Climate Change and Energy Production

IB ESS Topic 7 - Climate Change and Energy Production https://docs.google.com/document/d/1vnoCd85jvOgrw-G7m9-fLPk9QQiRIXMurkLU13kD3bs/edit

Nonrenewable energy

Nonrenewable energy

Stored energy (solar) from resources that exist in fixed amounts in the earth's crust. These can be depleted and are not replenishable by natural processes within a human time scale

Renewable energy

Energy from resources that can be replenished rapidly (hours to decades) through natural processes as long as it is not used up faster than it is replaced.

Net energy

Total amount of useful energy available from a resource, minus the energy needed to make the energy available in the first place.

Energy return on investment

 Energy obtained per unit energy used to obtain it

First law of thermodynamics

It takes high quality energy to get high quality energy. Energy is expended in the process of pumping oil from the ground, refining it, transporting it.

Second law of thermodynamics

Some high quality energy is wasted at every step along the way. Entropy. Things get more chaotic as time goes on. 

Current status of ITER project

The ITER Project’s JET (Joint European Torus), the first device to create controlled fusion power, has delivered its final plasma after 40 years of operation. Now, in early 2024, it will be moving on to the next stage -- repurposing and decommissioning, which will last until 2040. In the meantime, ITER has continued to update the main ITER project, one recent development being in Korea. The Korea Institute of Fusion Technology recently equipped its KSTAR with new diverter technology. This new diverter can take in twice as much of a thermal load than its predecessor. The ITER start for creating plasma is scheduled for late 2025.

Update on nuclear fusion

The biggest breakthrough in recent years occurred in December 2022, when scientists at the US National Ignition Facility were able to achieve ignition: a fusion reaction that produced more energy than it consumed. This experiment was repeated again at the Lawrence Livermore National Laboratory, who also was able to achieve ignition and produced an even higher yield than the one in December 2022. Just recently in December 2023, the world’s largest experimental nuclear fusion reactor has been inaugurated in Japan. This project is a collaboration between Japan and the European Union and is a forerunner for ITER.

Nuclear Energy: Summary of Process

ULTIMATE SOURCE: atomic nuclei in decay

• How does a Nuclear Fission Reactor Work?

  • Controlled/timed nuclear fission reaction within a sealed reactor (unlike nuclear weapons)

    • Many types of reactors - light water reactors most common (relatively cheaper)

      • LWRs are power by uranium ore, which is packed as pellets into fuel rods

        • Within uranium atoms, nuclear binding energy is released in the form of electromagnetic radiation

        • This radiation is used to turn liquid water into steam, which then spins a turbine

        • Vast amounts of freshwater used to moderate temps within these systems - huge cooling towers - reactors mainly built on or near water

    • But, these are also problematic - old tech (60s, 70s), less than 40% inefficient

Advantages of Nuclear Energy

• Low impact, low carbon energy (no combustion)

Thermal pollution

• “Nuclear power plants discharge 50% more waste Rheat to the atmosphere through cooling towers or to a water body than coal-fired plants.” (NLM)

  • Temperature variations affect metabolic rates of organisms and dissolved oxygen levels. Can often increase the susceptibility of organisms to toxic substances. (IntechOpen)

• The use of cooling towers, man made ponds, etc, help to minimize these impacts. Water may also be treated before being released. Of course, however, this does add to expenses

• This ScienceDirect article suggests that thermal pollution is usually “small or even insignificant”. 

Radioactive waste

• Nuclear fuel is energy dense, so the amount of waste produced is relatively small

  • “On average, the waste from a reactor supplying a person’s electricity needs for a year would be about the size of a brick. Only 5 grams of this is high-level waste – about the same weight as a sheet of paper.” (World Nuclear Association)

• Storage and disposal

  • Often kept in wet storage to be cooled, diminishing heat and radioactivity; then typically either disposed of through recycling or direct disposal. Direct disposal - placed in a repository underground in sealed canisters.

    • Will remain weakly radioactive for a few hundred thousand years, but will likely cause no harm to human health whatsoever

Building and maintenance costs

• Capital costs: 60% site preparation, engineering, manufacturing, construction, commissioning, and financing

• Operating costs: fuel costs (from uranium mining to fuel fabrication), maintenance, decommissioning, and waste disposal

  • Capital cost far higher for nuclear than for nonrenewables like coal - nuclear plants are more technically complex, stricter safety standards

  • Newer, more advanced reactor designs have improved operational efficiency and thes cheaper operating costs

Nuclear weapon proliferation

• NRDC

  • When countries have access to the technology/resources for nuclear power, they have the capacity to also manufacture warheads

    • “In a number of countries, peaceful nuclear materials and equipment have been diverted to secret nuclear weapons programs.”

