Close the Gap: How to revive lagging large-scale PV project performance

Alencon’s SPOT X2 DC-to-DC optimizer

Alencon’s SPOT X2 DC-to-DC optimizer can boost utility-scale PV plant performance.

A completed PV project is like a splashy free agent sports signing. Everyone is all pumped up at the ribbon cutting or press conference, but if it underperforms and misses expectations, that goodwill is gone. Live up to that contract or get booed.

In a world where new utility-scale projects might slow down (a possible understatement if tariffs are placed on module and cell imports), optimizing current portfolios is crucial, not just for each project to hit its targets, but to continue to prove solar as a worthy investment and distributed resource.

Closing Performance Gaps

With more than a decade of hardcore O&M industry experience, there is a greater reservoir of institutional knowledge both out in the field and in plant operation management. For example, MaxGen is a U.S.-centric O&M provider focused on utility and C&I sites that manages a large team of licensed, professional technicians throughout the country, hitting about 5,000 different sites a year for corrective (CM) and preventive maintenance (PM).

As part of its business model, the company will take over portfolios of assets to monitor — some of which are underperforming. According to Mark McLanahan, CEO of MaxGen, assets are usually underperforming because of one or more of these reasons:

  1. The site is not in good physical condition because of poor vegetation management or erosion or general site management. Consider this a reminder to keep O&M in mind when designing a project because it is often the largest expense over the life of the project. “Handling stuff like vegetation management and module washing can be the biggest expense by far if you’re not careful,” McLanahan says.
  2. Poor PM records, which often means PM hasn’t been done. “That’s a problem because you have to perform PM to maintain warranties of inverters, combiners and modules,” McLanahan says. “We have seen many cases where service to date is either not verified or there’s no record.”
    This is where PowerFactors comes in handy. PowerFactors is an energy operations management software platform that MaxGen has been using since 2016 to integrate all the monitoring, alarm management, work order creation and management, dispatch and reporting for all the operations, and preventive and corrective maintenance tasks in its scope of work with its customers. Also, contract requirements can be programmed into the system. For example, Power Purchase Agreements in California often require instant notification of large drops in capacity and failure to do this will incur penalties. Auto-notifications can be routed to the right places in those events with the right rules plugged into the software. This enables fewer operators to manage more projects with greater complexity.
  3. The site data acquisition system simply hasn’t been mapped properly, which undermines the data quality of the entire project and leads to maintenance misdirection. There’s an outage on inverter A; a dispatched technician heads to inverter B because it’s mapped as inverter A. The issue isn’t discovered, and so on. McLanahan estimates that MaxGen encounters this in 20 to 30 percent of the underperforming sites it takes over.
    “It’s a data quality issue,” he says. “With solar, you have to study performance at the low level, not just the revenue meter, to make decisions on performance. You have to look at inverters or combiners or at the main circuit. If the mapping is no good, you’re wasting time.”

Once the site is remapped and the PM is up to date, annual maintenance and CM plans are put in place to build it back to baseline performance using better data. From there, more advanced decisions can be made. Data can be studied for factors such as ground coverage ratios, tracker angles, performance anomalies at the combiner level and similarity-based modeling to help identify additional opportunities. MaxGen has boosted a number of utility-scale projects 2 to 5 percent on the performance side using this systematic process.

“With consistency, you’ll see 1 to 3 percent improvement right off the bat just with low-hanging fruit,” McLanahan says. “Compare the combiners on a relative basis on performance and just look at last month. That sets the corrective maintenance for the next week. Once you have accomplished all the PM tasks, have good data access and capture the low hanging fruit, you can move up the lost energy priority list and tackle the things that are above the baseline to increase production and revenue even further.”

Solar for All: How to incentivize community solar projects to benefit low-, middle-income customers

Retrofitting or Repowering?

Traditionally, the two options for a lagging PV site to hit its expected performance target are: 1) boosting its actuals, or 2) lowering the expected numbers.

