Solar tracking market leader NEXTracker today announced an energy storage add-on for its signature product.

Solar trackers have seen tremendous growth in the last few years as costs come down. That growth stayed strong this year in spite of slowdowns and turmoil in other sectors of the solar industry. Trackers now account for 70 percent of U.S. ground-mount projects.

As the tracker industry matures, companies are feeling more pressure to differentiate themselves from rivals. The competition is fiercest between NEXTracker and Array Technologies, which respectively controlled 24 percent and 20 percent of the global market in 2015, respectively, according to GTM Research.

NEXTracker upped the ante with its new NX Fusion Plus. It leverages "best-in-class solar tracker, battery, inverter and software technologies," the company said, to extend the usefulness of a tracking solar plant. 

Other tracker companies bundle trackers with inverters and balance-of-system components, and developers could already deploy storage alongside a solar tracker project. But this formulation is a new development for the industry.

"There’s not another tracker vendor that offers that at the moment," said Scott Moskowitz, the senior analyst at GTM Research who follows solar trackers.

Choices, choices

The current plans are to offer two main storage choices, which cater to different sets of customer needs, said NEXTracker CTO Alex Au. One option is the containerized lithium-ion package made by parent company Flex; the other is to integrate long-duration flow batteries from a yet-to-be-announced partner directly into the rows of trackers.

"We’re not just white-labeling something; we’re creating an improved system together and leveraging our existing infrastructure," Au said.

The DC-coupled flow battery system would be able to absorb solar generation while minimizing the efficiency losses of extra power conversion. It would also address the problem of "clipping," in which generation isn't sent out because a system's inverters can't handle the capacity at a given moment. The storage can hold onto that extra power and push it out at a later time.

And, of course, storage can do plenty of other things too. In describing the product, Au endeavored to find a middle path between two extremes: lack of choice and too many choices.

"A lot of times with storage, when you don’t have more than one tool for the customer to use, you force a solution and it’s not as genuine," he said. 

On the other hand, if the storage provider steps back and offers a blank slate, the customer doesn't benefit from the expertise of the company. And if the company builds a custom design for every customer, it forfeits the cost savings that come from a battery design that's highly integrated into the tracking system.

Au sees his company's storage packages as "a toolbox, and there are certain tools needed for certain tasks." NEXTracker will suggest the best of the available tools for each customer's use cases.

Huge utility-scale solar plants may gravitate toward the lithium-ion option to add some grid services abilities to their portfolio. But NEXTracker will also pursue smaller customers, like farms that struggle with hefty demand charges, or big-box stores that want more control over their energy usage.

How big can it be?

The lithium-ion product is ready now, Au said. The flow option will leave the factory in Q2 2017. Most of the leads so far are in California, as is to be expected with storage. But Au said his team is examining other markets as well.

That points to a constraint inherent to adding storage to the platform: The storage markets themselves are still small and geographically limited. That means the storage-plus-tracker probably won't be a big driver of NEXTracker's bottom line any time soon.

"The real driver for tracker vendors going forward will be the growth of tracking in markets outside of the U.S.," Moskowitz said. "It’s going to be places where utility solar is still developing, like China, India, the Middle East and Latin America."

"I don’t think a storage application is going to fundamentally change that," he continued. "But it should allow NEXTracker to differentiate itself from competitors who don’t have that capability, and it lets them appeal to customers who need the specialized production profile that storage provides."

In the near term, then, the NX Fusion Plus can appeal to specific customers with specifics needs.

Longer-term, Au envisions NEXTracker selling fully integrated clean energy systems that can serve their customers as well as the grid. The company has an ongoing project that aims to "decapitate the duck" by smoothing out the evening peak of the famous "duck curve" with solar production from earlier in the day. This new offering contributes to that, in a streamlined and user-friendly way.

The first test will be how many customers want both solar trackers and storage. Solar-plus-storage is trending up, and in the U.S., at least, most large solar installations favor tracking. The prospects there look good.

That leaves it up to NEXTracker to prove that those customers would rather buy both from the same vendor.