Renewable Energy Test Flashcards Preview

AP Environmental Science > Renewable Energy Test > Flashcards

Flashcards in Renewable Energy Test Deck (28)
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1
Q

Ethanol (Sugarcane) Pros:

A

Cost effective, homegrown, renewable, less greenhouse gas emissions, higher net energy than corn, less expensive than gasoline, production can be close to ethanol refineries.

2
Q

Tidal Energy Methods

A

Anaconda - water runs through a tube in the water and waves that run through it turn a turbine
Tidal Dams - hole in dam with turbine in the middle, water runs through it and spins turbine

3
Q

Tidal Energy Pros

A

We can predict tides, 80% efficiency, Low maintenance, 71% of earth is water

4
Q

Wind Energy Pros and Cons

A

Perpetual, 1 turbine = electricity for 500 homes, cheap and decreasing, moderate to high net energy yield, widely available, low electricity cost, no emissions, easy to build and expand

5
Q

Photovoltaic Panel

A

Cells that are connected electrically make up one panel; 29 states have adopted PV cells, target is SW states with most sunlight

6
Q

Solar Energy for High Temperature Heat and Electricity Methods

A

Parabolic Through Systems - U-shaped mirrors that reflect sun to heat oil
Power Tower - computer powered mirrors that follow sun and reflect onto main tower.
Dish Engines - big mirrors track sun to reflect and heat gas

7
Q

Solar Energy for High Temperature Heat and Electricity Pros and Cons

A

Pros: Clean power, jobs, could meet 25% of worlds electricity
Cons: moderate land/environmental impact

8
Q

Hydrogen Fuel Cells Pros and Cons

A

Pros: quicker refueling than battery, double the efficiency of normal cars, can be produced from plentiful water at some sites, no emissions, good substitute for oil
Cons: 1 ton of hydrogen = 11 tons of CO2, 96% of hydrogen in made from fossil fuels, negative net energy yield, high costs require subsidies, needs H2 storage and distribution systems;

9
Q

Geothermal Energy for Electricity

A

Dry geothermal: pump cold water into core and heat it into steam
Aquifer Extraction - taks hot water from aquifers and springs

10
Q

Geothermal Energy for Heating Pros and Cons

A

Pros: always available, 1/6 CO2 than other fossil fuels, moderate net energy and high efficiency at accessible sites, lost costs at favorable sites
Cons: Possible toxic solutions used to get heated, high costs and low efficiency except at concentrated and accessible sites, scarcity of suitable sites.

11
Q

Energy Conservation Methods (10)

A

Unused Plugs draw 10% of energy so use a power strip to be able to turn all of that off
Low emission windows, trees, dual-flush toilets, good insulation, geothermal heating, passive solar heating, energy efficient appliances and lighting.

12
Q

Hydroelectricity Methods, Location and Advantages/Disadvantages

A

Large scale dams - no pond needed = no flooding or relocation
Falling Water - uses natural heights to power electricity
Concentrated in 3 states - Cali, Oregon and Washington
Pros: 90% efficient, no waste and very reliable, large untapped potential, low-cost electricity
Cons: Large land disturbance and displacement of people, high methane emissions from rapid biomass decay, disrupts downstream ecosystems

13
Q

Waste to Energy Incinerator Pros and Cons

A

Pros: reduces trash, reliable source, creates jobs, reduces CO2 emissions from trash that would have been in landfill
Cons: costs $200 million to build, concentrated wastes, harmful waste

14
Q

Cogeneration

A

When two forms of energy are produced from the same fuel source. They can then both be used instead of one being wasted.

15
Q

What % of electricity is wasted by incandescent lightbulbs? What are the alternatives?

A

95%, LEDs or CFLs which last about 100 times longer than incandescent

16
Q

Photovoltaic Panel Pros and Cons

A

Pros: moderate net energy yield, no direct emissions of CO2, east to install and move around, competitive costs for newer cells
Cons: need access to sun, need electricity storage system for backup, prices high for older ones but decreasing rapidly, could disrupt ecosystems

17
Q

What is the world’s leading renewable energy source for electricity?

A

Hydropower

18
Q

Solid Biomass Pros and Cons

A

Pros: widely available in some areas, moderate costs, no net CO2 increase if harvested, burned and replanted sustainably, plantations can help restore degraded lands
Cons: moderate to high environmental impact, increases CO2 if harvested unsustainably, clear cutting can causes soil erosion, water pollution and loss of habitat, often burned in inefficient and polluting open fires.

19
Q

What percent of energy for cooking does biomass provide for the world and then for poor countries?

A

World: 10%
Poor: 95%

20
Q

What is biodiesel?

A

It is fuel produced from vegetable oils in plants like soybean, rapeseed and sunflowers.

21
Q

Pros and cons of biodiesel

A

Pros: reduced CO2 emissions, high net energy yield for oil palm crops, reduced hydrocarbon emissions, better mileage (up to 40%)
Cons: Increased NOx emissions and smog, low net energy yield for soybeans, compete with food for cropland, clearing natural areas for plantations reduces biodiversity

22
Q

What is ethanol?

A

Fuel made from plants like switchgrass, sugarcane and corn. Converts the plant starches into simple sugars which are processed into ethanol

23
Q

Why is switchgrass an efficient way to make ethanol?

A

It makes cellulosic ethanol, which is produced from inedible cellulose that makes up most of the biomass of plants. It uses the starch in the stalks and husks of plants to make ethanol. This eliminates any food wastes and a much higher net energy.

24
Q

Pros and Cons Ethanol

A

Pros: some reduction in CO2 emissions, high net energy yield, potentially renewable
Cons: low net energy yield with corn and higher cost, higher CO2 emissions with corn, corn ethanol competes with food crops and may raise food prices.

25
Q

What % of energy is wasted in the US?

A

84%

26
Q

What percent of energy use does industry account for?

A

30-33%

27
Q

What percent of energy does a coal-fired power plant waste?

A

66-80%

28
Q

What percent of energy in the US is from renewable energy sources?

A

7%