One Central Park – Heliostat and Reflector System

The style of the products (both Heliostat and Reflector) has been specifically developed to separate the technology from its industrial and agricultural heritage and introduce it into the new environment with an urban aesthetic. The angular form is the result of a desire to minimise the visual profile of the product, enabling the technology to blend more efficiently into the architectural surround. The overall design remained heavily informed by manufacturing limitations and opportunities and structural engineering factors such as wind tunnel testing. The final aesthetic is intended to evoke a technological response and communicate that the mechanical nature of the system is evolved.

The system delivers natural light into the retail precinct and surrounding site locations as the design concept intended. The architect desired to achieve an effect of 'dappled light' such as one would experience under a tree canopy, rather than harsh edged reflections or a direct sunbeam. The dappled effect is amplified in the retail area by running water on the atrium glass roof, resulting in a dynamic experience. The controlled delivery of natural light improves the living experience for residents and visitors to the site. In the park or by the pool, people can sit in a single reflection for long periods of time in an area that would otherwise be shaded by buildings, or be subject to transient sunshine.

The lighting strategy was simulated using ray-tracing software which enabled a predictable end result to be envisioned prior to build. The simulations and safety features minimise the chance of stray reflections and solar concentration. System failures are monitored onsite and offsite, and the heliostats automatically respond to protect residents, shutting down the offending mirror in the event of error. The heliostats regularly self-calibrate to ensure the highest accuracy in their sun-tracking process. The products comply with necessary building regulations and structural engineering codes. The system operations are integrated into the building services providing for low input operation and minimal maintenance.

The system is a significant step towards sustainable living by producing light and heat using natural resources, offsetting the need for artificial environments. There are also benefits in landscaping applications where necessary sunlight is directed onto plants to promote growth. Sustainability can be measured with respect to how this product can add value to urban developments, through provision of solar access with low energy consumption. The product can be disassembled for maintenance purposes. Most materials are recyclable however due to the application they are not expected to be. The unique mirror material is available due to significant investments being made in concentrated solar thermal markets.

Material selections were arrived at with a balanced consideration of mechanical and structural engineering performance, and architectural design intent. The manufacturing methodology adapted aeronautical assembly techniques achieving accuracy in assembly, quality in finish, and the durability necessary to survive in an exposed site location. The products are designed with a 25 year design life in mind and combine materials from a variety of industries. Maintenance programs were developed specifically for the unique combination of materials and their deployment in an unusual location.

The Heliostats system is an innovative application of public artwork funding into a functional technology that delivers tangible benefits to residents. As one of six key technologies in the building and a focal point for the site, the Heliostat system assisted the developers in receiving industry awards including 'Best Building in the World 2014′. A full list of the awards won by the building can be found at http://www.centralparksydney.com/explore/awards-won. Future applications for the product system offer significant return on investment opportunities for developers by allowing them to overcome solar access issues which would have otherwise limited development heights. New projects are underway.

The installation is a world-first with respect to the sheer size and application. Whilst small heliostats have been used in architecture before they have never been applied on a scale such as that seen at One Central Park. Heliostats have not been used specifically to address solar access concerns of councils, representing a significant opportunity for future application. The design utilises materials specifically developed for the concentrated solar thermal industry (aluminium mirror surface on composite panel) in an urban environment achieving a safe and lightweight product. The material durability facilitated the installation, something which would not have been attempted with traditional glass mirror.