Comprehensive Study Notes on Renewable and Non-Renewable Energy Resources

Fundamental Distinctions: Renewable and Non-Renewable Energy

Energy resources are categorized into two primary divisions based on their replenishment rates: non-renewable and renewable resources. Non-renewable resources are defined as those that will not replenish themselves within a human lifetime. Once the entirety of a non-renewable resource is consumed, the process for it to form again could span billions of years, making it functionally finite. Primary examples include fossil fuels found deep within the ground such as coal, oil, and natural gas. Another significant non-renewable source is nuclear power, which relies on uranium. While these resources are noted for being easy to use and providing an efficient form of energy, they carry significant environmental dangers. The utilization of these materials involves heating, which produces polluting by-products. It is predicted that these sources may run out very soon without significant lifestyle changes.

Renewable resources, by contrast, are those that can be utilized repeatedly without a negative effect on the environment. Solar energy is a prominent example, as the sun produces enough energy to power the entire global population. Theoretically, establishing enough solar panels could solve the non-renewable energy crisis; however, the sun does not shine consistently in all locations, leading to inefficiencies. Wind energy is similarly renewable but suffers from inconsistent flow, making it another less efficient source. Hydro energy utilizes the flow of water through dams, which is efficient but expensive to construct. Geothermal energy harnesses heat from below the Earth’s surface to produce steam to spin turbines; this is also efficient but involves high setup costs. Biomass is the final common renewable resource, involving the burning of plants, crops, and animal waste to create heat and steam for turbine power.

The Science and Mechanics of Solar Energy

Solar energy refers to the energy emitted by the sun's rays, a resource humans have utilized for thousands of years in the form of thermal energy (for warmth and drying clothes) and light energy (for visibility). Modern technological advancements allow for the conversion of solar radiation into electricity to power electronics, machines, and electric vehicles. Solar energy is considered an infinite and renewable resource because the supply cannot be exhausted.

Solar energy is harnessed through solar panels, which consist of numerous connected solar cells. These solar cells have two distinct sides: one side with positively charged electrons and one side with a negative charge. When sunlight strikes the cell, the energy knocks electrons loose, causing them to flow from one side to the other, thereby creating an electrical circuit. This harnessed energy is stored as potential energy in batteries to be used on demand. Individuals can plug electronics into a solar panel setup to utilize this flow of electrons.

There are specific benefits and drawbacks to solar energy. The benefits include the fact that it is a renewable source we will not run out of, it produces no greenhouse gases or air pollution, and once homes are set up, the electricity is essentially free to use. The drawbacks include the limitation that energy can only be collected during sunny periods, as cloudy or rainy days slow down storage. Additionally, storing energy requires batteries that do not decompose and will eventually end up in landfills. The initial cost to install solar panels is also very high.

Wind Energy: Atmospheric Pressure and Power Generation

Wind is defined as the movement of air moving from regions of high pressure to regions of low pressure. This movement is driven by temperature changes: when gases in the air are warmed, they spread out, resulting in higher pressure. Conversely, when air is cooled, gas particles move closer together, resulting in lower pressure. Wind energy is the harnessed movement of this air, which can be used to fly kites, move sailboats, or spin wind turbines.

A wind turbine functions similarly to a windmill. When wind energy spins the turbine, it connects to a generator. This generator converts mechanical energy into electrical energy by forcing electrons through an electrical circuit. In Canada, wind energy is the second most utilized renewable resource, generating approximately $3.5\%$ of the nation’s electricity. This trails behind moving water, which generates $59\%$

Benefits of wind energy include its status as a clean energy source that does not produce greenhouse gases and is infinite. Once the turbine is set up, the energy is free, and the turbines do not occupy significant ground space. Drawbacks include the danger they pose to birds and bats that fly into blades, and their noise level, which often results in them being built in rural areas. They are expensive to set up and are unpredictable, only generating power when the wind blows. If the wind stops for long periods, stored energy reserves may run out, and some find that they interfere with scenic views.

Hydroelectric Energy: Harnessing Water Currents

Hydro energy is harnessed from the movement and flow of falling water, typically observed in the currents of streams or rivers that send water downhill. Utilizing watermills for work dates back to the $3^{\text{rd}}$ century with the Greeks, who used moving water to spin a pipe connected to machinery. In modern contexts, a hydroelectric dam blocks the flow of water to create a reservoir, which acts as a lake. The water stored at high altitudes in these reservoirs represents potential energy.

To generate electricity, an intake at the bottom of the concrete dam wall allows water to travel down a pipe called a penstock. This consistent flow spins a turbine, which then generates electricity. Hydroelectricity is a major power source in Canada, where the government has built over $15,000$ dams to reduce reliance on fossil fuels. Hydro energy creates $59\%$ of all electricity used by Canadians, making Canada the second-largest producer of hydroelectricity in the world, following only China.

Benefits of hydro energy include being a renewable source that will not be exhausted and being a clean source with no greenhouse gas emissions. It is considered the most reliable renewable energy because water flow is constant. Drawbacks include the impact on fish populations due to the disruption of natural water flow and the fact that dams can only be built in specific locations where water already flows. Additionally, many of these sites are remote, making it difficult to transport power to major cities, and the cost of building dams is extremely high. Reliability can also be compromised in the event of a drought.

