Energy and Sustainability
Energy and Sustainability
Energy generation, storage, and sustainability are central themes in AQA GCSE Design & Technology. You must understand how products use energy, the environmental impact of energy sources, and how designers can reduce a product's ecological footprint.
Energy Sources
Energy sources are classified as renewable (replenished naturally) or non-renewable (finite, will eventually run out).
| Source | Type | How It Works | Advantage | Disadvantage |
|---|---|---|---|---|
| Solar | Renewable | Photovoltaic cells convert sunlight to electricity | Free fuel, no emissions in use | Intermittent, expensive panels |
| Wind | Renewable | Turbines convert kinetic energy of wind | No fuel costs, scalable | Noise, visual impact, intermittent |
| Hydroelectric | Renewable | Flowing water drives turbines | Reliable, long lifespan | Requires dam, habitat disruption |
| Tidal | Renewable | Movement of tides drives turbines | Predictable, reliable | High setup cost, limited locations |
| Biomass | Renewable | Burning organic matter releases heat energy | Uses waste materials | Produces CO2, land use issues |
| Nuclear | Non-renewable | Fission of uranium atoms releases heat | Very high output, low CO2 | Radioactive waste, decommissioning costs |
| Fossil fuels (coal, oil, gas) | Non-renewable | Combustion releases heat energy | Reliable, established infrastructure | CO2 emissions, finite supply, pollution |
Energy Storage and Distribution
- Batteries store electrical energy chemically (e.g. lithium-ion in phones, lead-acid in cars)
- Kinetic energy recovery systems (KERS) capture energy during braking and reuse it
- The National Grid distributes electricity from power stations to consumers via high-voltage transmission lines
Sustainability in Design
Sustainability means designing products that meet current needs without depleting resources for future generations. The 6 Rs framework helps designers reduce environmental impact:
| R | Meaning | Example |
|---|---|---|
| Reduce | Use less material or energy | Thinner packaging, energy-efficient motors |
| Reuse | Use the product or components again | Refillable water bottles, second-hand furniture |
| Recycle | Process waste materials into new products | Aluminium cans melted and reformed |
| Refuse | Avoid using harmful materials or processes | Refusing single-use plastics |
| Rethink | Redesign to be more sustainable | Modular phones with replaceable parts |
| Repair | Fix rather than replace | Repair cafes, replaceable components |
Life Cycle Assessment (LCA)
An LCA evaluates the environmental impact of a product from cradle to grave. The stages are:
1. Raw material extraction — mining, logging, drilling
2. Processing and manufacture — energy used, waste generated
3. Transportation and distribution — carbon footprint of logistics
4. Use and maintenance — energy consumption, consumables
5. End of life — disposal, recycling, landfill, incineration
Designers use LCAs to identify where the greatest environmental impact occurs and make improvements. For example, switching from virgin plastic to recycled plastic reduces the impact at stage 1.
Carbon Footprint
A product's carbon footprint is the total amount of greenhouse gases (measured in CO2 equivalent) emitted throughout its lifecycle. Ways to reduce it include:
- Using local suppliers to cut transport emissions
- Selecting low-energy manufacturing processes
- Designing for disassembly so materials can be separated for recycling
- Choosing materials with lower embodied energy
Eco-Design Strategies
- Design for disassembly — using snap fits instead of adhesives so parts can be separated
- Design for longevity — high-quality materials and timeless aesthetics
- Lightweight design — less material means less energy in transport
- Biodegradable materials — products that break down naturally at end of life
- Closed-loop recycling — waste from production is fed back in as raw material
Exam Tips
- Always link energy sources to specific products or systems (e.g. solar panels on a garden light)
- When asked about sustainability, structure your answer around the 6 Rs and give examples
- LCA questions often ask you to evaluate which stage has the greatest impact — justify your answer
- Know the difference between renewable and non-renewable — this is a common short-answer question
- If asked to suggest improvements, use technical vocabulary: "embodied energy", "closed-loop", "cradle to cradle"
Key Definitions
- Embodied energy: The total energy required to extract, process, manufacture, and deliver a material or product
- Cradle to cradle: A design philosophy where products are made from materials that can be fully recycled into new products of equal quality
- Finite resource: A material that exists in limited supply and cannot be renewed within a human timescale
- Carbon neutral: A process where the net carbon emissions are zero, often achieved through offsetting