PEE 6.2 Renewable Energy Resources

Question 1

Resources that replaced by natural processes and that can be used forever, provided they are not overexploited in the short term.

Answer 1

Renewable Resources

Question 2

Direct Solar Energy

Answer 2

1. Active Solar Heating
2. Passive Solar Heating
3. Photovoltaic (PV) Solar Cell
4. Solar Thermal Electric Generation (Concentrated Solar Power or CSP)

Question 3

A system of putting the sun’s energy to use in which collectors absorb solar energy and pumps or fans distribute the collected heat.

Answer 3

Active Solar Heating

Question 4

A system of putting the sun’s energy to use that does not require mechanical devices to distribute the collected heat.

Answer 4

Passive Solar Heating

Question 5

A wafer or thin film of solid-state materials, such as silicon or gallium arsenide, that is treated with certain metals in such a way that the film generates electricity when solar energy is absorbed.

Answer 5

Photovoltaic (PV) Solar Cell

Question 6

A means of producing electricity in which the sun’s energy is concentrated using mirrors or lenses onto a fluid-filled pipe; the heated fluid is used to generate electricity.

Answer 6

Solar Thermal Electric Generation (Concentrated Solar Power or CSP)

Question 7

Solar Thermal Electric Generation (Concentrated Solar Power or CSP) - Advantage

Answer 7

1. High potential for growth
2. No direct emissions of CO2 and other air pollutants.
3. Lower costs with natural has turbine backup
4. Source of new jobs

Question 8

Solar Thermal Electric Generation (Concentrated Solar Power or CSP) - Disadvantages

Answer 8

1. Low net energy yield and high costs.
2. Needs backup or storage system on cloudy days.
3. Requires high water use.
4. Can disrupt desert ecosystems.

Question 9

Energy that uses plant and animal material as fuel.

Answer 9

Biomass Energy

Question 10

Solid Biomass Energy Advantage

Answer 10

1. Widely available in some areas.
2. Moderate costs
3. Medium net energy yield.
4. No net CO2 increase if harvested, burned, and replanted sustainably.
5. Plantations can help restore degraded lands.

Question 11

Solid Biomass Energy (Disadvantages)

Answer 11

1. Contributes to deforestation.
2. Clear-cutting can cause soil erosion, water pollution, and loss of wildlife habitat.
3. Can open ecosystems to invasive species.
4. Increases CO2, emissions if harvested and burned unsustainably.

Question 12

Liquid Biofuels (Advantages)

Answer 12

1. Reduced CO2 emissions for some crops.
2. Medium net energy yield for biodiesel
3. Medium net energy yield for ethanol from sugarcane.

Question 13

Liquid Biofuels (Disadvantages)

Answer 13

1. Fuel crops can complete with food crops for land and raise food prices.
2. Fuel crops can be invasive species.
3. Low net energy yield for corn ethanol and for biodiesel from beans.
4. Higher CO2 emissions from corn ethanol

Question 14

Electric energy obtained from surface air currents caused by the solar warming of air.

Answer 14

Wind Energy

Question 15

Wind Energy (Advantages)

Answer 15

1. High net energy yield.
2. Widely available.
3. Low electricity cost.
4. Little or no direct emissions of CO2 and other air pollutants.
5. Easy to build and expand.

Question 16

Wind Energy (Disadvantages)

Answer 16

1. Needs backup or storage system when winds die down.
2. Visual pollution for some people.
3. Low-level noise bothers some people.
4. Can kill birds if not properly designed and located.

Question 17

A form of renewable energy that relies on flowing or falling water to generate electricity.

Answer 17

Hydropower

Question 18

Hydropower (Advantages)

Answer 18

1. High net energy
2. Large untapped potential
3. Low-cost electricity
4. Low emissions of CO2 and other air pollutants in temperate areas.

Question 19

Hydropower (Disadvantages)

Answer 19

1. Large land disturbance and displacement of people.
2. High CH4 emissions from rapid biomass decay in shallow tropical reservoirs
3. Disrupts downstream aquatic ecosystems.

Question 20

Energy from Earth’s interior, used for space heating or generation of electricity.

Answer 20

Geothermal Energy

Question 21

Geothermal Energy (Advantages)

Answer 21

1. Medium net energy yield and high efficiency at accessible sites.
2. Lower CO2 emissions than fossil fuels.
3. Low cost at favorable sites.

Question 22

Geothermal Energy (Disadvantages)

Answer 22

1. High cost except at concentrated and accessible sources.
2. Scarcity of suitable sites.
3. Noise and some CO2 emissions.

Question 23

A form of renewable energy that relies on the ebb and flow of the tides to generate electricity.

Answer 23

Tidal Energy