Energy Defined
Energy = capacity to do work, move things, or cause changes of state
3 Types of Energy
3 types of energy:
Kinetic = when matter is moving (e.g. wind blowing, streams flowing, heat, electricity)
Potential = energy not in use at this moment, but that could be released (e.g. water stored behind a dam, tank of gasoline, lump of coal)
Electromagnetic radiation = waves of energy that are emitted and passed through space (e.g. sunlight, x-rays)
Nuclear Energy
Nuclear energy (a form of potential energy until it is released)
A spontaneous change in the nucleus of an atom releases energy
Most commonly done by fission (i.e. split the nucleus)
First Law of Thermodynamics
New energy cannot be spontaneously created
We can take existing forms of energy and cause it to change form or transfer it from one place to another
Humans cannot "make" new energy
We also cannot destroy energy (but we certainly can and do waste it)
If we can't make energy, from where can we get it?
The Sun
Matter (e.g. uranium)
Second law of thermodynamics
Second law of thermodynamics:
When energy changes from one form to another, there is a loss of efficiency
We can never gain additional energy when we change it from one form to another
In fact, when it changes form, we cannot even end up with an equal amount of energy
Some energy is always wasted with each transformation
There is never perfect efficiency
Examples of Law #2 of thermodynamics in practice
<25% of the energy in gasoline propels a car; the rest gets lost to heat escaping the engine block, exhaust pipe, etc
Traditional incandescent bulbs use only about 5% of the incoming electricity to produce light, the rest is wasted as heat
Global energy use by source, since 1800
Global primary energy consumption by source
Primary energy is calculated based on the 'substitution method' which takes account of the inefficiencies in fossil fuel production by converting non-fossil energy into the energy inputs required if they had the same conversion losses as fossil fuels
Energy consumption by source, since 1965
Primary energy consumption is measured in terawatt-hours (TWh)
An inefficiency factor (the 'substitution' method) has been applied for fossil fuels, meaning the shares by each energy source give a better approximation of final energy consumption
Global per capita energy consumption, selected countries
Per capita primary energy consumption by source, 2022
Primary energy is calculated based on the 'substitution method' which takes account of the inefficiencies in fossil fuel production by converting non-fossil energy into the energy inputs required if they had the same conversion losses as fossil fuels
Fossil fuel share of global energy mix >80%
Primary energy consumption from fossil fuels, nuclear and renewables, World
The breakdown of primary energy is shown based on the 'substitution' method which takes into account inefficiencies in energy production from fossil fuels
Coal
Used primarily as fuel to generate electricity
Abundant in North America, Asia, Australia, Europe & Russia
Scarce in Africa and South America
Reserves of coal in 2018, by continent
Conventional oil & natural gas reserves
Oil has a variety of uses
Most common use = transportation
Also used as a feedstock for plastics and a wide range of synthetic products
Can also be burned for heating
Abundant in Middle East, the Americas
Limited reserves in Europe, Africa, and Asia
Important global energy patterns
Consumption of energy is growing most rapidly in Asia
Asia has low reserves of oil, natural gas, but lots of coal
North America has large reserves of all types of fossil fuel, and has high rates of consumption
Middle East has large reserves of oil and gas, relatively few people (so it exports most of its production)
Russia has lots of natural gas, coal (and exports much of it to Europe, Asia)
Western Europe has coal, but must import most oil & natural gas
Central & South America have oil, some natural gas
Africa has overall limited reserves of fossil fuels of all types and these tend to be concentrated in only a few countries: Libya, Nigeria, Algeria, Angola
Environmental impacts of fossil fuels
Impacts occur at the time/place of extraction, transportation, and consumption
Two types of coal mines: shaft and open pit
Shafts are dangerous workplaces
Open pit mines are safer, easier, and cheaper, but damaging to forests, downstream waterways, and biodiversity
Mining releases large amounts of sediments, potential toxins, and metals
Mountaintop coal mines pose a risk of water contamination downslope and flooding for communities downstream
Pipeline spills and rail accidents also contribute to environmental damage
Coal emits more greenhouse gases per unit energy than other fossil fuels
Coal emits more air pollutants than other fossil fuels
Impacts vary depending on the location of extraction and transport
Offshore oil rig spills and tanker ship spills harm wildlife and contaminate water and coastlines
Onshore rigs and leaky pipelines can contaminate soil and rivers
Examples of spills include the Deepwater Horizon oil spill and pipeline accidents in Kalamazoo and Lac-Mégantic
Oil refineries generate contaminated wastewater and air pollution
Tar sands contain oil in tar-like material called "bitumen"
Extraction methods include open-pit mining and injecting hot steam into the ground
Upgrading facilities remove sand from the bitumen and make it more liquid for transportation
Alberta tar sands are inefficient, expensive, and polluting
Despite the negative impacts, companies continue tar sands production for financial reasons
Remediation involves removing toxins, capping and sealing pipes and wells, and revegetating the site
Companies in Canada often delay or avoid remediating abandoned mines and wells, leading to a large number of unremediated sites
There are currently 170,000 abandoned oil wells in Alberta, with a cleanup cost estimated at $40-70 billion
Consuming oil and natural gas releases greenhouse gases and air pollutants
Current energy supply in Canada includes coal, crude oil, natural gas, nuclear, hydro, and other renewables
There is a need to increase the supply of renewable energy
Primary energy consumption is dominated by fossil fuels
The goal is to reduce fossil fuel consumption and increase the share of renewables by 2050
Turbines transform kinetic energy into a more usable form, either performing mechanical work or generating electricity
Turbines can be powered by moving water or moving air
Electrical generators use magnets and coiled wire to generate electrical current as the turbine shaft turns
Thermal generators use pressurized steam from boiling water to turn the turbine shaft, commonly fueled by natural gas or coal
Nuclear generators use a nuclear reaction to generate heat, which boils water to create steam and turn the turbine shaft
Nuclear fission inside a reaction chamber releases energy and produces radioactive by-products
Chain reactions involving neutrons and uranium-235 sustain the nuclear reaction
Nuclear generating facilities are most common in countries with advanced technology sectors
Producing fuel is not easy and the process is very expensive
Uranium is the most common nuclear fuel
Excavation and grinding of rock containing uranium
Chemicals applied to separate uranium from other material
Damages surface land cover (forests, soil)
Mine tailings (wastewater) are toxic and not easily disposed of
Nuclear reactor waste is radioactive and harmful for centuries
Waste is usually stored on-site
Initially in pools of water
Later in cement bins
Nuclear accidents
Chernobyl, Ukraine, 1986
Significant design flaws in the nuclear plant
Radioactive fallout renders immediate vicinity dangerous for many years
f*ckushima, Japan, 2011
Significant design flaws in the nuclear plant
Radioactive fallout renders immediate vicinity dangerous for many years
