The hidden environmental cost of cold storage in laboratories

Research laboratories are among the most energy-intensive spaces on university campuses, and one of the largest contributors to this demand is often hidden in plain sight: cold storage. 

Laboratories are seeing increasing demand for ultra-low-temperature (ULT) freezers, standard freezers, refrigerators and liquid nitrogen storage systems to preserve valuable research samples and reagents. 

These systems are essential to research, but carry a significant environmental and financial cost. 

For instance, a single ULT freezer can consume as much energy as two average UK households in a year. At my university, more than 500 ULT freezers support research and biobanking activities, alongside thousands of additional cold storage units distributed across laboratories. 

And the challenge extends beyond electricity consumption. Many cold storage units remain in service for decades, becoming increasingly inefficient over time. The heat generated by these systems places additional pressure on laboratory ventilation and cooling infrastructure, further increasing energy demand. 

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At the same time, academic institutions often face growing pressure on space, with storage units occupying valuable research areas. Samples that are no longer actively used, involving materials left behind by former researchers and students, can continue to occupy valuable freezer space for years. 

Build institutional momentum 

At my university, our sustainable research team works to improve laboratory sustainability through accreditation programmes, research projects and targeted operational improvements. Amid sector-wide sustainability commitments and increasing expectations from funders and stakeholders, cold storage has emerged as an opportunity to reduce emissions while improving research efficiency and resilience. 

Our experience has shown that technical solutions alone are not enough. To improve cold storage in research environments, we need to address both infrastructure and researcher behaviour. A combination of institutional support, infrastructure investment and engagement with the research community is the only way towards a lasting improvement.

We found out that rolling an institution-wide cold storage campaign with friendly audits was key to strengthening engagement and sharpening the understanding of key barriers to create momentum. Here’s how we did it.

Cold storage campaign: combining behavioural and infrastructure change 

As a first step, to support laboratories in modernising their equipment, we introduced a freezer exchange scheme that enables researchers to replace two older, inefficient ULT freezers with a single modern, full-rack, energy-efficient unit. The programme reduces electricity consumption and frees up valuable laboratory space at the same time. 

To date, the scheme has replaced 144 legacy ULT freezers, generating estimated electricity savings of approximately 742 MWh, while releasing 72 square metres of laboratory space. 

But simply replacing equipment does not guarantee success. For these programmes to be effective, users need to change their day-to-day activities. This includes accurate inventories of cold storage assets, cleaning out samples, ongoing monitoring of performance and procurement standards that prioritise energy-efficient equipment. 

Laboratory users are an imperative part of the whole process – they need to engage with the initiatives to ensure that new systems and space are used effectively.

Use friendly rivalry to chill out lab culture 

By turning cold storage into a competitive sport, our sustainable research team has transformed how scientists manage their samples. Since launching an internal version of MyGreenLab’s International Freezer Challenge in 2023, the university has successfully signed up roughly half of its research departments. 

The result? A massive energy drop of 345 MWh per year, equivalent to powering 130 average UK homes. 

The initiative proves that high-impact sustainability and cutting-edge science go hand in hand. Labs secure bragging rights and awards by mastering the basics of cold-storage hygiene: 

• Purging the past: clearing out expired or redundant samples
• Smart stacking: upgrading tracking and racking systems
• Routine care: defrosting units and performing regular maintenance
• Thermostat tweaks: optimising storage temperatures

Data alone did not drive this behavioural shift, but also creative communication. We used regular campaign updates, a punchy promotional film and peer-to-peer networking to rally the technical community. 

By making freezer maintenance a shared institutional goal, good practice is fast becoming the default setting for laboratory culture. 

Support decision-making with data

As a last important step, the campaign targeted case studies to help us better understand cold storage performance and identify opportunities for improvement. Comprehensive cold storage audits were conducted, and a full inventory of cold storage equipment was combined with detailed energy monitoring. 

Legacy ULT freezers revealed an average electricity consumption of 18.4 kWh per day per unit, higher than initially expected and 2.5 times more than a new unit. In some cases, freezers more than 20 years old were found to consume shocking numbers of over 30 kWh per day. 

These findings provided valuable evidence that enabled us to prioritise replacement of the most energy-intensive equipment, improving sample security while reducing energy costs and emissions. 

Researchers within the biobanking area at St Thomas’ Hospital faced a different challenge, struggling with constraints on storage space. By working collaboratively with laboratory teams, the technical managers implemented high-density storage solutions by downsizing tube formats for sample storage. They almost doubled the storage capacity, allowing expansion of the biobanking without requiring additional freezers. 

Lessons for other institutions

Our experience suggests that improving the sustainability of cold storage does not require a single transformative intervention. Instead, success comes from combining behavioural change, robust data and targeted infrastructure investment. 

For institutions looking to begin or expand similar initiatives, several actions can have an immediate impact: 

• Develop and maintain an accurate inventory of cold storage equipment
• Engage researchers through programmes such as the Freezer Challenge
• Link sustainability initiatives to improvements that researchers value
• Monitor energy performance to identify priority areas for intervention
• Establish procurement standards for energy-efficient equipment
• Explore opportunities for storage consolidation and high-density solutions
• Secure both senior leadership support and grassroots engagement

Our journey proves that sustainability and research resilience are a win-win. Also, by combining grassroots community engagement with evidence-based decision-making, institutions can strengthen the efficiency and security of their research operations. 

Through campaign updates, promotional films and peer-to-peer engagement, our team is starting to normalise good practice, proving that the road to net zero can actively benefit campus innovation and more responsible research. 

Marcelo Salierno leads the sustainable research team at King’s College London.

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