“Once a project has been reviewed to ensure all the basics are correct, we can focus on boosting output to outperform proforma expectations. Part of this process sometimes includes resetting the baseline based on correcting performance assumptions made before the plant was built,” McLanahan says.

Obviously no one wants the latter, but overestimates happen frequently during the high-stakes, quick turn-time bidding process via incorrect assumptions regarding soiling, degradation, line losses, etc.

But, what if there was a way to still overachieve from the original estimates? This is the proposition presented by large-scale, DC-to-DC optimizers just now coming onto the market as part of a retrofitting strategy. The Alencon SPOT X2 is one such optimizer that has been recast in a manner to make it easier to minimize the soft costs — such as labor and ancillary installation materials — associated with PV retrofits. Minimizing installation costs is key to achieving the highest rate of return on PV retrofits, and retrofitting a PV plant with Alencon’s SPOT can significantly increase PV yield by introducing more granular MPPT while at the same time improving safety and decreasing on-going O&M costs.

“With a number of PV assets now changing hands as PV plants get older and PV fleets get consolidated, we are seeing a great deal of interest in retrofitting PV plants to improve energy yield. The SPOT X2 makes performing larger commercial and industrial or utility scale PV retrofits much easier than ever before,” says Hanan Fishman, president of Alencon Systems.

Now, retrofitting a large-scale PV system with new equipment is a tough sell because the profit margins are thinner and ROI is tighter than new construction (plus the downtime that must be factored in), but going this route with an experienced team could prove valuable. Energy and electrical systems specialty firm ProtoGen, for example, has executed a number of retrofit projects and incorporated Alencon’s SPOT DC optimizer at the string level to minimize those retrofit costs because it’s as close to a plug-and-play PV retrofit solution as possible.

“The key to pulling off a PV retrofit in a cost and time effective manner is to think in terms of 80 percent planning and 20 percent execution,” Fishman says. “In our experience, if you can maintain that proportionality, you should be able to set a similar target for your percentage of hard costs to soft costs.

Here’s a checklist Alencon suggests using if you are considering a retrofit for a large-scale PV project:

  1. How much is the equipment going to cost?
  2. Have I considered all the elements of ROI that go into the project including production incentives and potential tax credits like accelerated depreciation?
  3. What sort of engineering analysis will I need for the project? Structural? Electrical? Anything else?
  4. Will the work require a permit? If so, who is the AHJ? What do they need to approve the project (i.e. stamped and sealed drawings or just a statement of work)?
  5. What sort of certifications will be needed for the equipment being installed (i.e. UL or NEC)?

Bottom Line

The true bottom line in PV system performance, from initial projections to 30 years in the future, is customer service. People need to make the correct assumptions, perform all O&M tasks correctly and use data analysis to their advantage while being as proactive as possible. As more data is gathered and algorithms are perfected, “trend events” will be the next frontier for improving performance.

“These don’t show up as a discrete one-time energy loss but as small events that happen continuously over time, and if you don’t look for them you won’t see them,” McLanahan says. So, maybe one inverter is coming on and offline in mere seconds. “If you look at the curve, you won’t see it, but if you look at the trend, there’s something wrong with that inverter, and it will likely break down at some point.”

That curve is a nice visual to end on. Just plan to stay ahead of it.


 

Speaking of data…

Chris Crowell and Kate Trono, VP of Products for SunLink

Craving some more nerdy solar data talk? You’ll want to check out our new podcast — Solar Builder Buzz — in which we grab a beer with people smarter than us to discuss the solar industry. In Episode 2, we sit down with Kate Trono, VP of Products for SunLink, and pick her brain on the value of data in the solar industry and just where the industry is going (and should be going) from here. We maybe also discuss Sci-Fi.

Listen to the pocast here.


