In the Val di Non valley in Trentino, Italy, 275 metres below ground, lies a network of abandoned mines running throughout the Dolomites mountains. For nearby fruit producer Melinda, the cool, dark conditions are, conveniently, just right for storing its fresh produce. Daniel Turri, project specialist at the company, says the Riomaggiore mines work in much the same way as a huge chiller. "Imagine a fridge like the one in your kitchen," saus Turri. "It's bigger - but the idea is just the same."
To keep its apples fresh, Melinda pumps air through oxygen filters into each storage cell, creating an environment that is 99 per cent nitrogen and one per cent oxygen. "The apples can still breathe, but very slowly," Turri explains. Within four days, the fruits' maturation has slowed to the point where they can be kept fresh for almost a year.
After the rock is chilled, it can stay at a consistent temperature for years. This ensures the machines pumping out cold air work less and the amount of water for cooling is reduced. When compared to a standard above-ground storage space, the savings are equal to ten Olympic swimming pools of water and ten hectares of land. And it uses only half the amount of energy.
The Trento-based firm has two storage cells, each of which can hold 10,000 tonnes of apples. The first was made in 2014 at a cost of €8.8 million (£7.4m). Turri says the plan is to create five such cells, connected by a central service corridor. Melinda only stores apples there, but the 15-kilometre network is suitable for other goods. "Producers could store cheese or wine," Turri adds. "There is a lot of space."
This article was originally published by WIRED UK
