typically find coal being burned in a boiler to kick off the heat production.

Switch over to a nuclear plant, and it’s uranium that takes center stage in the reactor, stepping in to create the heat. Whether it’s coal or uranium, the end game is the same: turning that heat into the electricity that powers everything from lamps to laptops.

Now, here’s a fun fact: a single kilogram of uranium packs a punch equivalent to what you’d get from setting 4500 tonnes of coal or 2000 tonnes of oil on fire. That’s a whole lot of energy from a little bit of uranium!

Advantages of Nuclear Energy Systems:

1.  Requires less space compared to thermal and hydroelectric power plants.
2.  Can generate a very large amount of electrical energy from a single plant.
3.  Does not emit CO2.
4.  Requires a small quantity of fuel.

Disadvantages of Nuclear Energy Systems:

1.  High initial construction cost.
2.  High operating and maintenance costs.
3.  Produces radioactive waste.
4.  Poses significant risks of radioactivity and potential explosions.

Nuclear energy system

Installed Electric capacity of Bangladesh

Installed capacity data taken from BPDB website