Upload
marlene-cynthia-perry
View
227
Download
6
Tags:
Embed Size (px)
Citation preview
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