Welcome to Energy and Energy Resources!
In this chapter, we explore the "fuel" that makes technology work. Whether it is a smartphone in your pocket or a bicycle on the road, everything requires energy to function. For Design and Applied Technology (DAT) students, understanding energy isn't just about science; it is about making smart choices when designing products to ensure they are efficient, useful, and kind to our environment.
1. Energy Sources and Natural Resources
Everything starts with where we get our energy. We generally divide these into two main categories based on how long they last and where they come from.
Non-Renewable Energy
These are resources that exist in finite (limited) amounts. Once we use them, they are gone forever—or at least take millions of years to replace. Examples include fossil fuels like coal, oil, and natural gas. While they are currently very common, they lead to environmental concerns and will eventually run out.
Renewable Energy
These come from natural processes that are constantly replenished. They are key to sustainable development because they don't run out.
• Solar Energy: Captured using solar panels (photovoltaic cells).
• Wind Energy: Captured by turbines.
• Hydroelectric: Using the power of moving water.
Quick Review: Designers today are moving toward renewable sources to meet environmental responsibility goals and promote green design.
2. Energy Consumption in Product Operation
When you design a product, you must consider how much energy it "eats" while it is being used. This is called energy consumption.
Why does consumption matter to a designer?
1. Portability: If a product uses a lot of energy, it needs a bigger battery, which makes it heavier (think of a laptop vs. a calculator).
2. Cost: High energy consumption means it is more expensive for the consumer to run (like an old, inefficient air conditioner).
3. Heat: Energy that isn't used for the main task often turns into "waste heat," which can damage components or require loud cooling fans.
Calculating Power
In the "Electronics" section, we use a simple formula to understand how much power an electrical product is using:
\(P = V \times I\)
Where:
• \(P\) is Power (measured in Watts)
• \(V\) is Voltage (measured in Volts)
• \(I\) is Current (measured in Amperes)
Analogy: Think of electricity like water flowing through a pipe. Voltage is the pressure, and Current is the amount of water moving. Power is the total work that water can do!
3. Design Impact: How Energy Changes the Design
Energy requirements don't just happen at the end; they change the entire design process. If you know a product must be "green," your design choices will change in these ways:
Material Selection
Designers choose materials that require less energy to process. For example, recycling aluminum uses only about \(5\%\) of the energy required to make new aluminum from raw ore!
Efficiency
A good design minimizes energy waste. For example, in mechanical systems, using ball bearings instead of plain bushings reduces friction. Less friction means less energy is wasted as heat, making the machine more efficient.
Product Life Cycle
We must consider resource conservation. This means designing products that can be easily repaired or recycled, so the energy "invested" in making them isn't wasted when the product reaches its end of life.
4. Case Studies: Energy in Action
The syllabus highlights two specific cases to help us understand these principles.
Case A: The Bicycle
A bicycle is a perfect example of a human-powered system.
• Input: Chemical energy from the rider (food).
• Process: The mechanical systems (chain, sprockets, and pedals) convert this into motion.
• Design Impact: To save the rider's energy, designers use lightweight materials (like aluminum or carbon fiber) and aerodynamic shapes to reduce "drag" (air resistance).
Case B: Beverage Containers
Think about a soda can versus a glass bottle.
• Production Energy: Creating a plastic (PET) bottle requires different energy levels compared to a glass bottle or an aluminum can.
• Transportation: A heavy glass bottle requires more fuel (energy) to transport than a light aluminum can.
• Recycling: How easy is it to get the material back? Aluminum is highly "energy-efficient" to recycle, making it a popular choice for sustainable design.
5. Innovation and Technology
It is important to distinguish between two key terms often used when talking about new energy solutions:
• Invention: Creating a brand-new energy-saving device that never existed before.
• Innovation: Taking an existing idea (like a battery) and making it much better or applying it in a new way (like putting that battery into an electric car).
Key Takeaway: Modern technology focuses on miniaturisation (making things smaller) and advanced production techniques to save energy and improve our quality of life.
Summary Checklist
☐ Renewable vs. Non-renewable: Do you know the difference?
☐ Energy Consumption: Can you explain why high energy use might be a "design flaw"?
☐ Design Impact: How does the need for energy efficiency change the materials we use?
☐ Power Formula: Remember \(P = V \times I\) for basic electrical consumption.
☐ Sustainable Development: Always think about the "green" factor in your design brief!