A comprehensive digital twin serves as the backbone of a pioneering project to install 5,700 massive solar panel tables on a steep, snowy mountainside, catching rays across 330,000m2 of Alpine terrain. It is part of Switzerland’s ambitious Solar Express renewable energy initiative. The digital-first strategy is key in overcoming the project’s many unique challenges, including steep terrain, heavy snow, severe winds, a fragile ecosystem and a short construction window.

With electricity demand forecast to rise significantly, and spurred by the accelerating effects of global warming, there is a new sense of urgency to develop alternate sources of energy in Switzerland. The nation is forging a new path to eliminate the use of nuclear power, reduce its reliance on imported fossil fuels and achieve net zero transmissions by 2050. The country’s Solar Express programme has been initiated to accelerate the expansion of renewable energy and increase energy efficiency to achieve these ambitious goals. Based on the massive effort underway to construct new production facilities, the Swiss Electricity Law expects photovoltaic (PV) power generation to increase fivefold from current levels by 2035, and nearly tenfold to 45TWh by 2050.

Solar Express is focused on boosting domestic winter energy production to compensate for seasonal and weather-related variations and help close the winter electricity gap. Proposed projects across Switzerland are at varying stages of approval and development. As part of this ambitious expansion of the renewable energy capacity, the high Alpine solar park near the village of Sedrun in canton Graubünden is under great pressure to show results. Upon completion in 2028, the installation of 5,700 solar panels will generate power for 6,500 homes. Around half of the electricity generated by the new $100 million facility will be in winter when demand is high.

When Marco Graf and Fadri Jecklin from InfraDigital were approached by a solar planning and installation company with a unique proposal to support this project, the two geomatics specialists were intrigued. The project represents more than just professional achievement – it’s a contribution to a sustainable future. “I think solar energy and all renewables are very important,” Graf reflects. “It’s especially interesting that we started on a green field. There were no existing systems. We had the opportunity to develop all-digital processes from the beginning.” To advance the project, InfraDigital joined forces with renewable energy firm Reech and engineering firm X Statik to form Zendra AG, specializing in Alpine photovoltaic projects.

Visual rendering of the SedrunSolar project area, which includes 5,700 solar tables. (Image courtesy: Sedrun Solar AG)

An Alpine challenge

The team quickly discovered that this wasn’t just another solar installation. The Solar Express presented a perfect storm of challenges that would test the team’s technical expertise and innovative mindset. At 2,200m elevation, those challenges include steep terrain, heavy snow, severe winds, a fragile ecosystem and a short construction window. “You can only work for a few months each year in these elevations,” notes Jecklin. “Construction starts in May, but by October it can be snowing again.”

The harsh Alpine environment doesn’t just compress the timeline, it dramatically complicates the installation itself. Each of the 5,700 solar tables measures 7.5m by 2.5m and must stand at least three metres above ground to account for heavy snowfall. The rocky terrain makes securing these tables extra difficult, with each location requiring custom leg lengths to adapt to the mountain’s contours. Careful placement can minimize environmental impact while maximizing energy production. Then there are logistical nightmares: sensitive conservation areas, expensive helicopter transportation for equipment, and the engineering challenge of designing structures that can withstand extreme Alpine conditions. These include high winds and ‘creeping snow’ – a powerful force as snowpack slowly moves downhill, putting immense pressure on the table legs.

Perhaps most critically, there was the challenge of community support. “Without public acceptance this project would fail, and future projects will be in jeopardy without success right now,” Graf acknowledges. “We needed to show people how we addressed their concerns and minimized disruptions on the mountain.” According to Graf, this would have been extremely hard to do without digital technology: “Inputs to create the optimal design had to be comprehensive and very accurate, and many different groups had to review and understand the details. The time and cost to realize such a large-scale project would have been prohibitive without a central information database.”

On-site visit with SiteVision, focusing on environmental topics and conversations with alpine farmers and local residents. (Image courtesy: ZENDRA AG)

Bringing the mountains to life

Rather than approaching these challenges with conventional methods, the team embraced a digital-first strategy based on a comprehensive digital twin of the entire project. All data compiled from various sources – including publicly available aerial imagery and aerial laser scanning (ALS) data specifically collected for the project – was stored in Trimble Connect with the design data. The combined dataset served as the basis for InfraDigital’s development of the parametric distribution of the solar tables across the terrain. Local Trimble distributor ALLNAV was instrumental in creating a custom Trimble Access application to simplify the stakeout process for the anchors of the solar panels.

The digital foundation became the primary source of information for stakeholder communication and issue management. “It provided a user-friendly tool for us to manage and share data,” explains Graf. “We included all the stakeholders – from the electricity company to specialists in the planning process, to environmental protection groups. They all had access to the same model, so they had a shared understanding of the project.”

The team’s breakthrough moment came when they made use of augmented reality technology to help overcome one of the project’s biggest hurdles. Using Trimble SiteVision, the model was loaded to an iPad directly from the cloud and overlaid on the actual terrain to allow landowners to visualize the installation from any location in real time. “If you are open and transparent with the community members, they are more willing to allow such a project to happen,” Jecklin adds. The local population voted to support the project in August 2023.

Screenshot of another on-site visit. (Image courtesy: ZENDRA AG)

Scaling up

With approvals secured and planning complete, the team moved to the construction phase. First, they built three test tables in the mountains, followed by the construction of 20 more tables after the Graubünden cantonal government issued the building permit in May 2024. Throughout the summer of 2025, the project will scale up dramatically, with the team preparing to install over 1,000 tables – nearly 20% of the total planned installation.

The digital model continues to serve as the project’s backbone, containing detailed information about every table, including the exact specifications needed for industrial-scale production. The part list generated in Trimble Connect is shared with the steel construction company so they receive the correct measurements. “Each table is different, and you have to produce them separately, correctly,” explains Graf. “We have to be sure when the helicopter delivers the table it will fit, so we don’t waste time.”

Construction company CrestaGeo and the team implemented innovative solutions like a custom drilling machine equipped with Trimble Groundworks software, eliminating the need to manually stakeout each drilling hole. The system ensures that installation is efficient and customized for each point, saving material and time, and reducing environmental impact.

Prototype of a drilling system designed specifically for alpine solar installations, named “Muntaniala” (Rhaeto-Romanic for “marmot”). (Image courtesy: CrestaGeo AG)

A sustainable legacy

In anticipation of the project scaling up in the summer, with three custom drilling machines operating simultaneously, the team are already preparing to tackle new challenges. Among other things, they are reworking their stakeout application and implementing systems to gather field information, including construction management data with location information and pictures.

The all-digital connected workflow supports every aspect of the project, from planning and design to surveying, construction and drilling, so the digital model will continue serving long after construction is complete. Attributes and lists of parts for every table are available during construction and to support future maintenance and disassembly. “Data will be very important for the maintenance phase,” Graf confirms. “We’re collecting all the serial numbers of the installed parts. If there’s a warranty issue, we’ll know where each panel is located.” Monitoring systems will allow for predictive maintenance and real-time optimization of energy production based on weather forecasts and grid demands.

As Switzerland and the world watch this pioneering project unfold, the real success may be in proving what’s possible when cutting-edge digital tools meet renewable energy ambitions, even in the most challenging environments on Earth.

Total station used to precisely align the drilling pallet to the drilling vector. (Image courtesy: Donatsch + Partner AG)