Renewable Energy Resources

SolarWindHydropowerBiomass

Solar Power origin

Originates with the thermonuclear fusion reactions occurring in the sun

Description of solar power

Solar power is energy that is derived from the sun and converted into heat or electricity.

Benefit: The amazing power of the sun!!!

Energy reaching the earth is incredible. By one calculation, 30 days of sunshine Striking the Earth have the energyequivalent of the total of all the planet’s fossil fuels, both used and unused!

Benefits

Mitigates the effects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy.

pollution free, indefinitely sustainable.

Minimal repair neededCheap over the long run

Disadvantges

•Sun does not shine consistently.

•Underlying problem is weighing efficiency against cost.

•Initial costs can be high.

This makes sense!

Argument that sun provides power only during the day is countered by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity.

Active Solar Power

Energy from sun is stored in a “thermal mass”

When needed, heat from thermal mass is then pumped throughout structure

Large-scale Solar Electric Site

Solar collectors in Southern California

Large-scale Solar Electric Site

These facilities use solar power to heat water to form steam. The steam goes to generate electricity just as in fossil fuel or nuclear electric plants.

No release of air pollutantsNo electricity generated at nightThey do work on cloudy days, though.

Passive Solar Power

Works on the principle that hot air rises and cool air sinks (convection)

Solar heats air and it moves through convection through the structure or to thermal mass

Passive Solar Power

Mass wall or “Trombe Wall

Using back wall as “mass”

To rest of house

Solar Power

Benefits– Abundant– No greenhouse

gases, few other pollutants

– Simple, minimal repair needed

– Cheap over the long term

Detriments– Retrofitting needed if structure is not already designed as

passive solar– Has limitations, night, some locations better such as south

rather than north facing slopes– Initial capital outlay can be high

Wind Power

Wind power: Wind power is the conversion of wind energy into a useful form of energy

Mechanical Power Windmills

High torque, low-speed to pump water, grind grain, saw wood

Types of Electricity Generating Wind Turbines

Small (10 kW)• Homes• Farms• Remote Applications

(e.g. water pumping, telecom sites, icemaking)

Large (250 kW - 2+MW)

• Central Station Wind Farms

• Distributed Power

Intermediate (10-250 kW)• Village Power• Hybrid Systems• Distributed

Power

KidWind Project | www.kidwind.org

Electrical Power Windmills

High speed, low torque machines

Will turn themselves off if wind speed exceeds their limits

Will automatically turn to face the best direction to get wind

Effects of windpower

No greenhouse gases

Few other pollutants

CheapAbundantSimple

Some noise pollution

Metal blades interfere with TV & radio reception

Aesthetic pollutionCan kill birds and

bats- but new designs are taking this into account!

Positive Negative

Where is wind power available?

Wind power not highly suited to these areas

Hydropower

Electric Mechanical

What is hydropower?

Flowing water creates energy that can be captured and turned into electricity. Synonym: hydroelectric power.

Origin of hydropower

Hydropower uses water stored in dams to generate energy to turn the turbine of the powerplant

How hydropower works

Negative effects of Hydropower

Can flood the land

displaces people and animals

Causes local climatic changes

Impacted by drought

Loss of species (aquatic & terrestrial)

Loss of normal nutrient flow down river

Lowers water quality of the river

Positive Effects of Hydropower

Available as needed as engineers control how much water flows through the turbine

No greenhouse gasesDomestic source of energy

Fish ladder to allow fish to move upstream without getting killed

What is biomass energy?

is the energy which is contained inside plants and animals.

Type of Biomass

organic matter of all kinds: plants, animals, or waste products from organic sources.

These sorts of energy sources are known as biofuels and typically include wood chips, rotted trees, manure, sewage, mulch, and tree components.

Origin of biomass energy

biomass origin

These materials are used to produce biofuels , such as ethanol

Biomass Energy

Biomass Pros & Cons

Burning biomass gets rid of solid wasteCreates energyCreates new markets for cropsAbundant

Releases CO2 and pollutants

Causes more farmland to be planted with corn, soybeans – taking the land out of food production

Important to have an energy mix

Using more than one form of energy to meet needs is an important way to ensure long-term energy needs will be met

Just as in ecosystem ecology, we find that Diversity = Stability

Depending on only one form of energy leaves nation vulnerable to all sorts of problems