15 March – Case study: Saving energy is not normally linked to the start of the AFL season but that’s what the new redeveloped Gold Coast stadium – home of the appropriately named Gold Coast Suns – is all about.

The owner, Stadium Queensland, worked with key consultants: Norman Disney & Young, engineers; ARUP, structural engineers; architects, Populous and builder, Watpac to adapt a fully integrated solar solution which will be promoted as part of the Gold Coast’s 2018 Commonwealth Games bid. Funding was provided by the Queensland Government, Federal Government, Gold Coast City Council, and the Australian Football League

The work incorporated a solar photovoltaic roof designed to generate 20 per cent of the stadium’s forecast annual energy consumption, in line with the Federal Government target.

Energy generation
In what is claimed to be  a Queensland first, the solar roof is expected to generate about  275 megawatt hours of electricity a year  and will be connected to the Energex electricity network.  This is the equivalent of powering more than 250 homes in Queensland, according to NDY’s . The PV panelling, which is five metres wide, will be installed over 450 metres of roofing.

Other energy efficiency measures already incorporated into the design of the stadium include high efficiency airconditioning, energy efficient lighting, and water harvesting. Materials from the previous stadium, which was demolished, have been recycled.

According to NDY, the stadium’s solar panelling uses Scheuten Optisol sandwich glass panels, providing high levels of visibility from below. The cell spacing has been designed to ensure sufficient light is passed to prevent a solid shadow line on the field –a key consideration for the design team.

Scheuten was able to demonstrate a proven track record and undertake comprehensive testing demanded from the design team while delivering against the very stringent installation program, NDY said.

Other distinguishing features of the project
Integration into the existing roof design was challenging. The initial option was to mount the panels almost flat with a uniform leading edge, with the panels sloping down slightly towards the rear of the stands to capture the stormwater.

The final solution involved 39 individual bays, each comprising 8, 14 or 18 solar panels mounts over a curved bay.  Viewed from the front the bays present as a series of curved elements best understood by viewing the pictures.  Each panel slopes to the side and backwards to allow capture of stormwater.

Because of the horseshoe roof, each bay presents at a different orientation to the sun, while each of the panels that make up the bay present at a range of inclinations to the sun.

The complex geometry required to incorporate the solar panels into the roof’s architectural design made the assessment of power generation time-consuming.  However it was shown that the  electrical generation would not be adversely impacted and  the decision to proceed with the curved solar roof was justified.

Detailed investigation showed that the potential generation of the curved solar roof is 1–2 per cent less than the almost-flat roof design. But the majority of panels have improved angles for self-cleaning, which makes the curved roof marginally better in terms of overall generation efficiency.

Technical details
Distributed installation comprising 16 Sunny tripower inverters from solar technology company, SMA, were grouped geographically.  Each inverter feeds back into the local (stadium) low voltage reticulation system at one of six switchboards.
Utility class metering is provided at each of the six low voltage supply points to allow calculation of renewable energy generated.  A single high voltage net export meter is located at the connection between the stadium distribution system and the utility grid.

Communication with the SMA inverters is from a central monitoring and control computer and a system of Sunny web box interface controllers.  Proprietary software has been used to facilitate maintenance and monitoring of the solar system from onsite or a remote location.

Future outlook
Concept plans have been drawn up for approximately one megawatt of peak capacity on the site, with implementation being subject to future funding.

NDY’s Senior Associate and ESD manager, Connan Brown, said: “This is a very exciting project for Norman Disney and Young and also for me personally, but most importantly a very good result for the stadium stake holders. Full credit to the architect and design team in achieving a fully integrated solar solution within a unique roof form – an outstanding aesthetic result..”

The capacity of the system is 220kw, producing  “approximately 275 mwh per year” or “approximately 275,000kwh per year” according to Mr Brown. “The difference in capacity is a physical quality like the capacity or power of your car’s engine. The generation is a function of sunshine, cleaning and what direction the panels are pointing and based on one year of weather – like the petrol consumption of a car”

Details

Owner: Stadiums Queensland
Overall project cost: $144.2 million (whole of stadium figure)
Funding arrangements: Jointly-funded by the Queensland Government, Federal Government, Gold Coast City Council, and the Australian Football League.
Architect: Populous
Managing contractor: Watpac
Contractor: Stowe Electrical
Fuel source: Solar
Prime mover: Scheuten Optisol, SMA Sunny Tripower

Employees:

Steelwork: approximately 12
Glasswork: approximately 6-8
Electrical: approximately 4

Workers in operation:

Monitoring – 1-2 people intermittent
Cleaning – 4 man team intermittent

Key engineering firms – Solar Services
Connan Brown
Norman Disney & Young

Architect
Chris Patterson
Populous

Key engineering firm – Structural
Josh Neil, ARUP

Construction – main contractor
Gary Gisik, Watpac

Construction – provider / installation sub-contractor
Les McMahon, Stowe Australia

Compiled with the assistance of Norman Disney & Young