FINAL EXAM

Question 1

Since 1850, the energy consumption patterns in the US have changed dramatically. Briefly describe these changes (from both technical and societal perspectives).

Answer 1

Shifted from predominantly wood and biomass to fossil fuels (coal, oil, natural gas)

Transition driven by industrialization and technological advancements, leading to increased energy demand.

Shift brought about urbanization, transportation development, and higher living standards

Environmental concerns such as pollution and climate change.

Question 2

How has the percentage of renewable energy production changed over the past two decades?

Answer 2

Percentage of renewable energy production in the US has steadily increased

Growth driven by:
- A dvancements in renewable technologies
- Government incentives
- Heightened environmental awareness

Renewable energy still constitutes a relatively small portion of total energy production compared to fossil fuels

Question 3

What are Renewable Portfolio Standards and why are they important?

Answer 3

Renewable Portfolio Standards (RPS): regulations that require a certain percentage of electricity to be generated from renewable energy sources

• Important for driving investment in renewable energy infrastructure, reducing greenhouse gas emissions, diversifying the energy mix, and enhancing energy security.

Question 4

What is ‘peak load’ and what challenges does it pose for renewable technologies? How might renewables be used to reduce ‘peak load’?

Answer 4

Peak load: refers to the maximum electricity demand on the power grid at a given time

Renewable technologies: face challenges in meeting peak load due to intermittency and variability in energy production
- To reduce peak load, renewables can be integrated with energy storage systems, demand-side management strategies, and smart grid technologies to provide reliable and flexible power supply.

Question 5

How is coal formed? Be specific.

Answer 5

Coal: formed from the remains of plants that lived in swampy environments millions of years ago

• Over time, organic matter undergoes biochemical and physical processes (burial, compaction, heating transforming into peat, lignite, sub-bituminous coal, bituminous coal, and finally anthracite coal through coalification.

Question 6

What is non-conventional oil? Give three examples.

Answer 6

Non-conventional oil: oil resources that are more difficult and costly to extract compared to conventional crude oil.
- Oil sands (bitumen)
- Oil shale (kerogen)
- Heavy oil (high-viscosity crude oil)

Question 7

What is a potential use of methane hydrates?

Answer 7

Methane hydrates: crystalline compounds composed of methane molecules trapped within ice-like structures.
- Potential uses:
- Future energy source due to vast reserves

Question 8

What are “tar sands”? What is the major policy decision currently facing the U.S. related to tar sands?

Answer 8

Tar sands (oil sands): mixture of sand, clay, water, and bitumen (thick, viscous petroleum)

• Major policy decision: whether to permit the construction of pipelines (Keystone XL pipeline) transporting tar sands oil from Canada to US Gulf Coast for refining

Question 9

Why is coal production expected to peak later than oil? What impact is projected coal production likely to have on climate?

Answer 9

Coal production: expected to peak later than oil due to the abundance of coal reserves and the slower rate of depletion.

Projected coal production: likely to exacerbate climate change by releasing large amounts of carbon dioxide when burned for energy generation, contributing to global warming and environmental degradation.

Question 10

What is Carbon Capture and Sequestration? What are the benefits of this technology and some of the remaining challenges?

Answer 10

Carbon Capture and Sequestration (CCS):
- Captures carbon dioxide emissions from industrial processes and power plants
- Transports to storage sites
- Injects into underground geological formations for long-term storage

Benefits:
Reducing greenhouse gas emissions
Mitigating climate change
Enabling use of fossil fuels

Question 11

How do we harness energy from nuclear plants?

Answer 11

Energy from nuclear plants: harnessed through nuclear fission
- Nucleus of a heavy atom splits into smaller nuclei
- Releases large amount of heat energy
- Heat used to produce steam and power turbines connected to generators (electricity)

Question 12

What is the Waste Isolation Pilot Plant?

Answer 12

The Waste Isolation Pilot Plant (WIPP): deep geological repository located in New Mexico, USA; designed for the permanent disposal of transuranic radioactive waste left from the research and production of nuclear weapons.

Question 13

What is Yucca Mountain and when is it expected to begin receiving nuclear waste?

Answer 13

Yucca Mountain: proposed deep geological repository for the permanent disposal of high-level radioactive waste from nuclear power plants and military sources

Construction has faced numerous delays and controversies, and it is uncertain when it will begin receiving nuclear waste.

Question 14

Briefly describe some of the environmental conditions discovered at Yucca Mountain that raised concerns about safety?

Answer 14

Environmental conditions at Yucca Mountain:
- Presence of fault lines
- Potential for groundwater contamination
- Possibility of volcanic activity in the region

Question 15

Until a permanent high-level nuclear waste repository is established, what is the preferred method to handle nuclear waste from power plants?