Biomass and Tidal Energy: Emerging Renewables

Biomass energy is derived from plant and animal materials, including wood, crops, and animal waste. This material can be processed through an industrial biomass boiler system involving a fuel store, wood chipper, and an auger and agitator. The biomass is converted into electricity or used as fuel for heating via hot water and a buffer tank. Advantages include its status as a renewable resource (as crops and trees can be replanted), its ability to reduce waste by repurposing materials, and its global availability. Disadvantages include the limited supply of waste, the release of harmful pollutants when burned, and the high cost of power plant construction.

Tidal energy utilizes the natural rise and fall of ocean tides to turn turbines and create electricity. This source is renewable because tides are constant and highly predictable, allowing for accurate power generation planning. It also produces no atmospheric emissions. However, it is limited to specific geographic areas with large tidal ranges, can disrupt marine life ecosystems, and is expensive to build and maintain.

Geothermal Energy: Generating Power from Earth's Heat

Geothermal energy systems utilize the heat from within the Earth to generate power. The process begins by injecting water into the ground toward hot rocks heated by magma. This heat converts the water into steam. The steam then travels upward to turn a turbine and generator, creating electricity. After the steam has been used, it is sent to cooling towers where it is cooled back into a liquid state. This "return water" is then re-injected into the well to repeat the cycle.

Fossil Fuels: Coal, Oil, and Natural Gas

Fossil fuels are energy sources formed from the remains of plants and animals that lived millions of years ago. The three most common types are coal, oil, and natural gas. These are primarily used to generate electricity, power vehicles, and provide domestic heating. Data on $CO_2$ emissions by source indicates that Oil accounts for $46\%$, Coal accounts for $35\%$, and Gas accounts for $19\%$.

Advantages of fossil fuels include their current abundance and ease of extraction using modern technology. They are highly reliable as they can generate power regardless of weather or time of day, and they are powerful, packing high energy density into a small amount of material. Disadvantages are significant: they are non-renewable and will eventually be exhausted; they contribute to climate change by releasing carbon dioxide and other pollutants; and the extraction process is dangerous, carrying risks of oil spills and coal mine accidents.

Nuclear Power: The Energy of the Atom

Nuclear energy is produced through nuclear fission, which is the process of splitting a uranium atom into two smaller atoms. This releases heat from the nucleus of the atom, which is then used to create steam for power generation. Nuclear energy is considered non-renewable because it relies on uranium, a finite resource.

In Canada, there are $19$ nuclear reactors, with $18$ located in Ontario and $1$ in New Brunswick. Nuclear power provides $15\%$ of Canada's energy needs and approximately $10\%$ of energy consumed worldwide. Advantages of nuclear power include its land efficiency, as it uses $450$ times less land than solar energy for the same output. It is a stable, consistent source that operates around the clock ($100\%$ of the time), whereas solar and wind may only produce energy $10-30\%$ of the day. It also emits no greenhouse gases during generation. Disadvantages include the risk that raw materials could be used for nuclear weapons, the potential for catastrophic accidents, and the production of radioactive waste that remains dangerous for thousands of years and requires careful disposal.

Energy Production and Profiles in Alberta, Canada

Alberta’s energy profile is heavily dominated by fossil fuels, which contribute approximately $66\%$ of the total energy supply, driven by the province's rich deposits of oil sands, natural gas, and coal. The specific breakdown of energy usage in Alberta is as follows: Natural Gas ($39\%$), Coal ($27\%$), Oil ($14\%$), Wind ($7\%$), Biomass ($5\%$), Geothermal ($5\%$), Hydro ($2\%$), and Solar ($1\%$).

Significant facilities in the province include the Brazeau Dam on the Peace River for hydroelectric power, and the Pincher Creek Wind Farm in the southern region for wind power. Biomass energy is also utilized at facilities like the Whitecourt Power biomass plant, which converts waste into electricity and heating fuel.

Individual Responsibility and Energy Conservation

Responsible energy use involves intentional actions to reduce consumption and waste. Examples of responsible energy behavior include turning off lights when leaving a room, biking to work instead of driving, playing outside rather than using electronics, and wearing sweaters or using blankets rather than turning up the heat. Opening windows for a breeze instead of using air conditioning and carpooling to the same workplace are also examples. Conversely, irresponsible behaviors include leaving electronics or cars running while not in use, keeping the house excessively warm in winter, and leaving the refrigerator door open for extended periods.

Questions & Discussion

1) Describe how geothermal energy works based on the diagram. Geothermal uses the heat in the earth to heat up injected water. The water comes up as steam and then turns turbines which spin generators. The generators produce electricity and the extra steam is cooled off in cooling towers. The water is then injected again.

2) What are fossil fuels? Name the 3 most common and how they are used. Fossil fuels are the remains of plants and animals that lived millions of years ago. The three most common are coal, oil, and natural gas. They are used to generate electricity, power vehicles, and heat our homes.

3) What are the advantages and disadvantages of fossil fuels? Advantages include being easy to get, abundant, reliable, and powerful. Disadvantages include being non-renewable, causing pollution, and being dangerous to extract.

4) Multiple Choice: Fossil fuels come from the remains of? Organisms.

5) Multiple Choice: Which is a type of fossil fuel? Oil.

6) Multiple Choice: Are fossil fuels reliable? Yes.

7) Multiple Choice: Burning fossil fuels releases? Carbon Dioxide.

8) Multiple Choice: Fossil fuels are ________ to extract. Dangerous."