 

Take a quick peek

Measure launched new turnkey solutions for solar facility owners

Measure launched new turnkey solutions for solar facility owners, asset managers and O&M contractors that include drone-based site overview and maintenance, site shading and terrain analysis, thermal inverter scans, tracker misalignment detection and vegetation management. On a site generating 21 MW, for example, Measure can complete an inspection in seven hours instead of weeks, freeing employees and contractors for higher-value activities while also lowering inspection costs. The lower cost also makes it possible to perform more frequent inspections that can detect problems in a timely manner.

Maximum revenue capture for larger plants may not be inspected in a single visit and potentially leave some issues or faults unidentified. Measure’s launch customer was able to avoid a potential revenue loss through an inspection that discovered over 200 malfunctioning panels on a new solar farm.

— Solar Builder magazine

New stuff from Tigo: three Duo covers, partnership with SMA

Tigo, a pioneer of the smart modular Flex MLPE platform, is always announcing new products and partnerships. Here are the latest:

Three new Duo covers

Tigo MLPE

These three new “Duo” covers are  add-on / retrofit solutions for its TS4 platform:

  • TS4-R-O-Duo (Optimization),
  • TS4-R-S-Duo (Safety), and
  • TS4-R-M-Duo (Monitoring).

The TS4-R-X-Duo brings smart module functionality to standard PV modules, adds smart features to new PV installations and upgrades underperforming PV assets. With UHD-Core technology and expanded specifications, the Duo supports two PV modules connected in series with a combined power of up to 700W and a combined voltage of up to 90V.

With a universal base and a range of covers containing flexible module-level power electronics (Flex MLPE), Tigo’s Duo increases freedom of choice when selecting features for a particular project and budget. All three Duo covers work with any inverter and any module within its electrical specifications.

Partnership with SMA

Tigo and SMA are joining forces to deliver total compliance with the newly released SunSpec Alliance specifications regarding Rapid Shutdown adoption for PV plants. SunSpec Alliance, certifier of PV components and communication standards, has defined the specifications of the powerline-based PV transmitter signal covering varying installation types and regions.

Tigo and SMA’s partnership brings the first transmitter and receiver offering that represents interoperability between the inverter and the PV module’s MLPE. SMA’s full line of US string inverters will be supporting the new SunSpec standard to fulfill the tightened module-level requirements in National Electric Code (NEC) 2017, becoming mandatory in January 2019. Tigo will expand its current offering to include a SunSpec Rapid Shutdown and add this capability to its TS4 Flex MLPE product line. The new addition is 100% compatible and certified by about 40 PV module suppliers currently using the TS4 platform – including Trina Solar, Itek, and Sunpreme. The new offering is also available for add-on or retrofit applications.

2017 Solar Inverter Buyer’s Guide

 

— Solar Builder magazine

Tigo solidifies rapid shutdown certified partnerships with more than 35 inverter types

tigo ts4 mlpe rapid shutdown

Tigo, pioneer of the smart modular Flex MLPE platform, has boosted its portfolio of international inverter partnerships to more than 35 inverter-types that are now Rapid Shutdown certified by Underwriters Laboratories (UL).

SMA was first to adopt Tigo’s portfolio of Rapid Shutdown certified offerings. Additional commercial and residential inverter suppliers that also received the UL certification include:

  • ABB,
  • Fronius,
  • Ginlong Solis,
  • Kaco,
  • Sungrow,
  • Yaskawa – Solectria Solar,
  • and more.

Inverters ranging from 3kW to 30kW are certified with Tigo’s TS4 optimizers with UHD-Core technology and are shipping now. This brings the largest Rapid Shutdown solution offering with the widest adoption to market – providing Installers, EPC, and Owners the most cost-effective response to the NEC 2014 & 2017 code requirements.

“Customers looking for cost effective solutions that comply with strict safety regulations have a solution available. With Tigo’s UL Certification, our partners are exceeding these standards,” said Zvi Alon, CEO of Tigo. “We are excited to add more brands to the most diverse portfolio of approved partners in the industry.”

