Thirty years is a long time to be engaged in any industry, but it’s an extraordinary amount of time to have dedicated to the solar industry. That type of commitment requires the patience of Job, and both a vision and commitment that few individuals possess. Dan Shugar, CEO of NEXTracker – a company that designs, manufactures, builds and services single-axis solar tracking and energy storage systems – is one of those few individuals. Shugar has stuck with the solar game since the early days when he and his colleagues at Pacific Gas & Electric were working to solve a challenge related to solar trackers. They introduced the concept of backtracking and developed the first algorithm to increase the solar energy collection on a given tracker array and to avoid shading losses that occur with conventional single-axis tracking.
That was then, and this is now: This past week NEXTracker announced that it had surpassed the milestone of contracting 20,000 megawatts (MW) of smart solar trackers globally. The company continues to remain the world leader in tracking systems and has doubled its manufacturing capacity over the past year to 300 MW per week.
Technologies will improve and prices will continue to fall
With his power industry and renewable energy domain expertise, Shugar brings a wealth of knowledge to the conversation, providing perspective both on where the industry has been, and where it may be headed. In discussing the future, he says, it’s helpful to peer back along the trail already traversed. He recalls completing the Nellis Solar Power Plant project over a decade ago (at the time the largest U.S. solar plant) that came in at $7 per watt, generating electricity at a cost of 25 cents per kilowatt-hour.
A lot has changed over that timeframe, with technologies and reliability that are now far superior. “Here we are 10 years later, and literally solar is one-tenth the cost of what that system was contracted and commissioned for.” Looking into the future, Shugar confidently predicts, ongoing cost reductions will continue to be “a sure thing.”
He observes that 10 years ago, the goal was to make solar the largest source of new generation installed in the U.S. Today, he states, that objective has been achieved, and the next step is to transform solar into the largest overall source of energy generation in the U.S. “That’s our North Star. That’s the next big milestone for the industry.” With declining capital costs and relatively modest operations and maintenance requirements, the levelized cost of energy (LCOEs) will continue to fall. Even today, the unsubsidized LCOEs compare quite favorably to conventional generation, including gas fired combined cycle plants.
Dealing with the dreaded duck
But how does one achieve that ambitious goal, given solar’s production profile that starts in the morning and tails off in the late afternoon? At some point, don’t grids reach solar saturation, and aren’t we all eventually headed for California’s ‘Duck Curve?’
Shugar acknowledges the concern, but points out that numerous pieces of the puzzle are starting to come together to address those issues and greatly increase the amount of low-cost solar that can be integrated into the system.
First, he says, there’s energy storage, a solution that is growing rapidly (analyst Wood Mackenzie’s recent Q1 2019 update forecasts a doubling of storage this year, with rapid growth in the coming years). Shugar is confident that battery storage will become increasingly important. However, he suggests that to look at storage alone is to miss the critical bigger picture.
In addition to storage, a growing constellation of price-elastic devices on the customer side of the meter can be connected and leveraged for flexibility. For example, vehicle-to-grid (storage on wheels) may emerge in the near future. At a minimum, managed charging can ensure that vehicle charging is optimized in its interaction with the grid. There is also air conditioning load that can be cycled. And finally, there is an enormous fleet of refrigerators and water heaters residing in every household across the country, devices whose thermal inertia can be leveraged through simple load control if and when it becomes cost-effective to do so. Shugar points out that all of this becomes significantly easier to manage with today’s communications technology. “The whole emergence of low-cost radios with Bluetooth and other technology…can massively facilitate intermittent renewables.”
Extending the grid itself also helps with integrating additional solar and wind projects, since it increases the diversity of resources across a wider geographic base. This reduces exposure to location-specific intermittency and allows for wind and solar output to be sold across a broader market. Peaks in demand occur at different times, weather varies over regions within that broader market, and the renewables spread across the geography have different production profiles.
Shugar sees grid expansion as the “next bastion of opportunity as it relates to regionalization in utility planning,” and points to regional transmission operator PJM (serving 65 million customers across 13 states and Washington, D.C.) as a model for how broad these grids can be. California’s Energy Imbalance Market provides another example of how broadening the market improves the ability to integrate renewables, and SPP just announced in mid-June its proposal for a Western Energy Imbalance Market, to be launched in December of 2020.
Adoption of regional integrated planning and Day-Ahead dispatch can also facilitate lower costs for customers and improved integration of renewables (ISO-New England just adopted new requirements to make this happen in its grid).
In some regions, a mix of different renewables can help improve integration opportunities. For example, nighttime wind can help to balance out the contribution of daytime solar (especially in Texas, where the profiles of daytime solar and night-time West Texas wind are relatively complementary). Indeed, Shugar comments that he is beginning to see “hybrid products where solar and wind get combined as integrated renewables.” And this is where storage is playing a pivotal role and unlocking variable renewables as reliable generation.
