Renewable Energy Sources

Standard: SEV4e. Describe alternative fuels and their required technology - What are renewable resources? How are alternative energies considered renewable?

What is renewable energy? Energy from sources that is constantly being formed

Major forms of renewable energy Solar Wind Biomass Hydroelectric (Water) Geothermal (heat) Tidal Hydrogen

Solar Energy Energy from the sun

What is the sun? Sun in the center of our solar system Hot ball of plasma and gases Provides energy/light to the planets of our solar system Formed 4.6 billion years ago About  93,000,000 miles from Earth Takes 8.3 minutes for sunlight to reach the earth

What does the sun do for us? Provides energy in the form of light The energy emitted is from nuclear fission reactions This energy travels through space and penetrates the Earth’s atmosphere The sun’s energy powers many of Earths Forces: Wind Photosynthesis (plant growth) Water cycle

How is the sun’s energy used? Direct absorption Earth is heated due to the electromagnetic waves emitted from the sun Aides photosynthesis Provides visible light Creates the seasons on Earth Indirectly Generates electricity using solar cells When cloudy, the sun’s rays can still be damaging to your skin

2 Types of Solar Heating Passive solar heating- uses suns energy to heat something directly Examples: Building being orientated to catch the most of the Sun’s energy through their windows Ancestral Puebloans lived in cliff dwellings and used sun to warm their homes

2 Types of Solar Heating Active Solar Heating: Solar cells are attached to a home to collect the suns energy and then convert it to electricity or heat water About 8% of the United States use this method to heat water

What are solar cells? Also known as photovoltaic cells They are used to convert the sun’s energy into electricity

Wind Power Energy created from the wind

How can we create wind energy? The sun heats Earth unevenly, which causes air masses to flow in the atmosphere We use a wind turbine to turn mechanical energy into electrical energy This is one of the fastest growing energy source in the world

What are wind farms? Large array of turbines in windy areas Benefits: Take up little space Can sell electricity back to electric company Cons: Must have wind! Transporting the electricity from rural areas

Wind power facts Estimated that the windiest places on earth could generate 10x the energy used world wide Wind mills were first developed in China and Persia around 2000 BC A single wind turbine can power up to 500 homes There is enough on shore wind in the US to power the country 10x As of May 2014, 46,000 homes in the US used wind power

Biomass power What is biomass fuel? Any organic material that is used for energy Examples Manure Plant materials Wood Dung Methane Alcohol

How is biomass fuels a renewable resource? Biomass fuel is a major resource in developing countries Biomass can be renewable as long as: The amount used is less than what is needed No harmful effects or pollution is produced

Hydroelectricity Power from moving water Also known as hydroelectric energy Accounts for about 20% of worlds power

How does a hydroelectric power plant work? A dam is built across a river to create a reservoir When the water is released, it passes through a turbine and this creates electricity!

Benefits of hydroelectric power Do not release air pollutants Hydroelectric plants last longer than fossil fuel plants Dams provide flood control, water for drinking and recreation areas

Disadvantages of hydroelectric power The is expensive to build and changes the river flow Can disrupt ecosystems both up and down stream

Geothermal power Energy that is created from within the earth’s crust Normally found near steam vents or underground hot springs More than 60,000 home in the US are heated by geothermal power

How does geothermal power work? A plant is built above a water deposit in the earth’s crust Steam rises through a well to the plant It is driven through a turbine to create electricity Leftover liquid is pumped back into the hot rock

Geothermal heat pumps The ground is always warmer than the air in the winter and cooler than the air in the summer Some homes have a loop of piping that extends underground. This piping circulates fluid underground. Depending on the time of the year, the pipe conducts either heat or cool air into the home.

Tidal and hydrogen power Tidal and Hydrogen power are energy sources that are still in development. Because of this, these sources are known as alternative energy For these sources to become practical, they must be proven to be cost effective and have few harmful effects on the environment.

Tidal power Tides are the movement of water caused by the gravitational forces of the earth, sun and moon. Tides rise and fall twice a day

Tidal dams Work much the same way as a hydroelectric dam When the tide rises, water becomes trapped in a dam It is then released through a turbine back into the ocean

Hydrogen Fuel Hydrogen is the most abundant element on earth When hydrogen is burned it combines with oxygen to produce water vapor Hydrogen gas is produced by splitting hydrogen molecules with electricity Hydrogen fuel can be made from anything that has a high amount of hydrogen (like plants)

The challenge of hydrogen fuel 1. Hydrogen fuel production is not very efficient Requires a lot of energy, is expensive, and currently causes pollution 2. A lot of hydrogen is needed to produce the same amount of energy as a tank of gasoline This means that hydrogen has to be compressed (compacted) We do not have the technology to do this safely yet

Fuel cells Combines hydrogen with oxygen in the air tot produce electricity Water is the byproduct Fuel cells can be fueled by using anything containing hydrogen Examples Natural gas Alcohol Gasoline