Installations on residential rooftops surged in recent years but SunPower Australia business development manager Andrew Gilhooly reckons value in the commercial sector is often overlooked.

“A commercial rooftop, even before you put solar on, is an asset with tremendous potential in terms of revenue generation,” he says.

Faced with a project like that, installers who can’t explain the advantages and long-term value that premium technology will deliver may lose jobs to competitors who push low-cost solutions.

“There is an opportunity cost in not realising in absolute terms a much higher energy yield over the lifetime that a high-efficiency solar system provides.”

Here’s an example, using SunPower product, of course. A system which uses the company’s new 20.4%-efficient 435W panel, recently launched via Sol Distribution, will be about 25% larger in rated kilowatts than a system made up of 15%-efficient competitor product.

“Then you are really capturing the latent opportunity in the rooftop asset,” he says. “We can work with installers to provide array layout designs which can inform their own cost estimation.”

Higher efficiency systems also use less racking and cabling, which can offset the costs.

“There is a lot of low-cost solar out there,” he says, but SunPower justifies the associated price tag to its premium technology by offering added value to installers by including design and simulation expertise. “We want to alleviate that operational burden from the partners.”

Commercial jobs are seldom straight-forward, with shadows cast by HVAC, ducting, chillers and towering neighbours complicating things no end. SunPower can help with that, too, by offering 3D shade assessment for entire calendar years to deliver shade-loss as a percentage, which is then fed into an energy simulation, which takes into account local weather patterns, to spit out optimal kilowatt-hour yield.

“We can use that to optimise the system size — to maximise self-consumption and minimise export — which as we know offers the most compelling proposition to the customer.”

Lend a hand

The sad fact is there are some crummy installers around, who will push inferior product and disappear by the time any problems arise. Gilhooly can’t do much about that problem but he says SunPower’s offer of sharing its skills can be valuable “to our partners who are, shall we say, resource constrained”.

“It enables them to generate a solid design with an accurate energy simulation to support their proposal to the end user,” he says.

“We focus on the higher end of the installation market; we only work with partners who we feel are capable of selling value.”

Instead of selling an installation on a dollars-per-watt basis, Gilhooly emphasises the economic sense of conveying the full-lifetime value through cost of energy generated.

“We can do that, because the support for the energy simulations captures the yield advantage our technology offers,” he says, citing SunPower cell performance in high temperatures and low light conditions, and comparative statistics on degradation.

An 8% year-on-year advantage from better than benchmark performance in high temperature and low light, combined with lower degradation, means an equivalent-sized (in terms of area) higher-efficiency system will deliver between 40-50% more energy over the asset lifetime, he says.

The bendy cell

He demonstrates the SunPower Maxeon cell’s durability by passing your correspondent a “commoditised” cell and suggesting he give it a twist. Almost without any effort at all the blue square — the usual silicon wafer screen-printed with metallic contacts on one side and conductive paste on the reverse — shatters into fragments.

The SunPower Maxeon cell, a matte indigo square with no metallic strips on its face and a rigid copper substrate, bends … and bends … a little bit further … and finally cracks.

“There is much more deflection,” says Gilhooly, who started with the company as an application engineer. “You can discern the difference the copper substrate makes.”

The copper keeps the cell intact, he says. “Although there’s a hairline crack there, if you put that under an electroluminescence flash test, the only dark area will be the crack itself; either side of the crack will … still be generating energy.”

Rugged cells prove their worth in rugged terrain, he says. SunPower panels are used in the transportable SunSHIFT systems, along with ABB storage, where plants are trucked over bumpy terrain between outback sites well within a 25-year product warranty.

The company has had a presence in Australia since 2008 and is majority owned by French energy giant Total.