Renewable Energy Resources Solar Wind Hydropower Biomass

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 energy equivalent 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 needed  Cheap 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 pollutants  No electricity generated at night  They 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 ( kW) Village Power Hybrid Systems Distributed Power KidWind Project |

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  Cheap  Abundant  Simple  Some noise pollution  Metal blades interfere with TV & radio reception  Aesthetic pollution  Can 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 gases  Domestic 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 biomass origin  These materials are used to produce biofuels, such as ethanol

Biomass Energy

Biomass Pros & Cons  Burning biomass gets rid of solid waste  Creates energy  Creates new markets for crops  Abundant  Releases CO 2 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