Solar carports represent an essential component of the energy transition, by making sealed surfaces available for photovoltaics, creating a foundation for charging infrastructure, and supporting companies and municipalities in decentralised power supply. Despite these advantages, numerous projects already come under economic pressure during the conceptual phase. According to the engineering company PILLAR, the actual cost drivers are often not the solar modules themselves, but factors such as ground conditions, foundations, structural engineering or approval procedures, the consideration of which is delayed in the planning process.
Vasyl Betsa, Managing Director and founder of PILLAR, a company that has been realising solar carport projects for over ten years, emphasises that the economic viability of projects less often fails due to photovoltaic technology, but rather due to insufficiently clarified framework conditions. Even minor modifications can cause four-figure additional costs. For larger commercial or municipal installations, delays and adjustments to foundations quickly accumulate into six-figure sums. When developing multiple sites in parallel, the additional costs can even reach millions. According to PILLAR, this cost risk usually materialises not during the construction phase, but at an earlier planning stage, when essential fundamentals are incorporated into considerations too late.
Ground Conditions and Structural Engineering: Decisive Factors for the Project Budget
A significant uncertainty in the planning of solar carports lies in unknown subsoil conditions. Early investigation of ground conditions and groundwater levels is therefore of high relevance. Soil parameters and groundwater levels are usually determined by means of a geotechnical report. However, if these investigations are commissioned or evaluated too late, crucial findings can no longer be incorporated into the planning in a timely manner. Unexpected obstacles such as existing pipes, cable routes, old foundations or other underground installations often only come to light during construction work. This leads to necessary adjustments of foundation positions or interruptions to the construction process, which in turn result in delays and additional costs.
The importance of structural engineering goes beyond a mere formal verification. It is based on specific assumptions regarding ground conditions, wind, snow and traffic loads. If these assumptions do not match the actual site conditions, often not only the foundations are affected. An adjustment of the support structure may become necessary if it was undersized based on the original assumptions and the required structural stability can no longer be guaranteed. The significant additional costs therefore frequently do not result from the solar modules, but from the foundations and the structural design.
Approval Procedures and Infrastructure Integration
Approval processes regularly develop into a critical time factor. Glare assessments, fire protection requirements, structural integrity reviews or environmental regulations are often only thoroughly examined when the technical planning is already well advanced. If essential requirements only become apparent during the course of the approval procedure, this leads to renewed review cycles or plan changes, as Vasyl Betsa explains. Adjustments to parking space layouts, fire brigade access routes or structural details then have an immediate impact on schedules and costs.
The integration of grid connection and charging infrastructure is often incorporated too late into the planning process, although the importance of energy infrastructure in car park areas is steadily growing due to the expansion of electromobility. The availability of sufficient grid capacity at the site should be checked at an early project stage. Grid connection requests and grid compatibility studies by the grid operator often take several weeks or months, a time expenditure that is regularly underestimated in project planning. Late findings can necessitate additional civil engineering work or subsequent adjustments. A solar carport is now part of an integrated energy infrastructure, meaning that photovoltaics and grid connection should be planned together early in project development.
- —Late consideration of ground and groundwater conditions.
- —Insufficient analysis of structural requirements in relation to actual site conditions.
- —Delayed or incomplete processing of approval procedures.
- —Inadequate or late integration of grid connection and charging infrastructure.
In conclusion, practical project experience shows that many solar carport projects do not fail due to solar technology, but due to avoidable planning errors. The economic viability of a project is often decided before the first foundation is laid. This requires comprehensive and forward-looking planning that integrates all relevant site conditions and regulatory requirements at an early stage.
