Energy Alternatives Ch 16

16-3 Solar Energy

PASSIVE SOLAR What is it: Best used for: Best Locations: absorb & store heat from the sun directly in a well insulated structure (no machines) Best used for: Space heating Best Locations: Someplace Sunny 

Figure 16.10 Solutions: passive and active solar heating for a home. Fig. 16-10a, p. 411

ACTIVE SOLAR What is it: Best used for: Best Locations: Absorbing energy from the sun and pumping a heat-absorbing fluid through the house Best used for: Space or water heating Best Locations: 1 in 10 houses in China, also in Germany, Japan, Greece, Austria, Turkey, Spain & Israel

Figure 16.10 Solutions: passive and active solar heating for a home. Fig. 16-10b, p. 411

Rooftop Solar Hot Water on Apartment Buildings in China

P & A P & A P & A P & A P & A P & A A

Sustainable Energy: Rocky Mountain Institute in Colorado, U.S.

SOLAR THERMAL What is it: Best used for: Best Locations: Concentrating heat from the sun into high-temperature thermal energy Best used for: Generate electricity Can use directly for high temperature heating (like cooking) Best Locations: Mostly desert areas Spain, California

Commercial Solar Power Tower Plant Near Seville in Southern Spain

Solutions: Woman in India Uses a Solar Cooker

SOLAR CELLS (PHOTOVOLTAIC) What is it? Photovoltaic (PV) cells (solar cells) convert solar energy to electric energy Best used for? Producing electricity Best Locations Current large power plants Tucson, AZ (U.S.), Portugal, S. Korea, Germany Google is installing on its roof (power for building plus 1,000 homes) Could be distributed in rural or third world locations

Solutions: Using Solar-Cell Roof Shingles

Total Costs of Electricity from Different Sources in 2004

Solutions: Solar Cells for a Remote Village in Niger

Solar-Cell Power Plant in Arizona

16-4 Water Power

HYDROELECTRIC What is it? Best use: Best locations: Using the kinetic energy of moving water to produce electricity Best use: Electricity Best locations: Anywhere with falling water or the ability to build a large dam We have used up most of the world’s sites

TIDAL POWER What is it? Best use: Locations limited: Produce electricity from flowing water in the ocean tides and waves Best use: Electricity Locations limited: Current: France, Nova Scotia Working on installing in New York City

TIDAL POWER Disadvantages Few suitable sites High costs Equipment damaged by storms and corrosion 24

16-5 Producing Electricity from Wind

WIND What is it? Best use: Locations: an indirect form of solar energy, the kinetic/mechanical energy is captured by turbines and converted into electrical energy Best use: Produce electricity Locations: Dominated by Europe right now The Great Plains are our “Saudi Arabia of wind power” North Dakota, South Dakota, Kansas, Texas

Solutions: Wind Turbine and Wind Farms on Land and Offshore

Electricity from Wind Energy Is a Rapidly Growing Global Industry Countries with the highest total installed wind power capacity Germany United States Spain India Denmark Installation is increasing in several other countries

Wind Energy Is Booming but Still Faces Challenges Drawbacks Windy areas may be sparsely populated Winds die down; need back-up energy Storage of wind energy Kills migratory birds “Not in my backyard”

16-6 Advantages and Disadvantages of Biomass as an Energy Source

Solid Biomass Biomass isn’t on your chart, it is useful but it is unlikely that it will be a large scale contributor for industrialized nations.

BIOFUELS Best use: Biggest producers of biofuels What is it? Biofuels are liquid fuels produced from plants and plant wastes (biodiesel & ethanol) Best use: Replace gasoline in transportation Biggest producers of biofuels Brazil The United States The European Union China

BIOFUELS Disadvantages: Studies warn of problems: Decrease biodiversity Increase soil degrading, erosion, and nutrient leaching Push farmers off their land Raise food prices

Natural Capital: Rapidly Growing Switchgrass in Kansas, U.S.

ABC Video: MTBE pollution

16-7 GEOTHERMAL

GEOTHERMAL Best used for Locations What is it? Electricity generation Geothermal energy taps the heat stored in the earth’s soil, underground rocks and fluids in the earth’s mantle Best used for Electricity generation Space heating Locations Iceland, and any place that has “hot” crust Particularly out west for US

Getting Energy from the Earth’s Internal Heat (2) Geothermal energy: two problems High cost of tapping large-scale hydrothermal reservoirs Dry- or wet-steam geothermal reservoirs could be depleted

Natural Capital: A Geothermal Heat Pump System

16-8 Hydrogen as an Energy Source

HYDROGEN FUEL CELL What is it: Best used for: Combines hydrogen and oxygen to produce electricity (by product is water vapor) Best used for: Replacement for oil In homes to replace electricity

A Fuel Cell Separates the Hydrogen Atoms’ Electrons from Protons

Solutions for a More Sustainable Energy Future?

Solutions: Decentralized Power System

What Can you Do? Shifting to Sustainable Energy Use