A more sustainable and circular product-service system of rechargeable power banks around London underground and bus stations for busy commuters

The Environmental Issue of Portable Power Banks

Portable power banks can be a convenient way to charge electronic devices when you're on the go, but they can also have a negative impact on the environment if not disposed of properly. Potential environmental issues with portable power banks comes from three aspects:

  1. Raw materials: Portable power banks are made from a variety of materials, including metals and plastics, which can be damaging to the environment if not extracted and manufactured responsibly.

  2. E-waste: Like all electronic devices, portable power banks eventually reach the end of their useful life and need to be disposed of. If they are not properly recycled, they can contribute to the growing problem of e-waste, which can release hazardous substances into the environment.

  3. Energy consumption: The production and use of portable power banks requires energy, which can contribute to greenhouse gas emissions and climate change.

To minimize the environmental impact of portable power banks, it's important for design engineers to design ones that are made from sustainable materials, recycle them properly when they reach the end of their useful life.

More importantly, as services like power bank stations were booming at 2021 globally, our task was to design a more circular resource management system for this type of electronic products.

A typical power bank is made of electronics, batteries, and outer casing with connecting parts

Customer Pain Points

While environmental sustainability is our main focus, we should acknowledge existing customer pain points with power banks so that a new product solution could be designed catering to their interests and needs.

For this project, the process of user research wasn't assessed but customer discovery is still an integral phase of sustainable design engineering because the total market size will determine the system's impact and influence the return of investment. Therefore, we conducted desk research and made observations from a small sample of city commuters (mainly students and their relatives), and decided to target four pain points:

  1. It's very inconvenient when their phone or tablets runs out of power in exceptional cases.

  2. Commuters find it difficult to find charging points during journeys.

  3. Commuters do not want to bring bulky adapters or personal power banks with them every day.

  4. Battery capacity degrades over time causing redundant power banks piling at home.

Customer pain points: 1.Forget charging before left home. 2. Hard to find charging points during journeys. 3. Do not want to bring bulky power banks on-the-go. 4. Degrading battery capacity over time causes redundant power banks piling at home.

FMCGs and Five Re-use Models

What's FMCGs? It refers to Fast Moving Consumer Goods (FMCGs), which are mass produced products that conveniently and recurrently meet consumers' demands (Zeeuw van der Laan et al., 2019). As design engineers, we adapt the reuse frameworks to help us think and design products to reduce wastes by use components of an 'obsolete' product again.

The five reuse models were proposed by researchers from Dyson School of Design Engineering after selecting and analysed 92 reuse offerings in the FMCG sector, and could be categorized into exclusive and sequential reuse models distinguished by the resource ownership. In the case of rechargeable power banks, Model 4 is the most appropriate because customers won't take ownership of the product, and reuse preparation would be industrially set-up focusing on the circular usage of this services (charging mobile electronic appliances).

Stakeholder Engagement

Our interventions take careful considerations of a service model to reduce, material choices of durable alternatives to reuse, and the industrial capacity to recycle. By engaging multiple stakeholders within the system and collaborating with external regulator (and even competitors), U-Charge system is designed to benefit everyone.

Our Final Proposal

The design outcome of this project is a proposed circular product-service system as illustrated by the picture above. Multiple stages such as the production and consumption sub-circles for resource management were presented in detail. Environmental considerations were explicitly given.

Design interventions would take place at different stages of resource management, such as using green power sources innovatively (a step-charging system), bio-degradable package design, design for disassembly and reuse strategies, and user behavioural guide through user interface design.

In a nutshell, U-Charge power stations would notify the service provider when its power bank battery life has come to an end and recycle the power bank in UK's existing facilities.

Evaluation and Future Outlook


What sets us apart from those is the sustainable design and extended life cycle in our product. This is a cornerstone of U-Charge’s ethics. With a huge potential market available in the UK, our design strive to not only make our power banks, but also the entire U-Charge system attractive to users and viable for business in a near future.

In our proposal, U-Charge stations will be based in Edinburgh, Manchester, Cardiff and London. In order for the system to work best, each U-Charge station on the map would represent around 15 stations. To satisfy our need for a circular resource flow, there will be two repair workshops for general repair of recovered power banks. They will be located in the north and the south. There will be one specialised battery recycling factory located in the centre of the UK. This is because we estimate that battery repairs will be less common than repairs to the exterior of the batteries that can be caused by users dropping them. By implementing this system when a charger needs to be repaired, less distance will be travelled, therefore reducing the environmental impact.


The biggest barrier to our proposed interventions would be the large amount of investment needed for industrial capacity upgrading (estimated minimum £15 million for recycling captial implementation). Our proposition is based on the assumption that UK government would take experts’ advice and take initiative to lead the change. We believe our intervention strategies can take effect within the next 5 years.


We are not taking a winner-gets-all market expansion to rule out competitors. Instead, we would promote our design to exisiting competitiors and provide product end-life recovery service so that the e-waste can be treated together in the central distribution and recycling site. Our power bank is intelligently designed to be future-proof (i.e. wireless charging technology), durable (longer lifetime), and sustainable (design for reuse and repair). Hence, we are confident that we have a good position within the current system.