Renewable Energy

Video Transcription

Hi, I'm Jensen Morgan. We are going to talk about some great concepts in environmental science. Today's topic is renewable energy. So let's get started.

We are going to talk about renewable energy, its various types, their impacts, and general challenges with renewable energy. Renewable energy comes from sources that, if properly managed, do not run out and can be sustained indefinitely because they replenish in a relatively short amount of time. Renewable energies are considered alternative energy sources because they come from things other than fossil fuels. At the making of this video, approximately 10% of global energy comes from renewable sources. There has been recent growth in renewable energy use due to technology advancements and growing environmental concerns surrounding reliance on fossil fuels.

There are five main types of renewable energy that we are going to talk about. First up, solar or photovoltaic energy-- this is when solar rays are caught and used for heating spaces or water or converted into electricity through the photovoltaic effect. Wind power utilizes wind currents, which are produced by air being heated by the sun, causing it to rise and then sinking as it cools. The wind currents turn massive turbine blades which generate electricity.

Hydroelectric dams, as well as tidal and wave generators, utilize the movement of water to spin turbines and generate electricity. Biomass is a form of energy where biomass materials are burned for heat or electricity. Examples include burning wood for heating and cooking, as well as burning switchgrass, a high yield crop, for energy use or using it to make ethanol.

Ethanol can be used as a fuel, like they do in Brazil, or as a fuel additive, like they do in the US. And it can come from corn, switchgrass, as well as other biomass sources. Alcohol and methane can also be extracted from biomass to be turned into a fuel source. While biomass as a concept does include animals and other organisms, they are not usually used as a renewable energy because it would not be efficient enough.

Our fifth source of renewable energy is geothermal. This is when heated water from below the Earth's surface is captured and the steam is used to generate electricity. As I said before, only 10% of the world's energy currently comes from renewables. And each form of renewable energy, except for geothermal, actually relies on the sun in some way: solar and PV for its direct radiation, wind to create wind currents, hydroelectric to facilitate the water cycle, and biomass to create growth.

Compared to fossil fuels, renewable energy can have significantly less waste. And as a result, it can have relatively low negative impacts on the surrounding ecology and human health. In operation, renewable energies produce little to no greenhouse gas emissions, which means they have less impact on global climate change. Because renewable energies can quickly replenish themselves or are inherently infinite, they are more sustainable than fossil fuels.

Renewable energies do have their challenges, however. It can be difficult to produce and store enough energy for renewables as compared with fossil fuels, because building renewable energy infrastructure can be costly and difficult to transport. Renewable energy supply may not always match demand because weather can be unpredictable, which affects water, wind and sun resources. The supply of renewable energy may be far from their demand, making transport of that electricity difficult.

Now let's have a recap. Today we talked about renewable energy, its various sources and types, its impacts, and its challenges. Well, that's all for this tutorial. I hope these concepts have been helpful and I look forward to next time. Bye.