Understanding Renewable Energy Sources

Renewable energy is all about using nature to create power we can use. This process changes different types of energy, such as moving energy, stored energy, heat energy, and energy from machines, into usable electricity.

1. Solar Energy to Electricity:

• Solar panels turn sunlight, known as solar energy, directly into electricity. This happens thanks to something called the photovoltaic effect.
• In 2020, solar energy made up about 3.6% of electricity made around the world, which is around 820 terawatt-hours (TWh) each year.
• Typically, solar panels are pretty good at their job, changing about 15% to 22% of the sunlight they catch into electrical energy. So, if they get sunlight that is around 1000 watts per square meter, they might turn that into about 150 to 220 watts of electricity.

2. Wind Energy to Mechanical and Electrical Energy:

• Wind turbines use the energy from the moving air, called kinetic energy. When the wind blows against the blades of the turbines, they begin to spin, changing that moving energy into mechanical energy.
• Then, this mechanical energy is turned into electrical energy with the help of a generator. In 2021, wind energy produced about 8.4% of the world’s electricity, which is over 1,600 TWh.
• Wind turbines work at different levels of efficiency, called capacity factors, which can be between 30% and 60%. This tells us how much energy they produce compared to their maximum potential.

3. Hydropower:

• Hydropower plants make use of water that is stored high up, using its potential energy. When the water flows down, it spins turbines, turning that potential energy into moving energy, and then into electrical energy.
• In 2020, hydropower contributed around 16% of the total electricity made globally, which is about 4,300 TWh.
• Modern hydropower turbines are very efficient, usually converting over 90% of the water's energy into electricity, making this a great way to generate power.

4. Biomass Energy:

• Biomass energy comes from taking organic material, like plants and waste, and changing it into heat energy through burning. This heat can then be transformed into mechanical energy to produce electricity.
• In 2020, biomass made up about 5% of the global energy supply, or about 1,500 TWh. It's called a renewable resource because we can grow more of it over time.

In short, renewable energy sources change different types of energy—like moving, stored, and heat energy—into electricity. They play an important role in creating a cleaner and more sustainable energy future.