Passive Solar Energy

Uses solar radiation to maintain a comfortable temp in the building without electrical aid South-facing windows, which

absorb maximum sunlight Skylights Trees planted on sides as

insulation/channeling wind currents for temperature control

Water wall/thermal mass wall Heat collects throughout the day

in the core of the walls and floors As temps begin to drop, heat is

re-released to achieve equilibrium

Passive Solar Advantages vs. Disadvantages

Advantages Nondepletable resource After initial investment, no cost to harvest

energy Disadvantages/Waste products

Production produces waste products Geographically limited High initial costs

Solid Biomass

Biomass is any organic matter that can be used as an energy source

-ie. wood, crops, seaweed, animal wastes

Burn it, heats water, creates steam, turns turbines, generates electricity

Solid Biomass Advantages vs. Disadvantages

Advantages Potentially renewable Eliminates waste from environment Available to everyone Can be carbon neutral

Disadvantages/waste products Deforestation Erosion; deprives soil of nutrients Air pollution (carbon dioxide, nitrogen, sulfur,

particulate matter) Requires a lot of land

Ethanol

Usually made from corn or sugar cane

Corn or sugar cane is mashed up, enzymes and yeast are added-fermentation takes place where the sugar becomes ethanol and CO2

Mixture of ethanol and CO2 goes to the distillation columns where the ethanol is separated and is blended with gasoline

Ethanol Advantages vs. Disadvantages

Advantages Potentially renewable Domestically produced Lower emissions than fossil fuels

Disadvantages/waste products Releases carbon dioxide Uses lots of land to grow crops Higher food costs Lower gas mileage

Hydroelectric

Water builds behind dam, falling water pushes turbine which transforms into electricity

Hydroelectric Advantages vs. Disadvantages

Advantages Nondepletable resource Low cost to run Flood control Recreation No pollutants/waste released except for the production

Disadvantages/waste produced Limited to rivers High construction costs Loss of habitat, Disrupts flow of water Reduces nutrients downstream since it builds up behind dam Disrupts spawning patterns of fish

Tidal/Wave Energy

Turbines are placed in areas that have high tidal movements

Tides move the turbines that generate electricity Works in both

directions

Tidal/Wave Advantages vs. disadvantages

Advantages Nondepletable resource After initial investment, no cost to harvest energy Tides are predictable and steady No pollutants/waste released except for the production

Disadvantages/wastes produced High initial costs Geographically limited Can harm marine life and affect migration patterns Corrosion

Active Solar

Solar water heating systems A nonfreezing liquid is circulated by an electric pump

through a closed loop of pipes Circulating liquid moves from a water storage tank to

a solar collector on the roof, where it is heated and back to the tank, transferring the heat to water

Photovoltaic systems (solar panels) Solar panels convert sunlight

into direct current (DC). An inverter converts DC into alternating current (AC) which supplies electricity

Active Solar Advantages vs. Disadvantages

Advantages Nondepletable resource After initial investment, no cost to harvest energy Solar panels can provide the grid with excess energy Once the panels are made, emission free

Disadvantages/waste products Manufacturing materials requires high input of

metals and water No plan in place to recycle solar panels Geographically limited High initial costs

Geothermal

A cold liquid (usually water) is pumped down into the earth where it is heated and returned to the surface; the pressurized steam turns the turbines to generate electricity

Geothermal Advantages vs. Disadvantages

Advantages Nondepletable resource After initial investment, no cost to harvest

energy

Disadvantages/waste produced Geographically limited Can emit hazardous gases and steam (carbon

dioxide, hydrogen sulfide) Cannot be transported High installation costs

Wind

Wind turns the turbine blades, which spin a shaft, which connects to the generator and makes electricity

Wind Advantages vs. Disadvantages

Advantages Nondepletable resource After initial investment, no cost to harvest

energy Once turbines are made, emission free

Disadvantages/waste produced Turbine noise Deaths of birds and bats Geographically limited Aesthetically displeasing to some Initial costs are high

Hydrogen Fuel Cells

Hydrogen gas enters the cells, which strips electrons off of hydrogen

Oxygen molecules are split

Ionized hydrogen is positively charged which causes it to bind to oxygen to create water

Hydrogen Fuel Cells Advantages vs. Disadvantages

Advantages Highly efficient Only byproduct is water

Disadvantages/waste produced Expensive and bulky Transportation and storage of hydrogen is

difficult