Assessing Current and Emerging Technologies in Solar Energy

Posted on August 26, 2022January 12, 2023 by The Sol Systems Team

Assessing Current and Emerging Technologies in Solar Energy

Technology | 26 Aug 2022

By The Sol Systems Team

New technology and scale continue to drive advancements in renewable energy. This is an exciting time for solar technology, particularly as implementation of the Inflation Reduction Act (IRA) begins. Here, we highlight some of the market and current and some future technological trends in solar energy.

High Material Cost is Causing Strategy Adjustments for Developers

In June of 2020, previously record-low spot market prices for polysilicon began to rise, a trend we expect to continue into 2023. With it, the cost to build solar energy began to increase for the first time in a decade, and unexpectedly high procurement costs have left developers looking to reduce supply-chain and logistics cost, in part, by maximizing system capacity and size. As a result, the physical size of solar modules, along with the inverters, cables, and transformers necessary to facilitate them is increasing. Before we delve into the details, it’s important to understand the basic facts underlying new module technologies.

Mono-PERC Dominant as Bifacial Market Share Increases

In 2018, we wrote about how premium, higher-efficiency cell technologies, like monocrystalline PERC (mono-PERC) modules, were beginning to close the price gap with non-premium modules. The price gap is now non-existent, and mono-PERC cells dominated the market with a market share of 85 percent in 2021 (and likely much higher when considering only the U.S. market). Mono-PERC cells have impressive energy conversion efficiency that currently averages approximately 21 percent, and their consolidated market share has helped reduce cost at scale. In addition, roughly half of 2021 solar installations incorporated the use of bifacial modules, which only further increases efficiency of projects. Before 2020, bifacial modules only made-up approximately 15 percent of the overall module market, but is now expected to exceed 85 percent by 2032 (this should continue or even increase with continued exemption of bifacial modules from Section 201 tariffs). In brief, today’s utility-scale solar projects are now overwhelmingly using bifacial mono-PERC cell technology, considered a premium just a few years ago.

Decreasing Levelized Cost of Energy (LCOE) in the Face of Rising Build Costs

Increased module sizing has been key to bringing down the levelized cost of energy (LCOE) for solar, particularly in the utility-scale sector. In the second quarter of 2022, modules with 182 to 210 millimeters (mm) sized cells accounted for 80 percent of module shipments. The increase is notable when compared to 2018, when the previous standard 156.75 mm cells dominated the market with an approximate 90 percent market share. Developers that were installing 400 to 450 watt (W) modules in recent years are now routinely installing 600W or larger modules, and the modules with 210 mm cells alone are expected to reach 56 percent market share by 2023.

The implementation of larger-format modules results in changes to the equipment, cost, and overall layout of a site. The use of larger modules typically results in the need to upscale other equipment, such as racking systems. This can lead to an overall reduction in LCOE of the project, as developers are able build larger capacity systems using larger components that require less labor, transportation, and operations and maintenance (O&M) costs. As module sizes increase, however, installation will eventually become more difficult and single-axis trackers will require thicker foundations and torque tubes to maintain structural stability under increased wind loading. Thus, over the longer term we expect a plateau to size increase and a continued focus on efficiency improvements. In the meantime, larger-format modules are helping utility-scale projects pencil in the wake of an unusually expensive market.

What does Tomorrow’s Solar Look Like?

While we can expect the continued adoption of larger format bifacial modules in the near term, emerging technologies continue to seek market share in the coming years. Two versatile technologies peak our interest: perovskite-based solar cells and luminescent solar concentrators.

Perovskite solar cells are an emerging thin-film cell technology built using the calcium titanic oxide mineral perovskite rather than silicon. Following years of fast improvement, researchers recently achieved efficiencies greater than 30 percent in lab environments by combining perovskite with silicon in what are called tandem cells. This flexible, lightweight, and high-efficiency technology offers appealing potential in a variety of applications ranging from buildings to vehicles. While lab results are promising, the technology faces many barriers to commercial viability. Perovskite-based cells have long suffered a high rate of degradation, and solving the technology’s durability issues will be key to its prospects of competing with current technologies that continue to extend project lifetimes. While the technology has the potential to be relatively low cost, it has yet to pave a clear path to a commercially viable product that can be manufactured at scale.

While perovskite technology is an example of a new, highly efficient solar cell that is achieving impressive results in ideal lab conditions, technologies like luminescent solar concentrators (LCSs), which use existing cell technology present an interesting near-term opportunity. In a lab testing environment, LCSs achieves ideal results by concentrating the highest magnitude of irradiance directly perpendicular to the cell. In other words, direct sunlight which is far from field conditions. LSCs, however, can efficiently convert irradiance in the field regardless of magnitude or angle of incidence through solar concentration.