Evolving the technology to meet market needs
What about the ability of solar to provide energy during cloudy days or long-term inclement weather, such as a week-long ‘atmospheric river’ that occasionally affects parts of California? Shugar says that NEXTracker has been working to address just this type of problem, and that its TrueCapture product can increase output on cloudy days. “We monitor the atmospheric conditions in real-time and adjust the angles of panels…if panels are moved closer to horizontal there’s a significant increase in the amount of power.” In fact, he characterizes the difference in output between a normal panel tracking at 50 to 60 degrees on a cloudy afternoon and one that is close to horizontal as “actually double digit.”
NEXTracker’s core technology was developed in response to the real world, which generally does not behave the way solar developers would like it to. It doesn’t offer flat sites that are perfectly constructed, enjoying constant sunny weather. The company, therefore, created the algorithms and technology to improve the ability of flat panels to harvest sunlight. Shugar indicates that every row of panels has “lots of intelligence embedded in it,” including inclinometers that communicate the panel angles, and a wireless mesh network that facilitates a high degree of connectivity among thousands of devices in the field that speak to each other (introduced five years ago, NEXTracker now has over half a million trackers in the field using this technology).
“Using that foundational architecture, we were able to layer the TrueCapture adaptive tracking system on top,” Shugar says. “Today, sensors provide real-time shading information for each row, which is then transmitted to machine-learning software that constructs a 3D model of the site, integrates the most recently available meteorological data, and sends commands back to each row so that the entire system is optimized for maximum energy production.”
The concept for TrueCapture had been in the works for some time, being extensively tested and validated by independent engineers prior to commercial roll-out. Although gains vary somewhat by system, Shugar indicated that his company can show clients the difference in output with and without NEXTracker. He quantified the percentage improvement at 2-6% for typical sites, and he commented that returns on investment are “materially improved.”
The company has already seen significant uptake of TrueCapture. Private developer Invenergy recently announced a 160 MW solar project in Georgia that utilizes TrueCapture in conjunction with bifacial panels. Shugar noted that other clients have retrofitted TrueCapture onto existing panel fleets, with one major South American customer, Atlas Renewable Energy, integrating it into a half-dozen facilities.
What the future holds, more innovation, lower costs, and big growth in bifacial
Shugar says that this type of innovation is critically important for the company and the industry’s continued ability to grow at scale. For continued success, he states, “It comes down to providing more energy at lower cost, with stronger reliability.”
What does NEXTracker’s CEO see on the horizon? For the company, a continued relentless focus on innovation: “More revenue allows us to do more R&D – success begets success – so you can have sustained innovation and R&D.” For the industry, he expects to see a big increase in the deployment of bifacial panels (which were just exempted from import tariffs).
This technology is not new. In fact, Shugar notes, “NEXTracker’s core product, NX Horizon, was conceived as a bifacial-optimized tracker,” and the company already has more than 1,000 MWs of bifacial in construction and fulfillment. What has changed, he says, is that solar panel manufacturers can now make bifacial panels at scale with very low incremental costs. That’s because solar cells have improved greatly in recent years, with better and purer silica material. Wafers have become thinner, at 150-micron thickness compared with 300 microns or more in the past. Meanwhile in monosilicon panels, PERC (passivated emitter rear cell – where the sunlight passing through is reflected back, generating more electrons rather than waste heat) has yielded solid results. At the same time, panel glass has become both thinner and stronger.
Thus, the resulting incremental cost to manufacture bifacial panels is relatively small. As a result, “you are seeing multiple manufacturers introduce multiple panels which are bifacial. We see it going from utility-scale applications at roughly 15% today to 50% within 3 years, just as a rough forecast. It’s a huge deal.”
Anticipating this trend NEXTracker has invested in R&D accordingly, testing bifacial panels in its Center of Solar and Storage Excellence. The company recently ran a large experiment with 20 controlled bifacial panels running side-by-side to demonstrate gains in the field, working with developers, banks and engineers to optimize and verify the results. Shugar indicates the company is now “taking it to the next level, collaborating with several module manufacturers to further optimize.”
Shugar cautions that the industry should also pay attention to thin film and First Solar. “I visited Perrysburg, Ohio (First Solar’s upgraded manufacturing plant). I was totally blown away by what I saw.” The Series 6 represents a “quantum leap in efficiency and mechanically optimized size,” with impressive manufacturing efficiencies. “The promise of thin film was always there, but needed to improve for efficiency, mechanical, size and packaging. FirstSolar has solved those issues, and we have optimized a tracker around that.“
Irrespective of the panel technology, the next step for NEXTracker is to continue developing and operating systems as an integrated plant, with a fully optimized systems approach using both hardware and software to deliver the most value possible, integrating storage to drive the expansion of solar into the grid at large. “The advent of the smart power plant, that’s really what we are working on,” he says.
Shugar sums up the future of the industry with his characteristically sunny optimism. “We have challenges, but I don’t see those as impediments to solar being the largest source of generation on the grid.”