Bristol Airport -1.4MW

At Bristol Airport, an unconventional foundation called for a different way of thinking.

HTR Solar provided the design and manufacture of the mounting system for this 1.48MW ground-mounted solar project, using our S4.1 4-in-Landscape system with a 100% ballasted foundation solution.

Working within a tight project budget, reclaimed concrete railway sleepers were selected as the ballast. For our engineering team, the challenge was to turn these existing materials into a practical structural solution developing how the mounting system would connect securely to the sleepers and how they could be arranged to provide the required stability.

The final configuration created an almost Jenga-like arrangement beneath the arrays, with layers of concrete sleepers carefully positioned to provide ballast while supporting an efficient and buildable mounting system. The approach also avoided the need for conventional deep-driven foundations.

For HTR Solar, Bristol Airport demonstrates that good engineering is not always about starting with a standard detail. It is about understanding the materials, constraints and economics of a site and developing a solution that brings them together.

Here, reclaimed infrastructure became the foundation for renewable infrastructure.

100% Ballasted Foundation-The site required a fully ballasted solution, avoiding conventional driven piles and demanding careful consideration of stability and load distribution.

Reclaimed Railway Sleepers-The client sourced reclaimed concrete railway sleepers for the ballast, requiring HTR Solar to engineer a practical and secure method of connecting our S4.1 structure directly to them.

The “Jenga” Challenge-The sleepers had to be stacked in carefully arranged layers to achieve the required ballast — creating a distinctive Jenga-like foundation while maintaining structural performance and constructability.

Engineering Within Budget-With a tight project budget, the challenge was to make the available materials work efficiently,  balancing structural performance, installation practicality and cost without over-engineering the solution.