Renewable Energy SJCHS

Energy World energy demands increase every year (especially in China and India)

Renewable energy near Fukashima

Wind Power Wind Power: Wind is used to rotate a magnet that generates electricity by electromagnetic induction; 1.5% of world energy

Wind Power Pros: No emissions, little environmental disturbance, works in many locations Cons: Need steady winds or power can fluctuate (cannot make up more than 20% of nation’s power outputs); noise pollution, affects flying animals, high cost

Wind Turbines

Hydropower Hydropower: Water is stored behind a dam or in a high altitude lake; Water is released, spinning a turbine, making electricity; Water moves into an afterbay; 20% of world energy

Hydropower Pros: High efficiency, long equipment lifetime, flood control, can use afterbay water Cons: High cost, damming a river can affect ecosystem and fish, can flood areas beyond dam

Solar Solar Photovoltaics (PV): Using the sun’s rays to directly generate electricity (no turbine)

Solar Sun’s rays generate electricity which is used to power house or is sent to grid during the day At night, use electricity from the grid

Solar Post Solyndra

Solar Pros: Low emissions, “free” electricity Cons: High cost, low efficiency (especially in cloudy areas)

Solar Solar Hot Water Heaters: Using the sun’s rays to heat hot water instead of using natural gas or electricity

Solar Pros: Low emissions, relatively low cost with rebates, durable Cons: Low efficiency in cloudy areas

Solar Solar Thermal Power Stations: Using the sun’s rays to heat either oil, a gas, or water which will spin a turbine and generate electricity

Solar Pros: Low emissions, “free” power Cons: High cost, low efficiency, large land area

Solar Homes

Geothermal Geothermal: Radioactive decay of material in Earth produces heat; water reservoir near surface is heated and can be used to spin a turbine

Geothermal Pros: Low emissions, waste hot water can be used, relatively low cost Cons: Low efficiency, can only build in areas near plate boundaries or volcanic activity, damage environment, reservoir can be depleted

Geothermal/Solar Ground Source Heat Pump: Due to solar heating, beneath the surface of the temperature is the opposite than the temperature at the surface; can use to heat or cool homes

Geothermal/Solar Pros: Low emissions, “free” power Cons: High cost

Geothermal at home

Cars Gasoline/Diesel Cars- Internal Combustion Engines (ICE): Use a compressed gas mixed with fuel to power car; high emissions, lower cost

Cars Hybrids: Have an electric motor and an ICE; lower emissions and regenerative braking Type 1: Electric motor runs car when stopped/ moving slowly, otherwise ICE runs car

Cars Type 2: Electric motor always runs car; ICE makes electricity that charges the battery for the electric motor

Cars Electric Cars: Electric motor, powered by a battery, runs car; must charge battery using electricity; no emissions and regenerative braking

Cars Hydrogen fuel cells: Use hydrogen as a fuel to generate electricity for an electric motor; only produces water as a waste

Hydrogen Fuel Cells Cars of the Future

Cars Biofuels (Biogas): ICE that are run on fuels that are made from plants Pros: Renewable, low emissions Cons: Can be more corrosive (need specialized engine parts), cost, lower mileage

Palm Oil