Answer 15

Preferred method to handle nuclear waste from power plants is interim storage at on-site facilities or centralized interim storage facilities.

Question 16

What areas tend to have the greatest potential for generation of electricity from wind?

Answer 16

Coastal regions

Mountain passes

Open plains

Question 17

What were the advantages and disadvantages of the Cape Wind Project’s location?

Answer 17

Advantages:
- Proximity to densely populated areas
- Potential to harness strong offshore winds

Disadvantages:
- Opposition from local communities
- Concerns about visual impacts
- Regulatory challenges

Question 18

Describe one of the main obstacles to the development of the Cape Wind Project?

Answer 18

Opposition from local residents, environmental groups, and political leaders who raised concerns about its impact on marine life, navigation, and scenic views.

Question 19

What are some strategies being used to develop offshore wind, following the failure of the Cape Wind Project?

Answer 19

Strategies:
- streamlining permitting processes
- conducting comprehensive environmental assessments
- engaging with stakeholders early in the project development process

Question 20

Describe the two primary uses of geothermal energy?

Answer 20

Electricity generation: harnessing heat from underground reservoirs to drive turbines and produce electricity

Direct heating and cooling:
- Utilize geothermal heat pumps to transfer heat between ground and buildings

Question 21

Briefly describe how heat flows relative to differences in temperature.

Answer 21

Heat flows from areas of high temperature to areas of low temperature through:
- Conduction
- Convection
- Radiation

Question 22

What is the main technical challenge facing the production of electricity from geothermal in the Northeast US?

Answer 22

Relatively low temperature and permeability of subsurface rocks
- Limit the efficiency and feasibility of geothermal power generation

Question 23

What is the main technical challenge that Solar and Wind must overcome before being able to replace the use the natural gas and goal?

Answer 23

Intermittency: generate electricity only when the sun is shining or the wind is blowing

Question 24

Describe one way in which Hydropower may be able to help address the challenge described above. What are some limitations in this strategy?

Answer 24

Providing a reliable source of renewable energy that can be used to balance fluctuations in supply.

Limitations:
- Environmental impacts
- Habitat disruption
- Fish migration barriers

Question 25

With regard to Hydroelectric energy, what is the difference between High Head/High Power and Low Head/Low Power?

Answer 25

High head/High power: utilize steep elevation changes and large water flows to generate electricity efficiently

Low head/low power: rely on smaller elevation changes and slower water flows, requiring larger installations to generate comparable power.

Question 26

What conditions are most favorable for the generation of electricity from a geothermal resource?

Answer 26

Proximity to active tectonic plate boundaries or volcanic regions
- Heat from the Earth’s mantle is closer to the surface

Question 27

What are the pros and cons of installing a geothermal heating system in your home?

Answer 27

Pros:
- Lower operating costs
- Reduced carbon emissions
- Consistent heating and cooling year-round

Cons:
- Expensive installation
- Site-specific limitations
- Potential groundwater contamination risks

Question 28

What are some of the sources of revenue that can help to finance a renewable energy system?

Answer 28

Sources of revenue:
- Government incentives
- Tax credits
- Grants
- Feed-in tariffs
- Renewable energy certificates
- Power purchase agreements

Question 29

Briefly describe one way that tidal energy can be captured.

Answer 29

Tidal turbines: similar to underwater wind turbines, installed on the seabed in areas with strong tidal currents
- As tides flow in and out, they drive the turbines, generating electricity

Question 30

What are the main obstacles to increasing the use of hydroelectric power in New England?

Answer 30

Obstacles:
- Limited availability of suitable sites for hydroelectric dams
- Environmental concerns related to habitat disruption and fish passages
- Regulatory constraints

Question 31

What is Concentrated Solar Power and how does it avoid the main problem of Solar Photovoltaic Cells?

Answer 31

Concentrated Solar Power (CSP): Uses mirrors or lenses to concentrate sunlight onto a small area, heating a fluid to produce steam that drives a turbine and generates electricity
- Avoids intermittency by providing a more predictable and controllable source of solar energy

Question 32

What is the main driver behind the increased capacity in Wind and Solar PV over the past decade?

Answer 32

Declining costs due to technological advancements, economies of scale, and supportive government policies such as renewable energy mandates and subsidies

Question 33

What benefits might hydrogen provide for the transition to renewable energy?

Answer 33

Benefits of Hydrogen to Rewneable Energy:
- Clean and versatile energy carrier for storing and transporting renewable energy
- Powering fuel cell vehicles
- Supplementing intermittent renewable energy sources (solar, wind)