Energy

Question 1

What is Energy

Answer 1

• In its simplest form, it is the ability to do work or bring about change.
• It is a fundamental quantity in both nature and human society, enabling the functioning of ecosystems and economies alike.

Question 2

What are energy carriers?

Answer 2

• They are substances or systems that store and transport energy in a form that can be later converted into useful work.
• Unlike energy sources, such as the sun or geothermal heat, energy carriers are typically processed or generated to make energy accessible and usable for human purposes.
• eg. biomass, coal, oil, natural gas

Question 3

What is energy system analysis?

Answer 3

• It is a critical field for understanding and optimizing energy use in a world of finite resources and increasing environmental constraints.
• This field seeks to address 3 key questions : what kind of energy is required, how much energy is needed, and how can energy systems be designed to be as cost-effective as possible.
• It gained significant traction after the oil crisis of the 1970s, which highlighted the vulnerabilities of over-reliance on specific energy sources and the need for diversification and strategic planning.

Question 4

How is energy a derived demand?

Answer 4

• energy is not consumed for its own sake but rather the services it enables.
• It underscores the fundamental relationship between energy use and human needs
• people do not need coal, they seek the outcomes energy provides, such as cooked food, clean water and illumination.
• This demand extends to broader societal and industrial needs, including transportation, communication and manufacturing.

Question 5

What are the renewable energy sources?

Answer 5

• They are forms of energy derived from the natural processes that are regenerative, effectively inexhaustible within a human timeframe, and cannot be depleted under normal usage conditions.
• Unlike fossil fuels which are finite and take millions of years to form, renewable energy sources replenish naturally and consistently, making them a cornerstone for sustainable energy systems.

Question 6

What are some limitations of renewable sources of energy?

Answer 6

1. Initial costs : High upfront costs for equipment, installation, and maintenance
2. Weather dependency : eg. solar power are less effective in bad weather. poor weather can prevent solar power generation
3. Space requirements : require a lot of space, not everyone can build a wind farm or put a solar panel on their roof
4. Unreliable electricity production : can be unreliable. it’s important to find ways to use it without straining the power supply network
5. Storage capabilities : Although some electricity can be stored, it’s not yet possible to store it on a large scale

Question 7

What are some advantages of renewable sources of energy?

Answer 7

1. Reduced pollution: like solar and wind power produce little to no emissions of carbon dioxide and other pollutants
2. Climate change mitigation: help fight climate change by reducing greenhouse gas emissions
3. Cleaner air and water: help improve air and water quality
4. Affordable energy
5. Inexhaustible: sources like sunshine, wind, tides, and biomass won’t run out
6. Less maintenance: technologies like solar panels require less maintenance than traditional fuel systems

Question 8

What are conventional energy sources?

Answer 8

• those that rely on well-established, commonly used technologies for extraction, generation and utilization.
• these sources include fossil fuels such as coal, oil, and natural gas, as well as hydro power in certain contexts
• they have been the backbone of global energy systems for decades, supporting industries, transportation, and household needs.
• eg. coal-fired power plants, oil refineries and gas turbines

Question 9

What are non-conventional energy sources?

Answer 9

• • They rely on newer, less widely adopted, or emerging technologies.
• These include solar, wind, tidal and geothermal energy, as well as advanced systems like hydrogen fuel cells and biomass gasification.
• for eg. the use of photovoltaic cells to harness solar energy or wind turbines to generate electricity represents the non-conventional
• While these energy sources have gained significant attention in recent years, they are still evolving in terms of efficiency, scalability and cost-effectiveness compared to their conventional counterparts.

Question 10

What are commercial energy sources?

Answer 10

• those that are traded in the market and have a clearly defined market price.
• these sources and typically part of formal energy markets and supply chains and are often associated with industrial, commercial and large-scale household use.
• eg. coal, petroleum, natural gas, electricity.

Question 11

Examples of commercial energy sources :

Answer 11

1. coal is widely used in thermal power plants and heavy industries. it is purchased at a market price and it cost is influences by global demand and supply
2. petroleum and its derivatives such as gasoline and diesel, are essential for transportation and are bought and sold at fluctuating market prices influenced by geopolitical factors
3. electricity is generated using a variety of energy sources like fossil fuels, hydropower and is sold to consumers based on regulated market-driven tariffs

Question 12

What are non-commercial energy sources?

Answer 12

• those that do not have a market price and are often freely available in rural or informal settings
• these sources are typically gathered or produced locally, often at zero or minimal private cost and are primarily used for subsistence purposes
• eg. fuelwood, dung-cakes, and agricultural residues.

Question 13

Examples of non-commercial energy sources:

Answer 13

1. fuelwood, which is commonly found from nearby forests or plantations, is a primary source of energy for cooking and heating in rural areas
2. dung-cakes, made from dried animal dung, are widely used as cooking fuel in villages and small towns
3. agricultural residues, such as crop stalks, husks and straws, are often repurposed as fuel for household use or small-scale rural areas

Question 14

Limitations of non-commercial energy sources

Answer 14

1. lack of proper data
2. health and environmental concerns
3. labor intensive collection
4. inefficiency

Question 15

What are fossil fuels?

Answer 15

• hydrocarbons formed from the remains of living organisms that existed millions of years ago.
• these fuels are extracted from the earth’s crust and are primarily used as energy sources
• petroleum, coal and natural gas which powers industrial growth, transportation and global economies

Question 16

advantages of fossil fuels in the earlier decades

Answer 16

1. cost-effective and economical
2. abundant
3. easily accessible
4. high energy output
5. affordable

Question 16

limitations of fossil fuels

Answer 16

1. geopolitical influence
2. price volatility
3. environmental costs
4. shifts in energy policy

Question 17

key challenges in electricity systems

Answer 17

1. high costs of energy storage
2. immediate consumption requirement
3. supply-demand balance imperative

Question 18

primary sources of energy products

Answer 18

• raw, naturally occurring resources harvested directly from the environment
• unprocessed and require no chemical transformation before use as energy carriers
• fossil fuels, biomass, renewable flows, nuclear like uranium ore

Question 19

secondary sources of energy products

Answer 19

• processed or converted forms of energy derived from the primary sources
• human-engineered transformation to make energy usable for specific applications
• created through mechanical, thermal or chemical processes
• eg. electricity from coal, refined petroleum products like gasoline