  • UN Treaty on Non-Proliferation of Nuclear Weapons (1970)

    • Near-universal participation

    • “...countries with nuclear arsenals…must negotiate and reduce their nuclear weapons stockpiles, ultimately eliminating these weapons of mass destruction”

      • However, nuclear weapons are currently increasing in quantity

Historically, low net energy yield

• Typical reactor produces 1 GW of energy - high capacity for energy generation (Energy.gov)

  • Large amounts of energy are needed for each step in the reactor cycle, significantly lowering net energy yield

Three Mile Island (1979)

• Outside Harrisburg, PA: nuclear power plant

  • Accident: cooling system broke down, some radioactive steam escaped into the air

    • Inside the too-hot reactor, a potentially explosive air bubble developed

  • High radiation ratings in the plant area - pregnant woman and children had to evacuate after 3 days.

    • Five years later, the reactor was opened up and half the fuel was found to have melted

    • Overall, there were no casualties, but the meltdown could have been worse than anticipated

    • Cleanup took nearly a decade, extremely expensive

Chernobyl (1986)

• April 26th, 1968: Chernobyl, Ukraine

  • Some operator actions - including disabling of automatic shutdown mechanisms - reactor was unstable

  • Massive power surge when control rods were inserted into reactor

    • Caused a steam explosion, then a second explosion. The graphite and fuel fragments from the explosion started a number of fires

• Immediate impact: massive release of radiation into surrounding environment. The firefighters who responded to the scene experienced acute radiation syndrome (ARS)

• The town of Pripyat was evacuated on April 27. By May 14th, 116,000 people that had been living within 30km radius had been evacuated and later relocated. Belarus, Russia, and Ukraine experienced the most significant effects of the radiation, but the fallout did spread throughout Europe as a whole

Fukushima Daiichi (2011):

• Earthquake - March 11, 2011

  • Generated tsunami waves that damaged the backup generators at the Daiichi plant (constructed in the 1970s)

  • Loss of power caused cooling systems to fail. Because of the lack of cooling, heat caused the fuel rods in the first 3 reactors to overheat and partially melt down

    • Explosions from buildup of pressurized hydrogen gas

    • Another explosion March 15

• Surrounding area evacuated

• Workers attempted to cool the plant with water, which temporarily slowed the release of radiation

• Radiation began appearing in local food and water supplies

• Placed on the same severity level as Chernobyl

Recent domestic nuclear progress

Domestic: US approves a non-water-cooled nuclear reactor

• Construction permit for a new nuclear test reactor to be built in Oak Ridge, Tennessee

  • First non-water-cooled reactor to be approved for construction in U.S. in over 50 years

  • Instead of water, this reactor would utilize molten salt as a cooling agent

  • Project received $303 million of Department of Energy funding

  • The project will require a separate operating license after its built from the US Nuclear Regulatory Commission

Abroad: EU to launch industrial alliance on small nuclear reactors

• To promote the development of small modular reactors, the European Commission has launched an industrial alliance

• These SMRs will be less expensive and time consuming to build

• Several projects are being planned throughout Europe - for example a cluster of six is being planned for the site of a decomissioned coal plant in Romania

What’s warming the Earth? (3 natural factors and 4 anthropogenic factors)

Natural:

1. The Earth’s orbit

2. The Sun’s temperatures

3. Volcanic activity

Anthropogenic:

1. Deforestation

2. Ozone pollution

3. Aerosol pollution

4. Greenhouse gases

What is the IPCC and what does the acronym stand for?

The Intergovernmental Panel on Climate Change - the United Nations body for assessing science relating to climate change.

What is the purpose of their reports, published every 7-8 years?

To provide updates on the state of scientific/technological/socioeconomic knowledge on climate change, potential impacts, and what can be done to reduce the rate of climate change.

Why was the IPCC created?

“The IPCC was created to provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options.”

IPCC A.4

Current Mitigation Progress, Gaps and Challenges

Policies and laws addressing mitigation have consistently expanded since AR5.

Global GHG emissions in 2030 implied by nationally determined contributions (NDCs) announced by October 2021 make it likely that warming will exceed 1.5°C during the 21st century and make it harder to limit warming below 2°C.

There are gaps between projected emissions from implemented policies and those from NDCs and finance flows fall short of the levels needed to meet climate goals across all sectors and regions.

Conventional Oil

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

Ultimate source: sun Conventional crude oil is petroleum Heat/refine into various fuels at different boiling points Then can be used in combustion engines or to create steam and spin turbines Main concern is peak production: time after which production from the well sees a sharp decline Proven resources may not last to 2100 Unconventional heavy oil: higher environmental and production cost

Crude oil is not a single product, as it boils it creates a variety of products. Ample supply for several decades Net energy yield is medium (but decreasing) Low land disruption Efficient distribution system

Crude oil cannot be used straight out of the ground. Water pollution from oil spills and leaks Environmental costs not included in market price Releases CO2 and other pollutants when burned Vulnerable to international supply interruptions

Oil Shale and Tar Sand

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

Ultimate source: sun To use it we must: Extract kerogen from shale rock, or bitumen from tar sands, distill it into heavy oil, and then heat and use same way as conventional oil 72% of world’s reserve is in arid areas of western US Locked up in rock - requires huge amounts of water for extraction / processing Because of this, very low net energy yield Extensive tar sand deposits in Canada and Venezuela Extraction is an environmental nightmare: extensive mining and processing

Large potential supplies Easily transported Efficient distribution system in place

