Energy Systems + Sustainable Solutions Test 1 lectures 1-7

Energy Use/Demand is dictated by 3 things

Population

Energy Efficiency

Behavior/Choice

What percent of 2023 US Energy consumption was renewable

9%

What percent of 2023 US Energy consumption was natural gas?

36%

What percent of 2023 US Energy consumption was petroleum?

38%

What percent of 2023 US Energy consumption was Nuclear electric power?

9%

What percent of 2023 US Energy consumption was coal?

9%

What percent of 2023 world’s power was natural gas?

23%

What percent of 2023 world’s power was oil?

32%

What percent of 2023 world’s power was coal?

26%

What percent of 2023 world’s power was nuclear?

4%

What percent of 2023 world’s power was hydro?

6%

What percent of 2023 world’s power was other renewables?

8%

What do we use energy for?

Electricity Generation (biggest)

Heating and Cooling

Transportation

Why is the World Energy Chart so concerning?

• Both Developing and developed countries energy needs are rising at substantial rates

• We currently do not have enough energy infrastructure to provide for this rising energy need.

• Greater need means greater push to tap into non-renewables to meet energy needs.

• This can also be seen as an opportunity to invest in renewable energy sources.

• Over arching energy changes: Increase efficiency so we don’t waste as much energy.

• Change people’s behaviors

• Curb population growth?

Main points of IPCC 2023 Report

• Humans are the cause of climate change

• Increased weather events will also be more extreme

• Developing countries will be hit the hardest

• Need cooperation between countries within countries

• Mitigation efforts and solutions will become less effective as time goes on

• Environmental justice is a big issue

• Need to do something now

• There will be more conflict over resources

• We have the tech to deal with this, we just have to use it

Goal of the Inflation Reduction Act

Reduce inflation, investments in renewables, reshaping transportation, cut energy costs, create new jobs, help meet Paris goals,

Funding of Inflation Reduction Act

Taxes, $370 Billion over 10 years

Provisions of Inflation Reduction Act

Technology neutral for zero carbon sources, tax incentives for TVs, EJ components, infrastructure investments, local community projects.

Progress of Inflation Reduction Act

• 2025 reconciliation law cut significant funding

• Clean energy installations projected to be 20% lower than if no cuts to funding

• Clean energy generates 90% of new energy generation in the US

• Clean energy costs keep coming down (cheapest new source)

• Framework in place

• States picking up some of the slack

• EV adoption expanding, wind hitting hurdles (Feb 2024)

Energy

Amount of work that can be (or was) performed or the capacity to do work. Ex. Water in watering can

Power

Rate at which work is done.

Unit of Energy

kWh (kilowatt-hours) or Joule often megajoule - MJ)
•kW (10³), MW (10⁶), GW (10⁹), TW (10¹²)

Unit of Power

W (Watts)

Formula for = Energy(kWh)

(Power * Time)

Other units of Energy

BTUs, newton-meters, therms, calories

Potential Energy

Stored Energy that is potentially available for use

Kinetic Energy

“Energy in Motion” - Energy possessed by matter because of its gas and speed.

Michael Faraday

English chemist and physicist who contributed vastly to the study of electrochemistry and electromagnetism. His main discoveries include the principles underlying electromagnetic induction, diamagnetism, and electrolysis.

Law of Induction

Describes how an electric current produces a magnetic field and, conversely, how a changing magnetic field generates an electric current in a conductor.

What door did the law of induction open?

To convert mechanical force into electric current.

Electrons have what charge

Negative so you need a wire with

positive (+) (-) Negative = potential difference

First electric dynamo

1831, Capable of generating continuous flow of direct current.

Parts of Electrical Generator

Rotor: Rotates

Stator: Remains stationary

• Amature windings are copper coils that pass through the electromagnetic field (bundle of wire)

• Field windings create the electromagnetic field

• Brushes contact to collect current

Basis of most electricity generation

Need something to turn the shaft and the rotor

Volt: unit is (V)

The difference in electrical potential maintained between two terminals.

Amp (A)

The flow of electrons.

One amp is the current generated when 6.242 x 10¹⁸ electrons pass a particular point per second.

Formula for Power

= V x I, where I is current and V is voltage

Multimeter

Combined voltmeter and ammeter

Resistance (R)

• When a current runs through a material it will encounter some resistance.

• Resistance is the flip side of conductance

Ohm’s law

V=I x R, where I again is current

Steps for energy to get to your house

1) Power plant generates electricity

2) Substation transformer steps up voltage for transmission

3) Transmission lines carry electricity long distance

4) Neighborhood substation transformer steps down voltage

5) Distribution lines carry electricity to houses

6) Transformers on poles step down electricity before it enters houses.