A diagram illustrating how luminescent solar concentrators work – Credit: 4TU

LSCs look like a translucent, usually colorful, piece of plastic that glows slightly around the edges. Whereas solar modules absorb light directly into the cell at the angle the sunlight hits it, LSCs absorb incoming radiation into the material, trapping it there through a phenomenon known as total internal reflection. This trapped irradiance (concentration) is then concentrated directly in solar cells at the edge of the material, giving it the ability to harness diffuse irradiance similar to lab conditions.

Because of its ability to efficiently convert diffuse irradiance into electricity, as well as its largely transparent material, LSCs are becoming a more practical and less expensive way to integrate solar cells into applications like windows. This could allow solar generation using a building’s façade rather than just its roof. Additionally, recent breakthroughs in “quantum dot solar concentrators,” provide a longer life and a wider variety of colors for LSCs, which could lead to a clearer path for future commercial viability.

Scaling the solar industry at a rate necessary to succeed under the Inflation Reduction Act (IRA) will require increasingly innovative solar design and deployment. We look forward to keeping you updated as technology continues to evolve.

GETting from Here to There: Grid-Enhancing Technologies Mature

Posted on August 26, 2022January 12, 2023 by The Sol Systems Team

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GETting from Here to There: Grid-Enhancing Technologies Mature

Technology | 26 Aug 2022

By The Sol Systems Team

One notable challenge of the American energy transition lies in modernizing the transmission grid at a pace that reliably integrates the enormous growth of clean and renewable energy. With federal clean energy investments like the recently-signed Inflation Reduction Act (IRA) incentivizing the development of wind and solar power projects faster than the grid can expand, new grid-enhancing technologies (GETs) can offer a bridge between the speed of generation built and the ability of the grid to catch up. Simply put, in the decade that it takes to build new transmission lines, GETs can be deployed in a matter of months and alleviate grid congestion keeping renewables in the queue. One such technology, dynamic line ratings (DLRs), has the potential to ease congestion on transmission lines and enhance safety and reliability by improving the accuracy and transparency of line ratings. Not only would these improvements provide much-needed consumer savings, but they would reduce the cost and increase the speed of interconnecting more solar and wind power resources as well.

For decades, many North American transmission operators have used static line ratings (SLRs) to determine the maximum power flow capacity on a transmission line. Appropriate for the mid-20^th century grid, SLR calculations use intrinsically conservative assumptions regarding atmospheric operating conditions to produce transmission constraints that vastly underestimate how much power lines can carry. Using modern computing power and digital monitoring, DLR systems, by contrast, paint a more accurate picture of transmission line capacity by accounting for the role of real-world conditions such as rain, air temperature, cloud cover, and wind speed. This ambient approach to grid management can both reveal significantly greater transmission capacity than previously presumed while also detecting situations where flows should be reduced for safe and reliable operation.

As the demand for clean electricity continues to grow, misaligned regulatory and economic incentives have caused transmission gridlocks with multibillion-dollar congestion costs while also preventing the interconnection of over 70 percent of the new renewables and nuclear capacity needed to hit climate targets set by the Biden Administration and a growing number of states. On February 17, 2022, the Federal Energy Regulatory Commission (FERC) launched an inquiry aimed at evaluating the benefits, costs, and challenges of DLR implementation. Furthermore, several utilities like New England’s National Grid and New York’s Power Authority have begun piloting DLR systems on transmission lines across their service territories. The recently passed Inflation Reduction Act, with its long-term solar and storage tax incentives, serves as further evidence of the tide turning toward a future beyond wires that includes a broader range of transmission technologies. No one is touting GETs as the panacea to the climate crisis nor is their optimal deployment as simple as dropping DLR systems on every transmission line. Not up for debate, however, is that grid capacity must expand in coming years to integrate an ever-evolving resource mix efficiently and reliably. To that end, grid-enhancing technologies present a viable alternative capable of spurring the cost-effective transmission infrastructure that will help decarbonize the electric grid with significant clean energy deployment.

Battery Storage is the Way of the Future: Have You Accounted for the Right OpEx in Your Financial Model?

Posted on June 3, 2022January 12, 2023 by The Sol Systems Team

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Battery Storage is the Way of the Future: Have You Accounted for the Right OpEx in Your Financial Model?

