Creating a Circular Economy Through Device Refurbishment

How Invisible Systems is Driving Sustainable Innovation

At Invisible Systems, sustainability isn't just a goal. It’s a core principle of how we operate. As an IoT company delivering environmental remote monitoring solutions, our technology helps customers reduce their environmental impact through actionable data. Now, we’re also reducing our own footprint by creating a circular economy through device refurbishment.

From Hardware Sales to a Sustainable SaaS Model

In 2022, we transitioned from a traditional hardware sales business to a subscription-based Software as a Service (SaaS) model. This change has enabled more businesses to access our monitoring solutions while giving us greater control over the lifecycle of our hardware.

Central to this model is the cost-effective management of physical devices. To scale responsibly, we developed a strategy focused on refurbishing and reusing existing hardware, specifically temperature sensors used in highly regulated environments such as pharmaceutical storage and food compliance.

The Pilot Programme: Circular Economy in Action

Launched in summer 2024, our temperature sensor refurbishment pilot delivered significant results:

• 71 percent of in-scope hardware sales were fulfilled using recycled devices

• 16 percent of total business is now driven by refurbished units

• 250 kilograms of plastic manufacturing avoided

• 1,500 kilowatt-hours of energy saved

• 750 kilograms of carbon emissions cut

• 10,000 litres of water conserved

• 250 kilograms of plastic waste diverted from landfill

These achievements mark the beginning of a broader shift in how we manage the lifecycle of our products.

Overcoming the Challenge

Shifting to SaaS meant owning our hardware and handling its full lifecycle, from deployment to end of life. Previously, temperature sensors were replaced after a year due to calibration standards, with the expired units sent to landfill or incineration.

Key challenges included:

• Inability to reuse devices due to data privacy risks

• No technical process for refurbishing and recalibrating returned units

• Lack of quality control standards for used hardware

Each year, more than 3,500 temperature sensors were deployed, generating over 640 kilograms of electronic waste, including hazardous printed circuit board materials. This translated to between 2.5 and 3.6 tonnes of carbon dioxide equivalent emissions if incinerated.

Our Solution: A Closed Loop System for Remote Monitoring Devices

As an ISO9001 and ISO14001 accredited organisation, we committed to embedding circular practices into our operations. Our refurbishment programme now allows us to:

• Wipe and reset device firmware to remove customer data

• Visually inspect and functionally test each device

• Replace batteries and degraded components as needed

• Recalibrate and recertify devices to UKAS standards

• Deploy refurbished units directly back into circulation

This structured process ensures that every refurbished device meets the same quality standards as new ones, at just 10 percent of the original bill of materials cost.

Reverse Logistics: Enabling the Circular Model

A vital element of our model is the reverse logistics system. Used devices are returned from customer sites to our lab, where they undergo disassembly, battery replacement, recalibration, and recertification. This enables us to turn previously single-use electronics into renewable assets, reducing both waste and the carbon footprint of manufacturing new devices.

Results and Measurable Impact

Since launching the refurbishment programme, 71 percent of in-scope devices sold have been recycled. This accounts for approximately 16 percent of our overall business activity.

From an environmental standpoint, the impact has been significant. Refurbishment has:

• Prevented the need to produce 250 kilograms of new plastic

• Saved 1,500 kilowatt-hours of energy

• Cut carbon emissions by 750 kilograms

• Conserved an estimated 10,000 litres of water

• Diverted 250 kilograms of plastic from landfill

Technically, our sensors are designed for durability, using simple printed circuit boards with no inherent hardware failure points. Refurbishment costs just 10 percent of the bill of materials of a new unit. These savings have allowed us to invest in longer-lasting components, such as improved enclosures, extending the useful life of each asset.

Operationally, holding a live inventory of refurbished sensors has improved lead times and reduced reliance on new manufacturing. Approximately 80 percent of our annual demand is now fulfilled using refurbished devices. This approach has lowered inventory costs and freed up working capital, supporting our growth as a scaling SME.

Encouraged by this success, we have begun extending our refurbishment model to other product lines. We recently developed a script to fully refurbish our cellular gateways, which play a key role in delivering IoT connectivity.

A Smarter, Greener Future

This programme demonstrates the potential of a sustainable technology strategy that benefits both business and the planet. Through innovation, refurbishment, and reverse logistics, we have aligned environmental responsibility with commercial scalability.

Our mission is to help organisations make data-driven decisions that improve operational efficiency and reduce environmental impact. With a circular economy now embedded into our operating model, we are better positioned to scale responsibly while maintaining our commitment to continuous improvement.

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