Flinders Medical Centre, Adelaide, SA … the long load

CATEGORY: Over 240kW

Daniel Westover and Nathaniel Elliot, Keystones Solar Group

If a business wants to cut energy costs and do its bit in reducing emissions from the generation of grid energy, then rooftop solar is a simple solution. Getting onto the roof, however, isn’t always so easy. “There were a few challenges on this site,” Keystones Solar Group director and project manager Daniel Westover tells EcoGeneration. “We were unable to use a crane to lift anything onto the roof due to the landscape and limited access to the building.”

Luckily the Keystone crew had a panel lifter they could use to hoist the 2,552 Trina TallMax 450W panels, 1,278 SolarEdge P950 optimizers, 11 SolarEdge inverters and Sunlock racking onto the roof via the southern staff entrance on the fourth floor of the car park.

“We were only allowed a daily window between 10am and 2pm to set-up, utilize and pack down our lifter,” Westover says. “At the same time we were unable to overload the roof with point loading simply because we were unpacking panel pallets to lift them. This meant that we were constantly moving stock, daily as the build evolved, across a roof spanning up to 190 metres.”

Back and forth

To make the work bearable (and safe), Keystones installed north-south walkways and built two custom trolleys to truck the gear about. The roof is also an unusual shape, Westover says, which made it a challenge to finalise the layout prior to winning the project at tender.

“The panel layout constantly changed, especially after the walkway installers finished their work, which restricted us further,” he says. “Up until the last panel was laid we were unsure of the exact finished panel number.”

The 1.14MW system is the largest Keystones has delivered and it goes to show what can happen when you back yourself. “Right from the tender application process we recognized the challenges and specifically the areas where our business was lacking,” Westover says. “We were extremely confident in our abilities to physically deliver a high-quality install to any size. However, we knew that if we were going to properly manage expectations we needed to improve our internal documentation and management system processes.”

Two goals were pursued at once: invest in business operations and put in the best tender possible. “This needed to be done during the tender process, to allow us to properly represent ourselves as a viable consideration for the project.” The effort paid off when news came through they’d won the job.

The Flinders Medical Centre site consists of thirteen 1MW transformers. The solar infrastructure is fed directly into its own transformer and then shared within the site via its private HV network. There is zero export to the local network and Westover estimates the PV solution is supplying about 10% of maximum demand during peak times.