Using language, symbols and text - U6
ENERGY
Fossil Fuels
Fossil fuels are natural substances made deep within the Earth from the remains of ancient plants and animals. Over time, heat and pressure turned decomposing remains into fuels, which release energy when burned.
Coal, natural gas and oil are the three main fossil fuels.
The type of fossil fuels created depends on the kinds of plants and animals and the amount of heat and pressure.
The energy stored in the fossil fuels originally came from the sun. When we burn fossil fuels we release that stored energy. People all over the world depend on fossil fuels for electricity, heating homes and driving cars etc. Fossil fuels supply about 90% of the worlds energy.
Humans are using fossil fuels 10,000 times faster than they are being made. Because they take millions of years to form, they are non-renewable resources that won’t last forever.
We all use energy every day of our lives.
SOLAR
The sun has produced energy for billions of years. Solar energy is the sun’s rays (solar radiation) that reach the Earth. This energy can be converted into other forms of energy, such as heat and electricity.
The main benefits of solar energy are:
Solar energy systems do not produce air pollutants or carbon-dioxide and
When located on buildings, they have minimal impact on the environment
The amount of sunlight that arrives at the Earth's surface is not constant. It varies depending on location, time of day, time of year and weather conditions.
Because the sun doesn't deliver that much energy to any one place at any one time, a large surface area is required to collect the energy at a useful rate.
FACTS ABOUT WIND POWER
* Wind power can be harnessed (used) in a number of different ways.
For example, windmills create mechanical energy, sails move boats
and wind turbines generate electricity.
* Wind power involves turning energy from the wind into other forms
of useful energy.
* Windmills have been around for a long time, they were used in
Persia (Iran) as far back as 200 B.C.
* Wind energy is clean and renewable.
* Large groups of wind turbines are called wind farms.
* Around 80 different countries use wind power to generate electricity
commercially (as of 2009).
* In 1997, wind power generated only 0.1% of the world’s electricity,
this increased to 1.5% in 2008 and 2.5% in 2010.
* The large blades of wind turbines can interfere with some radar
systems used by weather.
* The tips of large wind turbines can reach heights up to 200m (650ft).
Wind turbines can even be installed offshore on floating structures,
sending the electricity generated back to land with the help of undersea cables stations or air traffic controls, at times being mistaken for planes or various weather patterns.
* Modern wind turbines usually have 3 blades which can reach
speeds at the tip of over 320 kph (200 mph).
WATER
Hydro energy is electricity made using water. Sounds weird right? Especially since it's dangerous to mix the two. The water never comes in contact with the electricity. How it works is, water flowing down a river is used to spin turbines inside a generator. Large rivers with fast flowing water work the best.
Energy can be made, or generated, using solids, gas or liquids as its source of power. So how do you use energy? Energy can be generated to produce light, heat or the movement of objects.
Hydropower is mechanical energy that is generated by using the motion of water caused by gravity. Hydropower is one of the oldest forms of energy and has been used by humans since 4000 BC! By learning how to make a water wheel with a handful of household materials, we too can harness, or capture, different amounts of water to generate our own power.
Hydroelectric dams can be found all over the world, where large amounts of water can be trapped behind a reservoir.
If you've ever stood in a fast–moving stream, under a waterfall, or on the ocean shore as waves come crashing in, then you've felt the power of the water. The energy from moving water can be used to create electricity in several different ways.
