Sustainable cold storage in the lab: ready to reduce costs and environmental impact?
Cold storage quietly runs up one of the biggest energy bills in the lab.
Cold storage is one of the main reasons labs are so energy-intensive in the first place; the sheer number of fridges and freezers running continuously takes a real toll. Ultra-low temperature freezers in particular are worth a closer look, because a single change to how they're run can make a disproportionate difference.
Temperature tuning: chill up, don't just chill down
One freezer at –80°C can consume as much energy as an entire average household. Raising it to –70°C instead can save up to 40% of that energy, and there's now a great deal of scientific evidence, from many labs across academia and industry that have already made the switch, that most samples are perfectly fine at the higher temperature. Warmer set points also extend equipment lifetime and give freezers more stable temperatures, which in practice means fewer alarms and far fewer late-night trips to the lab to check whether a freezer has failed and samples need evacuating. It's a reasonable thing to feel cautious about, but the evidence base is now substantial, and running a test on non-critical samples first is a sensible way to build confidence in your own lab.
Store at the right temperature, not the coldest one
The colder a sample is stored, the more energy goes into keeping it that way, which is why one of the better cold storage habits is choosing the right temperature for the job rather than defaulting to the lowest one available. It costs less energy to open a fridge than a freezer, and both financially and environmentally, it's a better trade to add another –20°C freezer than another ULT unit if storage capacity is genuinely needed.
Beyond the set point
Defrost freezers regularly, since ice build-up forces the compressor to work harder. Discard old samples so freezer space isn't sitting occupied by material nobody actually needs anymore, and use sample storage boxes to keep the space that remains organised and efficiently packed. Retiring genuinely old fridges and freezers, or replacing them with more energy-efficient units when the time comes, adds up as well.
The payoff shows up fast
Cold storage optimisation is one of the rare sustainability actions that costs nothing upfront and shows results within the same billing cycle. It needs no new equipment and no change to how researchers actually work day to day, which makes it about as close to a free win as lab sustainability gets.