Technology | 03 Jun 2022

By The Sol Systems Team

Most solar developers around the world are rushing to add lithium-ion battery storage to as many projects as possible and to update financial models to account for the added development and OpEx challenges they present. Without many operating batteries on the market, many developers and owner-operators (Sol included) are continuing to update their OpEx assumptions. Public reports, such as this 2020 NREL forecast for commercial-scale battery storage, provide forecasts for how fixed O&M costs will decline over time, but these projections are difficult for developers to integrate into project economic models without more operational data. Even the few public reports published in 2020 and 2021 include not only a range of published O&M costs—see the table below for a few examples—but also report significant uncertainty on the scope of those examples.

2020 O&M Cost	BESS Size	Source
$1.921/kWh	100 MW / 200 MWh	Lazard’s 2020 Levelized Cost of Storage Analysis – Version 6.0
$1.04 - 1.26/kWh	1 MW/ 2 MWh - 100 MW / 200 MWh	Pacific Northwest National Laboratory 2020 Grid Energy Storage Technology Cost and Performance Assessment
$12.5/kWh $8.75/kWh	60 kW – 1.2 MW / 240 kWh – 7.2 MWh 60 MW / 240 MWh	NREL Storage Futures Study

While battery original equipment manufacturers (OEMs) and integrators can advise developers on what some of these costs might be, such as preventative maintenance or a Long-Term Services Agreement (“LTSA”) that includes an augmentation plan, many of these project costs are up to the developer to assess and to integrate into economic models. Battery energy storage systems (“BESS”) present a huge opportunity for the clean energy industry as deployment grows and hardware costs decline.

1. Auxiliary Loads: For technical and economic reasons, most often the thermal management systems and SCADA are served by a separate feeder, using retail power from the grid rather than the solar system. Auxiliary load profiles are hard to estimate and vary from project to project depending on precise cycling patterns and the applicable BESS product. Battery OEMs and integrators may not be able to provide these estimates early on, leaving developers struggling to include reasonable estimates in their models. Even Tesla Megapacks, known for their ability to use the battery’s own charge to power its thermal management system, still require some additional auxiliary loads (e.g., additional SCADA for the entire BESS). For most utility-scale battery systems, these additional auxiliary loads are separately served by their own retail meters.

2. 24/7 Emergency Alarming with the Fire Department: Many BESS integrators offer a basic preventative maintenance package that includes valuable alarming and forecasting of specific equipment deficiencies that could eventually lead to fires. The responsibility of contacting the fire department in the event of an emergency fire alarm, however, is still often passed around like a hot potato. For smaller developers without a 24/7 network operations center, this all-hours fire alarm notification requirement is something that they must be ready to cover themselves.

3. Climate-Controlled Spare Parts: Capacity Maintenance Agreements (CMA)[1] typically require the asset owner to purchase a specific list of spare parts. Make sure to ask for this list and associated costs in advance—because they can add up! However, some (e.g., the battery modules) require specific climate conditions and appropriate documentation of said conditions to maintain any applicable warranties. Luckily, they are the same as the operating modules require, so the simplest solution is to leave several empty racks and simply store the spare modules in the same enclosure as the operating battery (with a battery management system (BMS) to track conditions).

4. Install of Augmentation: The installation of the augmented BESS modules is often a forgotten scope item and uncounted cost in the initial pre-Notice to Proceed (“NTP”) financial model. Most BESS integrators are not prime construction/engineering contracting firms and treat the install and balance-of-system of the augmented BESS modules the same way as they do the initially installed modules, assuming that the developer or asset owner is responsible for install. Ensure that you don’t undercount the future cost of mobilization and lifting equipment rental. While this gives developers the flexibility to shop around for price, it leaves some uncertainty on the table as to what the cost of installing additional BESS units will be in 7–15 years. There are ways to construct the initial build with everything in place to make that mid-term augmentation as efficient to install as possible, but we are all making calculated assumptions about what the future install cost will be.

5. Non-BESS Equipment O&M: BESS integrators provide the BESS modules/enclosures, the inverters (PCS), and often the medium-voltage transformers. Beyond that, your EPC partner or in-house construction team will be procuring a much longer list of equipment, and the maintenance of this additional equipment is often a forgotten cost as well. If a BESS is paired with a solar project, the O&M provider for the solar project can typically offer this O&M for a reasonable additional cost. Alternatively, if the BESS is standalone, this additional O&M is both more expensive and can be harder to find—therefore, it is even more important to add these costs into the model early on.

