Warm up

How do you think renewable

energy is different than

nonrenewable energy?

Renewable Energy

SEV4 Resource allocation and

use

Renewable Energy

●Sources that are constantly being formedoSolar

oWind

oMoving water

oEarth’s heat

Solar Energy

●Already used oWater cycle

oPhotosynthesis

oWind

oSunshine warming a room

oSolar cells

Passive Solar Heating(no moving parts)

●Use sun to heat something directly

●Northern hemisphere homesoLarge, south facing windows absorb heat in

winter

oOverhangs block sunlight in the summer

oInsulation and air flow are important

Active Solar Heating(moving parts)

●Sun’s energy is gathered to heat a building or

water

oSolar water heaters

Water heated on roof

Hot water used to heat water supply

Solar Panels

●Photovoltaic cells

oNo moving parts, no pollution (PRO)

oNeed many cells to produce decent

yields (CON)

Wind Power

●Air is heated unevenly --> wind

●Wind power --> Electrical energy

●Fast growing resource

●3 months to build a windmill

Wind Farms

●280,000 homes in CA powered by wind

●Take up little spaceoFarmers add windmills to farm

oSell power to cities

Currently Underused

●Windiest areas on earth could generate

10x energy used worldwide.

●Transportation of energy is challenging

●Wind farms may make hydrogen from

water in the future. Hydrogen used as fuel.

Biomass

●Plant material, manure, other organic

matter used as fuel

●ChallengesoTrees – renewable, but must be managed

oBurning wood or manure – air pollution

Methane

●Decomposition --> methane (CH4)

●Can be burned for heat or electricityoChina – 6 million homes use methane for

heating/cooking

oEngland – Methane from cow manure as fuel

for electricity

oUSA – electricity from methane generated by

landfills

Alcohol

●Ethanol – fermenting fruit or agricultural

waste

●Gasoholomix of gasoline and ethanol

oProduces less pollution when burned

●Requires more fossil fuel input than it yields

Hydroelectricity

●Produced from moving water

●20% of world’s electricity

●How it worksoReservoir holds water

oWater turns turbines/generator

oGenerator turns movement into electricity

Benefits of Hydroelectricity

●Expensive to build but cheap to operate

●No air pollution

●Last longer

●Flood control

●Water for drinking, agriculture, industry,

and recreation

Disadvantages of Hydroelectricity

●Disrupts river flowoEcosystems flooded behind dam

oRiver flow diminished below dam

●Displaces people

●Farmland downstream less productive

●Decay in reservoir --> greenhouse gases

Modern Hydroelectricity

●No new dams in the USA

●Brazil, India, and China still building large

dams

●Micro-hydropower

Geothermal Energy

●From the heat in earth’s crust

●Use water or steam to turn turbines

●The Geysers in CA powers 1.7 million

homes

●Philippines, Iceland, New Zealand, Japan,

Mexico, and Italy

●Renewable, but must be managed

Geothermal Heat Pumps

●Heat and cool homes

●Temp underground is constant

●Loop of fluid in a pipe underground and

into house

Warm up

●What is the difference between

renewable energy and

alternative energy?

Alternative energy

●Still in development

●Some renewable energy was once

alternative energy.

●Gov’t investments are vital to

development.

Tidal power

●BenefitsoTides happen 2x a day

oGenerates electricity

like hydroelectric dams

●DrawbacksoExpensive

oFew suitable locations

Ocean Thermal Energy Conversion

(OTEC)●Benefits

oCold and warm ocean

water are available at

different depths

oCold water boils at low

temp in vacuum

chamber

oSteam can turn a

turbine

●DrawbacksoNot cost effective

oUses 1/3 of the energy

it produces

oEnvironmental effects

unknown

Hydrogen

●BenefitsoAbundant

oNo air pollutants when

burned

o(plants may produce it)

●DrawbacksoGenerating it uses

energy, money, and

makes pollution

oExplosive and

dangerous

Fuel Cells

●Produce electricity chemically

●Combine H2 and O2 and electricity is

produced.

●Water is only byproduct

Energy Efficiency

●What you get out vs. what you put in

●%Energy efficiency =

●Much energy is wasted

Useful energy out

Energy

in

x 100

Efficient Transportation

●Public transportation

●Hybrid carsoEfficient gasoline engine

oElectric engine

oAerodynamic

Cogeneration

●Production of 2 useful forms of energy

from 1 fuel source

●Use waste heat from a furnace to turn a

turbine

Energy Conservation

●Saving energyoUse energy efficient devices

oWasting less energy

Energy Conservation Poster

Create a poster that includes…an energy conservation method around the homea slogan to convey that messagea picture that supports your messagean explanation of why this method saves energy

This will count as a formative grade

Cities and Towns

●Osage, IAo3,600 people saved $1 million/year

Sealed doors and windows

New efficient furnaces

Insulated water heaters

oBusinesses moved to the area

oUnemployment is down

Around the Home

●Spend $1,500/year on energy costs

●Much is wastedoInsulation

oEfficient windows

oWeather stripping

oWash clothes in cold water