AP Environmental Science Unit 6: Energy Resources and Consumption

Describe why coal is considered a nonrenewable energy source. 1 point
Accept one of the following:

- Nonrenewable energy sources like coal exist in a fixed/finite/limited amount.

- The formation rate of coal is less than the consumption/combustion rate of coal.

1 point electricity. Accept one of the following:

- Transport of natural gas (in pipelines) costs less than transport of coal (by rail).

- Natural gas (methane) harvested from a decomposition reaction (landfills, wastewater treatment plants, biodigesters) costs less than coal.

- There are fewer health-related issues linked to the burning of natural gas than are linked to burning coal, leading to lower health care costs for individuals or society as a whole.

- There are fewer pollution controls needed for a natural gas powerplant, decreasing the cost of operation/construction/permitting.

- There are lower combustion-residue disposal costs from the operation of natural gas burning powerplants than from coal-burning power plants.

- Natural-gas-burning power plants are much more efficient (more electricity output from the same energy input) than coal-burning power plants leading to lower fuel costs.

(2 points; 1 point for indicating how steam is produced to turn a turbine and 1 point for stating that the energy from the turbine is used to run a generator that produces electrical current)
Steam production (thermal energy into mechanical energy). Any of the following are correct responses:

- High-pressure hot water is pumped out of the earth and put into a low-pressure container to produce steam, which will in turn run a turbine (flash steam plant).

- Wells are drilled, and steam is piped directly to turn a turbine (dry steam plant).

- Hot water is pumped out of the earth; a heat exchanger is used to heat another liquid to produce vapor that is then used to turn a turbine (binary cycle).

Electrical production (mechanical energy into electrical energy)

- The energy from the turbine is used to run a generator.

China has become the world's largest emitter of CO_2. Explain this apparent contradiction. (1 point)
Although the per capita electrical energy consumption is low, China is the most populous country on the planet. The sum of individual consumption is large.