Low net energy yield Releases CO2 and other pollutants when produced and burned Severe land disruption, high water use

Natural Gas

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

Ultimate source: sun Find gas deposits in crustal rocks (seismic surveys) Conventional extraction: vertical reinforced pipes, fracking of shale rock Fracking = increased environmental concern Can also be found in methane hydrates compounds (permafrost and on the seafloor) but too expensive Lastly: burned to heat water/air

Ample supply Versatility Mediym net energy field Good transition option: emits far less CO2 and other pollutants when burned

Low net energy yield for liquid natural gas Production/delivery may emit more CO2 and CH4 per unit of energy produced than coal Fracking uses and pollutes large volumes of water Potential groundwater pollution from fracking Possible link to increased seismic activity

Coal

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

Ultimate source: sun

Mine it from the crust Burn it (creates steam to power engines or spin turbines) Can also be converted to: Synthetic Natural Gas (SNG) by coal gasification Methanol or synthetic gasoline by coal liquefaction (Synfuels)

Ample supply in many countries Medium to high net energy yield Low cost (not including environmental cost)

Severe land disturbance, water pollution Fine particle, toxic, mercury emissions are a threat to human health Emits large amounts of CO2 and other air pollutants when produced and burned

Hydroelectric

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating electricity on a large scale

Movement of water through rivers, lakes, and dams spins blades of a turbine, which powers a generator.  Turbines are powered by pump-storage reservoirs

Low quality energy input, high quality energy output (90% energy efficiency) Creates water reserves, energy supplies Safe Flexible - can quickly go from zero power to maximum output, good for backup power in outages

Expensive to build Flood risks Dams strongly impact local hydrology (water movement and distribution) Can be problematic for deltas Silting of dams Lack of water downstream

Large scale plants can produce electricity at a large scale Generates 16% of the world’s energy (3rd largest source) Expense of implementing makes it difficult, but overall very feasible

Solar/Photovoltaic Cell

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating electricity on a large scale

Solar radiation is converted into electricity via chemical energy

Energy supply is potentially infinite Allows for single dwellings to be self sufficient on energy Safe Converts low quality energy to high quality energy

Expensive manufacture and implementation Cannot work in the dark High maintenence

Generally, not incredibly efficient, but has potential to be implemented on larger scale. Intermediate efficiency PV covering 0.6% of US land would produce enough energy to fulfill national demand

Concentrated Solar Power (CSP)

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating energy on a large scale

To use: Mirrors reflect and concentrate sunlight Energy from concentrated sunlight heats - thermal energy - this is used to spin turbine or generator Parabolic trough mirrors - type of curved mirror to more effectively direct it

Solar energy is renewable Cost of power stations = fossil fuel power stations

Requires a highly insulated area (tropics) Requires large amounts of land and sunlight Relatively new technology

Feasible for larger scale; capable of powering homes across the US easily and progressing to becoming more and more cost-effective Sun is constant

Biomass

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating energy on a large scale

Sun

Plants photosynthesize and produce chemicals, respiration Burning organic matter releases heat - conversion of energy

Can generate electricity, heat homes, power industry Easy to locate sources (eg. farm byproducts) Can be used to create a more sustainable form of oil

Air pollution - methane is released in process Land can be negatively affected (deforestation) Complications with food production - land is needed to create biomass in first place

Biomass establishments already exist, US Dep of Energy estimates that it may provide up to 20% of the country’s energy by 2030

Wind

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating energy on a large scale

Sun - Wind is powered by the sun’s uneven heating of the Earth’s surface

Wind spins the blades of a turbine around a rotor, which spins a generator and creates power

Clean energy supply Low maintenence Becoming increasingly efficient and cost effective

Wind is needed Windy sites aren’t close to highly populated areas Manufature/implementation is expensive Some noise pollution “Visual” pollution Possibility of hurting birds or migration routes

While relatively efficient, it can’t be easily implemented everywhere. Offshore allows for more wind power potential in smaller, coastal countries, but smaller landlocked countries may not be able to implement.

Tidal/Wave

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating energy on a large scale

Sun/Moon - gravitational force of the earth combined with sun and the moon control the tides

Tidal: movement of seawater in and out drives turbines Tidal barrage is built across estuaries Waves: movement of seawater in and out of cavity on the shore, compresses air that pushes a turbine

Ideal for island countries High potential for energy production Tidal barrage can also act as a bridge Better for smaller scale - local power

Costly consutruction of barrage Not every estuary is suitable May have detrimental impact on wildlife May disrupt tidal flow and flow of sewage May disrupt shipping

There is potential for larger scale, but definitely more viable at a smaller scale to supplement existing energy supplies. Best for small nations with shorelines, esp islands - cannot be universally implemented

Geothermal

• Ultimate Source

• Summary of Process

• Advantages

• Disadvantages

• Feasibility for generating energy on a large scale

Heat under the earth

Typically in places with volcanic activity Cold water is pumped into volcanic regions, releasing steam Steam spins a turbine

Potentially infinite supply Clean energy

Expensive to set up Can only be established in places with volcanic activity Some dangerous gases can be released

Not very feasible - not very dependable, requires specific circumstances to work