6. Corrective Maintenance for Smaller BESS: For smaller BESS where a CMA doesn’t make sense economically, integrators and BESS vendors provide a wide range of contract-term services, and it can be hard to parse through different defined terms from different vendors and evaluate if they are covering equivalent scope. Most offer preventative maintenance that is explicitly mentioned in the BESS proposals, but the corrective maintenance is frequently left out of many offerings for smaller projects (or the costs are ‘TBD’ depending on the future number of corrective maintenance events) and can easily be left out of an early-stage financial model if the developer isn’t careful.

7. Extended Warranty: In addition to corrective maintenance, another sometimes-hidden cost is the warranty extension (which is typically named different ways by different OEMs). Different vendors include different warranty lengths with the system purchase, but there is typically a cost to extend beyond 15 years and often a cost to extend beyond even just 3–5 years. Failing to purchase this extended warranty for the full term of contracted revenue would leave an unthinkable scope gap that financiers won’t accept, and therefore, these warranty extensions are a need-to-have.

As the industry grows and matures, the standard OpEx assumptions for BESS projects will be easier to forecast and calculate. We are looking to add energy storage for all of our utility-scale and distributed-generation solar projects, and we are working with several customers on standalone battery opportunities. What is clear is that energy storage will continue to be a key aspect of project development and energy management going forward, and the Sol team is eager to work with our development partners and customers to create as many new opportunities as we can.

*Sol’s 5 MWh BESS + solar rendering in Holliston, MA for the Town of Holliston – Under development*

[1] A Capacity Maintenance Agreement (CMA) is a commitment by a BESS integrator to maintain a certain capacity from beginning-of-life commissioning through a full contract term (e.g., 20 years) using a combination of oversizing and augmentation.

Robots Roaming Around Solar Projects? Sol Systems’ Newest Tech Addition

Posted on July 1, 2021August 12, 2021 by The Sol Systems Team

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Robots Roaming Around Solar Projects? Sol Systems’ Newest Tech Addition

Sustainability | 01 Jul 2021

By The Sol Systems Team

The robots are coming...to our solar sites! This spring, Sol Systems installed robotic mowers at its 1 MWac project in Rock Falls, Illinois to assist with vegetation management.

For Rock Falls, Sol Systems collaborated with the Langton Group, the Midwest arm of Automated Outdoor Solutions, to deploy robotic mowing solution at the site. Each of the five robotic mowers managing the site runs up to ten hours a day, mowing its section of the six-acre project. The mowers are self-sufficient and can dock in their stations to charge as needed. The mowers’ constant maintenance means that site vegetation is always under 6 inches in height.

As is common with solar projects, we must properly manage onsite vegetation (a fancy way of saying mow the grass) in compliance with the City. Sol regularly reviews different vegetation management options for our projects, which, in addition to traditional grass mowing, now include recent industry innovations such as native habitat, sheep grazing, and robotic mowers.

Ultimately the decision to proceed with robots came down to a combination of sustainability, economics, and a desire to better understand how robots would perform in the field. Although the robotic mowers are not 100% carbon neutral, they were the most effective and most sustainable solution to properly manage the project. We’re always excited to incorporate a new strategy to our vegetation management portfolio, which includes a growing number of pollinator habitats and now, robots.

About Rock Falls

Sol Systems installed the Rock Falls project in late 2020 with the Illinois Municipal Electric Agency (IMEA). Through a 20-year power purchase agreement, Sol Systems developed the project with zero upfront costs and helps IMEA place solar on the grid while diversifying its energy supply. This 1 MWac ground mount project spans over 6 acres on the city’s land and produces approximately 1,780,200 kilowatt hours each year, providing enough power to serve 170 Rock Falls residents. This project helps IMEA offset 850 tons of carbon each year.

About Sol Systems

Sol Systems is a leading national solar energy firm with an established reputation for integrity and reliability across its development, infrastructure, and environmental commodity businesses. To date, Sol has developed and/or financed over 1 GW of solar projects valued at more than $1 billion for Fortune 100 companies, municipalities, counties, utilities, universities, and schools. The company also actively shapes and trades in environmental commodity and electricity markets throughout the United States. The company was founded in 2008, is based in Washington, D.C., and is led by its founder. Sol Systems works with its team, partners, and clients to create a more sustainable future we can all believe in. For more information, visit https://www.solsystems.com/

How to Deliver Solar Safely, Soundly, and Successfully during COVID-19

Posted on May 28, 2020January 12, 2023 by Sintia Torres

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How to Deliver Solar Safely, Soundly, and Successfully during COVID-19

Technology | 28 May 2020

By Sintia Torres

In any scenario, the construction phase of a solar energy project brings with it a slew of logistical challenges and decision points for the delivery team. During the COVID-19 crisis, that list has understandably grown. COVID-19 has impacted all aspects of construction, both administrative and in the field. Where solar construction activities have been allowed to continue, thinking about and planning for procurement, permits and interconnection, host considerations, construction on site, and commissioning are all key to minimizing project delays.

