IB Design Technology 2.3.3 Design Guidance Notes

Lifecycle Energy Consumption and Battery Limitations

Introduction: Energy in Design and Everyday Life

Imagine purchasing a sleek new smartphone. While it feels lightweight and efficient, have you ever wondered how much energy was consumed to create it? From mining raw materials to manufacturing, shipping, and eventual disposal, the phone’s lifecycle tells a hidden story of energy use. Similarly, consider the battery that powers it, how does its design impact efficiency, reliability, and environmental sustainability? These questions are central to understanding lifecycle energy consumption and the limitations of modern energy storage systems, especially as designers strive to create more sustainable products.

Lifecycle Energy Consumption: Measuring Total Energy Use

What Is Lifecycle Energy Consumption?

Lifecycle energy consumption refers to the total energy used throughout a product’s lifecycle, from raw material extraction (cradle) to disposal (grave). This includes:

1. Production Energy: Energy used to extract, refine, and process raw materials, as well as manufacture the product.
2. Operational Energy: Energy consumed during the product’s use (e.g., charging a smartphone or fueling a car).
3. End-of-Life Energy: Energy required for dismantling, recycling, or disposing of the product.

Measuring Lifecycle Energy

To evaluate a product’s lifecycle energy consumption, designers and manufacturers use frameworks like cradle-to-grave analysis. This holistic approach considers every stage of the product lifecycle:

1. Cradle: Raw material extraction and processing.
2. Factory Gate: Energy used in manufacturing and transportation to the point of sale.
3. Grave: Energy for disposal, recycling, or reuse.

Embodied Energy: A Key Metric

Embodied energy is a measure of all the energy required to produce a material or product. It is expressed in terms of energy per unit weight, such as megajoules per kilogram (MJ/kg). For example:

• Aluminum: 155 MJ/kg (high due to energy-intensive extraction and processing).
• Timber: 10 MJ/kg (relatively low due to natural growth processes).

Challenges in Lifecycle Energy Measurement

Accurately measuring lifecycle energy consumption involves several challenges:

• Data Variability: Embodied energy values can vary due to differences in production methods or regional energy sources.
• Complex Supply Chains: Modern products often involve components sourced globally, making it difficult to trace energy use comprehensively.