According to UL’s certification Rapid Shutdown Systems requirements for Distributed Generation Power System Equipment, the rapid shutdown protection is intended to reduce potential hazards and limit exposure to energized PV wiring and equipment to allow emergency first responders to perform work outside the energized area of the PV array. Also, these high reliability PV rapid shutdown systems have a higher system fault tolerance and reliability to perform their intended function under foreseeable single-point component and system failures. Only systems found to comply with these additional functional safety requirements are marked “High Reliability PV Rapid Shutdown System.”

— Solar Builder magazine

Tigo’s TS4 MLPE platform earns UL certification for meeting rapid shutdown regs

tigo ts4 mlpe rapid shutdown

Underwriters Laboratories (UL) has certified Tigo‘s UHD-Core TS4-S for fully complying with National Electric Code (NEC) 690.12 Rapid Shutdown regulations. The TS4-S joins the UL Certified status of Tigo’s TS4-L (Long Strings) and TS4-O (Optimization) announced last February; all products are currently shipping.

The UL Certification now applies to 600V, 1000V, and 1500V PV system designs with Tigo’s TS4 MLPE modular platform using any type of module with a maximum output power of 475W. The built-in automatic over voltage and over temperature protections continue to reduce liability and improve the safety of installers, customers, and first responders in case of emergency.

“Tigo’s UL Certification enables our partners to meet NEC demands like module-level shutdown now, while also offering the most cost effective and flexibly designed systems on the market,” said Zvi Alon, CEO of Tigo. “

To see Tigo’s TS4 platform with a Sunpreme bifacial smart panel, visit Booth 8401 at Intersolar North America’s Exhibition in San Francisco on July 11-13, 2017.

Get to know NEC 2017 revisions: Updated PV labels, rapid system shutdown

 

— Solar Builder magazine

MLPE boom: Analysts expect big things from module-level power electronics market

The module-level power electronics industry is witnessing an intense growth phase. Demand is driven by increasing solar photovoltaic (PV) installations across the globe and modernization of grid infrastructure capable of accommodating module-level power electronics (MLPE) technology within the system.

APS PV Microinverter

Example of MLPE — APsystems microinverter

“With movement towards renewable power and distributed power sources, the MLPE market is expected to sustain further significant growth in all regions of the globe,” said Energy & Environment Research Analyst Manoj Shankar. “To gain a competitive advantage and increase market share in a highly consolidated and fiercely competitive market, MLPE companies must innovate their products to reduce prices, seek geographic expansion, and invest in partnerships or merger and acquisition strategies.”

Global Module Power Electronics (MLPE) Market, part of Frost & Sullivan’s Power Generation Growth Partnership Service (GPS) program, finds that the market is expected to grow from $648.7 million in 2016 to $1.16 billion in 2021 at a compound annual growth rate (CAGR) of 12.4 percent.

Other developments include:

• The residential and commercial segments will see rapid growth in the next three years due to new installations and low product prices.

• Rising installations of rooftop solar in Asia-Pacific, especially in China and India, will see the market moving towards Asia-Pacific from North America.

• Reduced MLPE costs will lead to a higher adoption in many developed and developing nations.

• Changes in government policy will aid the solar industry in new markets such as Latin America and Africa.

• The total MW-level MLPE installations are expected to increase from 3.3 GW in 2016 to 10.7 GW in 2021 at a CAGR of 26.2 percent.

• Enphase Energy and Solar Edge Technology Inc are the two major players that dominate the market due to their early mover advantage.

• Prices of microinverters and DC optimizers are expected to be on par in the near future with traditional inverters, leading to higher adoption by consumers.

• Competition from other technologies, increased usage of other sources of power, lack of protocol standards, and regulations and tariffs are key factors that are hindering growth in the market.

“Renewable energy targets and regulations are set to play a major role in the development of the MLPE market as countries move towards more efficient and sustainable power generation,” noted Shankar.

— Solar Builder magazine