September 24, 2024
In Episode 22 of Power Players by Origis®, host Michael Eyman discusses some of the causes of solar asset underperformance and how to address it with Rhone Resch, President and Chief Revenue Officer of Solarlytics.
MEET THE PLAYERS
Often referred to as the “voice of solar energy in America,” Rhone Resch has 18 years of experience working in solar energy. He currently serves as President and Chief Revenue Officer for Solarlytics. Previously, Rhone was President and CEO of the Solar Energy Industries Association (SEIA), the national trade organization for America’s solar energy industry. He sits on the Board of Directors for SunWorks and Bright Night Energy.
With twenty years of leadership and operations experience, Managing Director Michael Eyman ensures that Origis Energy Services’ rapidly growing solar and energy storage portfolio performs as projected for owners and communities.
Latest kWh Analytics Solar Risk Assessment Report
Each year, kWh Analytics releases a Solar Risk Assessment report, partnering with industry experts in renewable energy to advance the solar and storage industry.
The 2024 edition featured contributions from Kiwa PVEL, Waaree, Alliant Power, Longroad Energy, Nextracker, Solarlytics, Univers, Clean Power Research, SolarGrade, Lloyd’s, Powin, and SEVO IFP.
The Solarlytics contribution authored by Rhone Resch, “Voltage collapse can reduce production by more than 20%,” sheds light on the issue of asset underperformance at the DC level.
Rhone Resch joined host Michael Eyman to discuss the issue across the industry. “Last year’s report showed that utility-scale assets are underperforming by 8% on average,” said Resch. “That means half of them are performing worse than 8% under their P50 levels, which is abysmal if you think about it from a power sector technology industry.
“By kWh illuminating [the issue] it creates a platform for different companies and research groups to identify what they see is happening in the field. We participated this year to talk specifically about what we call voltage collapse.”
Resch defined voltage collapse as “when the solar array peak power voltage becomes misaligned with the inverter’s operating range. This is a problem as the solar array ages and modules degrade, especially during warm weather when solar modules overheat. Voltage collapse is also found on newer installations that experience wide temperature fluctuation over the year. As temperatures continue to rise, voltage collapse is becoming a significant performance issue across the country.”
Eyman elaborated on the voltage window inverters and converters are designed for, “What you’re talking about is dropping out of the bottom of that voltage window or even being near the bottom. If you’re anywhere near the bottom, clouds or anything passing over are going to cause a shutting on and off of that inverter as it basically sees the thing and says, ‘Hey, you dropped out of the bottom. I’m going to shut down. Oh, wait, you’re here. I’m going to start up again. Wait, you dropped out again. Wait, I’m going to start up again. Wait, wait. No, oh, oh, oh, oh.’ And it’s back and forth, right? That’s really noisy data. It’s really inefficient and it can really affect production.”
The result can be inverter failure, but the real culprit is voltage collapse.
How to Address Underperformance at the DC Level
Resch believes the solution, especially for older assets, with a combination of old and new equipment operating on the same array, is to boost DC voltage. This approach averts cost prohibitive AC side applications.
Resch explained, “A technology like ours, and there’s others out there, which balance those strings, will let you have brand new 600-watt modules sitting right next to the 300-watt modules all feeding into the same inverter. That’s a pretty unique solution because we haven’t been able to do that previously. When you had broken modules, either you were taking a couple of strings off or you were restringing completely, which is super expensive, or frankly, you had mismatched strings. And that creates all sorts of problems, obviously, with respect to performance.”
By addressing the performance of older assets and repowering them on the DC side, Resch says the industry can extend the life of solar assets, “It is great that we’re building a lot of new plants, solar, wind, and other technologies. It’s fantastic. Let’s keep doing that.
“But it’s also imperative we keep every asset we have right now connected to the grid operating at the maximum level possible. And that’s what we’re trying to do, is make sure the asset base continues to produce so we can hit those RPS targets so solar and other renewables are considered reliable, and considered something we should be investing in.
“We are at a pivotal point right now in the industry where investors and some policymakers are questioning, did we make the right move by investing so heavily in renewables? And I think the answer is going to be yes.”
Eyman agreed, “It’s a fair question. We as an industry have to be able to answer those questions and be accountable.”
Conclusion
Eyman summarized owners would do well to partner their O&M contracts with companies that can analyze power quality.
“These sorts of effects are below the line of day-to-day operations,” said Eyman. “O&M is [typically] about keeping the site up and running. Analyzing at this level is really an engineering activity, outside the scope of break, fix, preventive maintenance, ancillary, and typical O&M services.
“O&M operators need to have partnerships. They need to be working with their owner and saying, ‘There is this unexplained loss bucket here we need to attack. And maybe we need to bring somebody in to look at the quality of the power on the site, which is really at a lower data level and requires some specific expertise.”
Resch agreed, “We, as an industry, have a responsibility to make sure things are working to the optimum level possible. There is a lot of money being left on the table if we do not go out and fix up these existing assets.”
During their conversation, Resch and Eyman discussed some of the causes of solar asset underperformance and how to address it.
Three key takeaways:
- Owners, especially those of older assets, are concerned about underperformance at the DC level, which can be caused by string imbalance, voltage collapse or lack of data.
- Underperformance is costing the solar industry Billions of dollars in unrealized production, and reputational harm when investors do not realize promised project ROI.
- The tech solutions required to mitigate underperformance are rarely accounted for in a typical O&M contract but should be to maximize asset performance.
We’d like to thank our Power Players, expert guest Rhone Resch and host Michael Eyman, for their insightful conversation, shedding light on addressing asset underperformance.