renewable energy
DESCRIPTION
RENEWABLE ENERGY. CH. 12. PASSIVE SOLAR HEATING. BUILDING PLACEMENT, MATERIAL, AND DESIGN ex: LARGE SOUTH-FACING WINDOWS (N. Hemisphere) WITH GOOD INSULATION; HEAT MOVES BY CONVECTION. Prevent heat loss at night Attract heat in day. ACTIVE SOLAR HEATING. ACTIVE SOLAR. SOLAR. - PowerPoint PPT PresentationTRANSCRIPT
CH. 12
RENEWABLE ENERGY
PASSIVE SOLAR HEATING
BUILDING PLACEMENT,MATERIAL, AND DESIGN ex: LARGE SOUTH-FACING WINDOWS (N. Hemisphere) WITH GOOD INSULATION; HEAT MOVES BY CONVECTION
Prevent heat loss at nightAttract heat in day
ACTIVE SOLAR
SOLAR
PROS CONS
No air pollutantsLittle maintenance
Not all areas get enough reliable sun
High start-up costs
INCENTIVES: tax break or rebate for installation
New technology should lower costs
Can be incorporated into building materials
Roofing shinglesTileWindow glass
Photovoltaic Solar Cells
windFastest
growing alt.
Costly to build, loud, bird flight patterns
No pollution, muliple use land
19% world
HYDROGEN FUEL CELLSSPLIT H2O
(photovoltaic cells or wind); requires energy; needs to be cheaper
No Sox, no CO2, some Nox (N + O + heat)
Hydrogen powered cars
Hydrogen as a Fuel Source-Electrolysis
HYDROELECTRIC
No pollutantsThermal pollutionDams rivers destruction of habitats, people uprootedSiltingSalmonWater loss due to evaporationFlood control (also, channels, identify flood prone areas, levees, wetlands intact)Breeding for disease vectors (mosquitoes & snails): malaria and
schistosomiasisMany rivers in US protected under Wild and Scenic Rivers Act
CASE STUDY: THREE GORGES DAM, CHINA
Small scale hydroelectricNo dams - no reduced salmon populations, no
reduced silt/nutrients down streamso no reservoir – no flooding of ecosystem
upstream, no excessive water evaporation, no water-borne disease vectors
Less river flow (less snow melt) in summer = less energy in summer
BIOMASSAny carbon-based, biologically derived fuel source
(wood, manure, charcoal, biogas – biodiesel, ethanol)½ of renewable in US; 3% of all US energyCommon plants – corn/sugarcane.Modern carbon vs fossil carbon+: could use wastes, reduce ff use, offset CO2 by
planting trees, no SOx-: requires land/water/ff to grow, competes with
growing food, take crops waste from soil, deforestation, ethanol = less energy content
Biogas (like methane) produced using a biogas digester (right pH, moisture) for bacteria
Or liquid (biodiesel, ethanol) for engines.Gasoline + ethanol = gasohol
BRAZIL
Ocean waves
Ocean Thermal Energy (OTEC)futureTemperature gradients between top and
bottom (from sun)Top water pumped (takes energy) into
power plant to boil liquid (ammonia) to create steam and drive a turbine.
Renewable, but not direct/indirect solar
TIDAL GEOTHERMAL
POPULAR IN ICELAND; US MAKES MOST
ENERGY CONSERVATION and EFFICIENCY
Reduce emissions, buy time, save energy for laterEnergy consumption greatest in HDC, but quickly
growing in LDC as standard of living increasesEfficient appliances (Energy Star)Efficient vehiclesFlorescent lightbulbs use 25% energy of
incandescent bulbs2001 refrigerator 75% less energy than 1970s (save
$135 per yr)
Efficiency calculationsPercent efficiency = Output/input (100%)
that is….o (Useful energy produced/total energy inputted)
Saving Energy at Home
THE ROLE OF RENEWABLE ENRGY CONSUMPTION IN THE NATION’S ENERGY SUPPLY, 2004 AND 2009.
2009
2004
ENERGY AND VEHICLES2/3 OF US PETROLEUM USAGE IS FOR
TRANPORTATION
3% US; primary transportation for othersBuses, trolleys, trains, subways – carry
more
MASS TRANSIT