RENEWABLE RESOURCES Renewable Resources 1 Energy that CAN

RENEWABLE RESOURCES

Renewable Resources 1. Energy that CAN BE replaced as fast as it is used 2. Major types a) b) c) d) Solar Wind Hydropower Biomass i. What is the energy source for all of these?

Gathering Solar Energy 1. Active: Solar cells convert sunlight into electricity 2. Passive: Sunlight is used to naturally heat masonry in houses or provide natural lighting 3. Power plant: sunlight is focused onto a single point and used to heat water

Solar Power Compromises 1. BAD a) No sun at night b) Storing the energy is difficult; battery technology is not good enough c) Very expensive up front cost 2. GOOD a) Endless supply of energy b) No pollution c) Portable energy

Water Power 1. Kinetic energy of moving water

Dams and Reservoirs 1. Dams are built to hold water back 2. Water is released through the dam where it generates power

Water Power 1. Also known as hydropower 2. Largest source of renewable energy 3. Provides around 20% of global energy needs

Hydropower Compromises 1. BAD a) Disrupts natural habitats for fish and wildlife that depend on flowing water 2. GOOD a) Reliable power all day every day for many years b) No pollution

Wind Power 1. Winds are driven by the solar energy that heats the earth’s surface and its atmosphere 2. The differences in temperature between the poles and the equator create global winds

Wind Energy Compromises 1. BAD a) Wind is unpredictable b) Energy must be stored for windless days c) Expensive to build wind turbines 2. GOOD a) No pollution b) Can work on large or small scale c) Wind power will be a bigger part of the energy equation in the future

Biomass 1. Chemical energy from living or recently living material a) Wood, animal droppings, plants (corn)

Biomass Compromises 1. BAD a) Biofuels can divert food away from feeding people. This makes food more expensive b) Burning fuels releases some pollution 2. GOOD a) Biofuels hold a lot of energy per pound so they can be used, like oil, for transportation purposes b) Renewable

Geothermal Energy 1. This energy is NOT a fossil fuel and is NOT dependent on the sun’s energy 2. The heat from inside the earth is used to create steam to generate power

Geothermal 1. BAD a) Not available everywhere b) Drilling deep in the Earth can disrupt nature 2. GOOD a) No pollution b) Cheap c) Renewable

Net Energy 1. Net Energy: the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available 2. Every 5 barrels of oil consumed requires 1 barrel of oil to extract, refine, and transport a) Total net energy of oil: 5 barrels – 1 barrel = 4 barrels

Net-energy Ratio 1. The higher the net energy ratio, the more efficient the energy resource Energy Resource Net-energy Ratio Solar Energy 5. 8 Natural Gas 4. 9 Oil 4. 5 Coal-fired Electricity 2. 5 -5. 1

Energy Conservation 1. 2 main ways of conserving energy a) Use less energy b) Use energy more efficiently