Critical infrastructure monitoring in the Swiss Alps

At 1'857 metres above sea level in the Swiss Alps sits the Limmernsee dam: an arch dam 146 metres high, 370 metres long, holding back 92 million cubic metres of water. It's part of one of Switzerland's largest power plants. This kind of critical infrastructure has to be monitored properly as it ages.

Axpo, Switzerland's largest producer of renewable energy, now tracks the dam's condition with wireless sensors that feed data straight into akenza. The full sensor installation went live in a single working day. Connecting those sensors to the cloud took minutes.

Here's the full story.

Concrete moves

Concrete in a dam expands and contracts as the seasons change. Over decades, that movement shapes how the structure ages. Axpo runs an investigation project to understand this process precisely, using finite-element simulations of the concrete's behavior over time.

To support the simulation, Axpo needed additional measurements from the structure. What the weather was doing to the dam: global solar radiation, wind speed and direction, air temperature, surface temperatures. The things that drive the concrete's temperature.

Taking these measurements by hand isn't practical here. Wired sensors have their limits on a structure like this. Low-power wireless sensors were the obvious choice.

Where wireless earns its place

Axpo installed battery-powered sensors at specific points across the dam. Each one measures at regular intervals and transmits over LoRaWAN, and a single LoRaWAN gateway covers the whole area. No wiring required. And because they draw so little power, the sensors run for years on their batteries with little maintenance.

That turns periodic snapshots into a continuous record, laid out on an akenza dashboard the team can read at a glance. Axpo now sees what the dam is experiencing hour by hour. 

The readings flow into akenza, are decoded, normalized and enriched before feeding Axpo's finite-element models of how the concrete ages. Better input means more precise simulations of a structure that has to stand for generations.

Critical infrastructure, made simple

Dam monitoring is just one of Axpo's projects on akenza. Other hydrology monitoring projects are in progress across the Alps. They run on different connectivity technologies depending on the specifics of each location, and all feed data to wherever Axpo needs it.

The dam project took a day to install and has delivered constant data ever since. Monitoring critical infrastructure, it turns out, can be simple. For anyone with a hard-to-reach structure to watch, the Limmern pumped storage power plant shows what wireless monitoring on akenza can do.