 Reliant on fossil fuels (coal, oil, natural gas)  Those will not last forever, need to have a back up plan  Using fossil fuels creates greenhouse gases, which impact climate change  Renewable energy is better for the environment and people

1. Solar 2. Wind 3. Hydroelectric 4. Biomass 5. Geothermal 6. Nuclear

 Most widely used around the globe  Many shapes and sizes of solar panels

 Sun shines on solar panels  Electricity is created and converted for use  Used to power appliances, lights and heat water  Any extra electricity goes into the main power grid for others to use Solar Power Why aren't we using solar power more?

ADVANTAGES  Completely renewable (the sun is always going to shine)  No pollution/gases given off  Very little maintenance (tend to last a long time)  Will save people money in the long run  Easy to install DISADVANTAGES  Expensive to first purchase  Cannot produce electricity on cloudy days or at night

 Earth receives more energy from the sun in an hour than it used in the entire world in one year  It would take less than 1% of the Earth’s land area covered with solar panels to supply all of the world’s electricity needs

 Type of solar energy  Winds are caused by uneven heating of the atmosphere by the sun  Come in many different sizes

 Wind blows causing the wind turbine blades to spin  Turbines convert wind energy into mechanical power  Mechanical power is converted into electricity Wind Energy

ADVANTAGES  No gases or pollution given off  Only take up a small plot of land  Can farm beneath  Remote areas can use wind power to produce electricity DISADVANTAGES  Strength of wind is not constant  Noisy  Not all people want to look at them  Large wind farms are needed to provide communities with electricity

 Wind energy has been around since 200 B.C  United States generates more wind energy than any other country, except China  By 2050, the United States has to potential to:  Avoid 12.3 gigatons of greenhouse gases from being emitted  Save 260 billion gallons of water  80 countries around the world use wind power Japan's New Wind Turbine Design

 Uses the force of running water to produce electricity  Usually stored in dams

 Build a dam with lots of water behind it in the reservoir  Near the bottom of the dam, there is a water intake  Gravity causes the water to go down into the intake  The moving water spins the turbine propellers, which creates energy in the attached generator

ADVANTAGES  Minimal pollution  Reduces greenhouse gas emissions  Running water is free  Rainfall renews the water in the reservoir, so the fuel is almost always there  Low operation and maintenance costs  Reliable and proven technology over time DISADVANTAGES  High investment costs  Dependent on water being available  Can disrupt land and wildlife habitats  Loss or change of fish habitat  Prevent fish from migrating  Can displace local populations

 7% of total energy production  Largest hydroelectric power station in the world is the Three Gorges Dam in China  Has been used to power water mills for thousands of years  Tidal power is another type of hydroelectric energy  Hoover Dam creates enough power to serve 1.3 million people each year in Nevada, California and Arizona

 Uses plant material and animal waste  Examples: wood chips and corn  Can resupply/regrow in a short period of time  Some can be converted into biofuels, which can be used to power cars, tractors and trucks

 Burns biomass in a boiler  Usually hot water or steam boilers  Boiler moves the steam or hot water towards the turbine  Turbine spins and creates electricity in the generator

ADVANTAGES  Better for environment than fossil fuels  Easily available  Reduces landfills  Can be used to create other products  Ethanol and fuels Afterlife of Oil DISADVANTAGES  Initial start up cost is high  Not as efficient as fossil fuels  Unpleasant smell  Releases methane gas into atmosphere

 Has been used by humans for most of our history  Burning wood or other materials for heat and cooking  Currently meets 10% of human energy needs around the world  As of 2012, Brazil and the US were the largest producers of ethanol and biodiesel in the world  Algae can be used for energy  Algae based fuels can be produced 5-10 times faster than many forms of land-based agriculture (corn, soy)

 Heat from the Earth  Range from shallow ground to hot water and hot rock found a few miles beneath the surface

 About 4 feet underground, the temperature stays the same all year around (about 55°F)  Pipes are buried 4 feet and below  System pumps a liquid through the pipes to absorb heat and brings it back to the system  Heat exchanger takes the heat from the liquid and forces it to spin the turbine  Energy is transferred to the generator, which produces electricity How it works

ADVANTAGES  Powered by Earth’s heat, which does not change  Can be used for heating and cooling  Small impact on land  Minimal pollution  Less chance for change in cost because it does not involve fuel DISADVANTAGES  High upfront cost  Can have gas emissions escape from inside Earth  Cannot be easily transported

 Geothermal plants in the Philippines and Iceland contribute around 30% of their electricity production  US is less than 1%  Humans have enjoyed geothermal energy in the form of hot springs for thousands of years  In some parts of Iceland, hot water runs from geothermal power plants under pavement and roads to melt ice

 Produces 11% of the world energy  Uses a small amount of fuel that creates a lot of energy

 Uranium 235 rods are placed in water in the reactor endeavors  Control rods are near the Uranium in case of overheating ▪ Also can control the rate of the reaction  Nuclear fission occurs, splitting the Uranium into smaller atoms and releases energy  Energy is used to heat the water, which spins the turbine creating energy in the generator  Nuclear Power Nuclear Power

ADVANTAGES  Very minimal CO 2 emissions  Technology has been created and modified  High amount of energy with a small amount of fuel DISADVANTAGES  Removal and storage of the radioactive waste produced in the plant  High safety risk (high security standard, but accidents happen)  Uranium (fuel) is a scare resource  Takes years to build a new power plant  Planning, laws, safety

 Every months, the power plant must shut down to remove the spent Uranium rods (radioactive waste)  Being used in over 30 counties around the world  Used to power Mars rovers  Curiosity Rover Curiosity Rover  Curiosity Rover- Nuclear Power Curiosity Rover- Nuclear Power  1 in 5 households in the US are electrically powered by nuclear power