Renewable Energy and Solar Power
Energy is the ability to do work. The energy used to power most tools and machines is called electricity. It is a secondary energy source, which means that it comes from other sources of energy. The energy sources used to generate electricity can be categorized as either nonrenewable or renewable.
This chart shows what our energy is used for...
Nonrenewable energy sources can not be replenished. Once they are used, they are gone. Unfortunately, we use far more nonrenewable energy sources than renewable ones. Renewable energy is obtained from sources that are either unlimited or they can be replenished. There are five main types of renewable energy sources.
The sun is constantly shining down on our planet and providing us with so much free, usable energy. We can use the sun's heat or we can produce electricity with it. The most common use of solar power involves using solar panels to convert sunlight into electricity. This is further discussed in the Solar Panels section of this page.
Here's a quick fact:
Here is a picture of a solar panel...
Another free and usable form of energy on our planet is the movement of wind. The uneven heating of the earth produces wind. As hot and cold air masses collide, wind is created. So, yet again, the sun is responsible for a renewable type of energy. We use a technology called a turbine to collect wind and convert it into electricity.
Take a look at this picture of a wind turbine...
Water power is also referred to as "hydroelectric" power. It can be categorized as either flowing water (like in hydroelectric dams) or tidal (using the ocean's currents or tides). Once again, we use turbines to collect this type of energy and convert it into electricity.
Here's a picture of the famous Hoover Dam...
Take a good look at the word geothermal and you can see two parts to the word geo and thermal. Geo by definition refers to earth/land/soil and thermal means heat. Therefore, geothermal energy is heat obtained from under the earth's surface. We can use this energy source to heat water for our homes by running pipes filled with water underground in areas with geothermal activity. This way, we do not have to use a nonrenewable energy source to heat the water, we use the earth's natural heat instead.
Here's a picture of the steam created by geothermal heat...
Methane is a gas that is flammable, just like propane. The decay of garbage creates a gas called methane that we can collect and use. This gas is typically collected from landfill sites using special collection systems.
Here's a picture taken from inside a landfill...
Solar Power Uses
1. Heat Water - using a solar collector
2. Generate Electricity - using a solar panel
Here's a little tidbit about solar power...did you know that every minute, enough of this energy reaches the world to meet the world's energy demand for one year?
Solar collectors heat water by using a series of tubes containing water. Pumps fill the tubes with cold water and once it is heated to the desired temperature, it is pumped into a holding tank until it is used. The tubes are then filled up again with cold water and the cycle continues.
Everyday that sun shines down on our planet. The sunlight is filled with tiny energy packets called photons. When materials are placed in the sunlight, they typically heat up and get warm. But, a material called silicon has a special reaction that helps create electricity. In the sunlight, silicon releases electrons. The flow of electrons is what we call electricity. Solar Panels are made of silicon and are designed with a positive and a negative layer to direct the electron flow down wires so that we can use the electricity.
Here is a diagram illustrating how a solar panel works:
When you are done with the web quest, check out some of these links...