Material Selection, Costs and Energy Production Methods
Engineers do not just design a product, they choose the right material and think about energy. Learn how to weigh cost, availability, lifespan and maintenance, and how energy production methods shape a design.
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Choosing wisely
An engineer does not just design a shape. They choose the right material and think about how the product will be powered and made. The best choice balances cost, availability, how long it must last and how much upkeep it needs, and it considers the energy behind it. This module shows how engineers weigh it all.
Four selection factors
Engineers weigh these four things whenever they pick a material.
Match the factor
- Cost
- Availability
- Lifespan
- Maintenance
- Can we afford this material?
- Can we get enough of it, on time?
- How long must the product last?
- How much upkeep will it need?
Why reject it?
A metal is cheap but rusts quickly in the rain. For an outdoor gate, why might an engineer reject it?
- It would not last long enough outdoors
- It is too expensive
- It is too rare to find
- It needs no maintenance
Renewable or not?
How a product is powered or made matters. Energy sources fall into two groups.
Match the energy source
- Wind
- Solar
- Coal
- Nuclear
- Renewable, from moving air
- Renewable, from sunlight
- Non-renewable fossil fuel
- Non-renewable, from a limited fuel
There is no perfect material
A material is rarely best on every factor at once. Engineers weigh cost, availability, lifespan and maintenance against what the user needs, and choose the best balance for the job.
Cost, durability and energy
When choosing a material, engineers weigh its _____ against how long the product must last, its _____. They check the material is _____ when needed. Products powered by _____ energy, such as wind and solar, will not run out, unlike _____ fuels.
Renewable sources
Which of these are renewable energy sources? Choose all that apply.
- Wind
- Solar
- Tidal
- Coal
- Natural gas
Real selection factors
Tap the two things that are real material selection factors.
- How much the material costs.
- How long the product must last.
- The favourite colour of the designer.
- Whether it looks trendy this year.
Selecting a material
Put the material selection process into a sensible order.
- Decide what the product must do
- List the properties it needs
- Check which materials have those properties
- Compare their cost and availability
- Choose the best material for the job
Work out the material cost
A part needs 3 kilograms of aluminium. Aluminium costs 4 pounds per kilogram. What is the material cost in pounds?
Design decisions
You are choosing materials and energy for an outdoor product. Make the best decision at each stage.
- You are designing an outdoor bridge handrail. Which property matters most?
- Two suitable metals cost the same, but one is hard to get hold of. Which do you choose?
- The product will run all day. Which energy source lowers its carbon footprint?
Material and energy, chosen together
Explain how an engineer chooses a material for a product, and why the energy source used to power or make it matters.
- Name two factors that affect material choice
- Explain how cost and lifespan are balanced
- Explain why renewable energy might be preferred