Characteristics of the Grid

• Old + Out of shape

• Lots of other components (law, etc.)

• Runs lots of networks - national security concern

• No storage and no choice of electron generation

• Lots of inefficiencies

• Lots of outages (Squirrels and trees)

• Built to depend on constant, and centralized energy generation

• We need to reimagine the grid

How does temperature affect resistance

Higher temp means higher resistance.

As current flows, temp increases and therefore resistance

How does wire length affect resistance

The longer the length the greater the resistance.

Line losses increase with current, crackling under transmission wire

How does wire thickness affect resistance

The thicker the wire, the less resistance. Large currents require super thick wires.

Do we send high voltage or high current through the grid? Why?

High voltage because you can easily step it up and down. It also has a lot less problems than current because current is tricky and finicky and requires specific conditions.

Inverter

Converts DC to AC

Rectifier

Coverts AC to DC

every time you convert you lose power

Transformer

Steps up or steps down volts

Net Metering

A system in which solar panels or other renewable energy generators are connected to a public utility power grid and surplus power is transferred onto the grid - “behind the meter”

Remote Net Metering

Allows the electricity generated at one site to be distributed among many utility accounts - in other words, electricity can be generated in one location and credited toward consumption at another location - “in front of the meter”

How to compare energy systems

• Energy Efficiency = (useful energy out)/ energy in

  • Second Law of Thermodynamics: whenever energy is converted from one form to another in a physical or chemical change, we end up with lower quality or less useable energy (the entropy of an isolated system always increases - moves from order to disorder). The resulting low-quality energy usually takes the form of heat that flows into the environment.

• Life Cycle Analysis Community:

  • Look over entire lifespan from cradle to grave (raw material extraction to final disposal)

  • Compare based on GHGs or Land use intensity (m²/MWh

How many large and small dams are in the US

70,000 Large

more than 2 million small

What are dams used for

• Hydropower

• Flood Control

• Irrigation

• Recreation

• Public Supply

What influences dam power

• Height (head)

• Flow of river

• Efficiency of Equipment

How dams mess up river ecosystems

• Alter downstream flus of water and sediment

• Change water temps

• Create Barriers to upstream/downstream movement

• Reduced recruitment of riparian species

• Alter downstream food webs + productivity

• Ecosystem isolation

• Less biodiversity

Who in the US classifies dams

Federal Energy Regulatory Commission (FERC) – database of active hydropower licenses and control licensing process.

Low and high hazard dams

How we globally identify sizes of dams

•Micro (less than or equal to 0.1 MW)

•Small (>0.1 MW–10 MW)

•Medium (>10 MW–100 MW)

•Large (>100 MW–500 MW)

•Very Large (>500 MW)

•Mega (fluid definition – Hoover versus Three Gorges)

Storage Dam

Typically has hydraulic head + storage volume, long hydraulic residence time and control over rate of water release,

Run-of-river dam

Small hydraulic head and storage volume, short residence time and little (to no) control over water release rate.

Advantages of Hydro

• Low GHG

• Cheap

• 24/7 power

• Gives countries autonomy and remote areas access to power

• Close proximity to local energy source

• Renewable (not perpetual)

• Low maintenance

• Simple technology

• Parts are easy to get

Disadvantages of Hydro

• Habitat fragmentation

• Cutting fish distribution - harms fisheries +economies

• Lower quality and quantity of fish

• Increased temp

• Flood danger

• Seasonal variation

• Sedimentation and pollutants

• Geopolitical conflict

• Water table and erosion

• People/communities moved and justice issues

Hydraulic Residence Time

Cause of so much of dam impact. Affects:

• Sedimentation —> reduced sediment transport

• Chemical Transformation—> modified energy base

• Water Storage —> altered flow regime

• Thermal Stratification —> Altered thermal regime

• Dispersal Barrier —> Biotic Fragmentation

What do we need ecological classification of dams for

To inform removal and construction

Energy efficiency of hydro vs fossil fuel plants

hydro ~ 90% and fossil fuel is ~ 50%

Skidmore’s Small Hydro

• Gravity Renewables => Relevate Power

• How it works - policy

  • Remote net metered

  • Power Purchase Agreement (PPA)

    • a contract between two parties, one which generates electricity (the seller) and one which is looking to purchase electricity (the buyer). FERC regulates.

How much power could our current small hydro infrastructure add if actually used?

6 GW in US and 150 GW globally

What does Trading Dams mean

Removal of dams coupled with gain of hydro dams. New dam paired with dam removal.

Pumped Storage Hydro

• Pump water to higher elevation and hold it in reservoir

• The reverse turbine, let the water godown and then generate electricity.

Works in places with inconsistent rainfall or when it is at peak of the peak. Requires energy to pump water up the slope.