More than 90% of ski pistes in Italy use snowmaking. It is a technology that has revolutionised skiing, guaranteeing a season even when nature fails to cooperate. But how exactly does it work? What does it cost? And what is its environmental impact?
How artificial snow is produced
The physics
Artificial snow (more precisely “technical snow” or “man-made snow”) is produced by nebulising water under appropriate temperature and humidity conditions. Water droplets dispersed in cold air crystallise to form ice granules similar to natural snow.
The conditions required
To make snow you need:
- Temperature: below -2 degrees C (wet bulb temperature)
- Relative humidity: the lower the better. At 30% humidity, snow can be produced at -1 degree C
- Water: large quantities, typically drawn from purpose-built storage reservoirs
- Electricity: to power compressors and pumps
The two types of snow guns
High-pressure guns (lances): propel water upward (up to 10 m) where it crystallises in cold air. The most widespread, economical and quiet type.
Fan guns: use a large fan to project water droplets further. More expensive but more efficient at borderline temperatures.
Snowmaking in Italy: the numbers
| Data | Value |
|---|---|
| Pistes with snowmaking | Over 90% |
| Water needed for 1 km of piste | 1,000-3,000 cubic metres |
| Cost per hectare of snow | 2,000-5,000 EUR |
| Energy consumption per cubic metre of snow | 2-5 kWh |
| Snow depth produced per cycle | 20-30 cm |
Costs for resorts
Snowmaking is a major expense for ski stations:
- An average resort spends 500,000-2,000,000 EUR per year on snowmaking
- Investment in equipment (guns, pipelines, reservoirs) runs to millions of euros
- Costs account for 25-40% of total piste management expenses
Is artificial snow the same as natural snow?
No, but the difference is smaller than you might expect:
| Characteristic | Natural snow | Technical snow |
|---|---|---|
| Crystal structure | Star-shaped flakes | Spherical granules |
| Density | 50-100 kg/cubic metre | 350-500 kg/cubic metre |
| Feel on the piste | Soft, light | More compact, firm |
| Durability | Melts sooner | Lasts longer |
| Skiability | Excellent | Good to very good |
Technical snow, being denser, withstands skier traffic and sun exposure better. This is why pistes prepared with man-made snow maintain uniform conditions for longer.
Environmental impact
Snowmaking has a significant environmental footprint:
Water consumption
An average resort consumes 100,000-300,000 cubic metres of water per season. To reduce the impact, many stations have built storage reservoirs that collect rainwater and snowmelt, returning it to the natural cycle.
Energy consumption
Energy use is considerable but improving:
- The latest snow guns consume 30-40% less than those built 10 years ago
- Some stations use renewable energy (hydro, photovoltaic)
- Automation systems optimise production based on temperature and humidity
Additives and chemicals
In Italy, technical snow is made exclusively with water and air. No chemical additives are used (unlike some stations in North America where nucleating agents are employed).
The future of snowmaking
With climate change reducing natural snowfall at lower altitudes, snowmaking becomes ever more critical. Current innovations include:
- IoT systems: real-time temperature and humidity sensors to optimise production
- Snowfarming: storing snow from winter through summer under insulating covers
- Multi-function reservoirs: basins serving both snowmaking and summer irrigation
- Next-generation guns: more efficient, quieter and operable at higher temperatures
For a deeper look at the climate challenge facing the Alps, read our article on climate change and the future of skiing.