Below are a few considerations to keep in mind during COVID-19 to help maintain schedules while implementing protocols that minimize safety risks for those involved. Note that this list of considerations is non-exhaustive, but it provides some of the most pertinent concerns the Sol Systems team looks to address.

Procuring
Equipment

Procurement
can be a challenge because once a purchase order is issued, there is not much a
buyer can control. Despite needs and changes that arise on the developers’ end,
manufacturers almost always run on their own schedules. However, the buyer (in
most cases the contractor building the PV system) can ask several questions to
better understand timing for material delivery. There are two important
questions to ask of manufacturers.

Where is the
material coming from?
At what capacity
are plants running?

Responses
to these key questions will provide the buyer with a sense of expectations for
delivery. Material coming from overseas raises a red flag, as it may not be
allowed to enter the Unites States. If plants are only operational at a certain
percentage, the plant may be backlogged and material delays may be expected.
The manufacturer should provide expected timelines for deliveries and provide
feedback when delays are expected, but it is the responsibility of the buyer to
check in on these constantly to adjust plans and have alternatives if delays
are expected.

Utilities
and AHJs

COVID-19
has caused a great deal of uncertainty around Authorities Having Jurisdiction
(AHJs), the
county or local offices that review and approve designs/applications for
project permits, and utilities.

States
and localities have approached COVID-19 in varying forms: reduced hours,
reduced personnel, or closures. It is the contractor’s responsibility to know
if the local AHJ is operational. If so, at what capacity is the AHJ operating?
The AHJ’s availability will determine if permit applications will be reviewed
and approved in a timely manner, therefore maintaining the project schedule. As
projects near completion, AHJ inspections are required. Are inspectors willing
to go on site and if so, are there special considerations for in-person visits
like safety masks and gloves, requirement for reduced personnel on site,
restricted times and dates for visits? A project cannot close until the project
receives the final sign-off from the AHJ inspector. Contractors must
accommodate these needs.

Utility
considerations are similar. Utilities remain operational because they are
essential businesses, but COVID-19 may be affecting their solar operations. Are
they allowing teams to go on site for system interconnections, witness testing,
and installation of net metering (where applicable), or are restrictions in
place? An interconnection, especially at a facility that operates full time,
requires coordination between multiple parties. Understanding where the utility
stands on this topic will minimize delays. Lastly, how does an interconnection
or meter swap scope differ for activities inside buildings versus outside? It
is the contractor’s responsibility to ask these questions in advance and
prepare.

Hosts

Another
important consideration is the system host. Whether the PV system is a ground
mount, a canopy, or a rooftop, the contractor must understand the host’s
requirements. Is the host allowing construction at its site? If the host is
allowing construction, has that party issued special considerations or
protocols to take while on site? For example, they may require temperature
checks and sanitizing stations, limiting the number of construction employees
allowed on site, and limiting or restricting deliveries to the site. These
protocols impact construction activities and contractors must find ways to accommodate
these into the schedule. A limitation on the number of deliveries allowed on
site may require an adjustment in the sequence of activities. Close
communication with the host to coordinate these activities is essential to
project success.

Construction

Understanding
the external variables around construction is only a part of the planning
phase. Once the construction team is ready to go on site or resume its activities,
there are several considerations to take into account. Are there activities
that require close contact with others, for example module installation and
racking torqueing? If so, how should these activities be treated to ensure
everyone’s safety? The contractor should consider taking additional safety
precautions such as morning and evening safety check-ins, staggering lunches,
requiring the use of masks and gloves, requiring each employee to have and use
its own tools, and requiring each employee to clean machinery like lulls and
cranes after each use. Nothing should come before the safety of workers.

Commissioning
and Testing

The
last phase of construction is commissioning and testing. While some contractors
perform this in-house, others require third parties to perform testing. If so,
is the preferred testing company willing to have their employees travel to the
site? These same questions are applicable for manufacturer commissioning. Are
there company travel restrictions preventing or delaying personnel from
performing these activities? The contractor must consider how this impacts the
schedule and plan for alternatives, like hiring a certified third-party
commissioner who is available and willing to travel to the site.

In these uncertain times, solar energy contractors are responsible for ensuring the safety of their teams and all those who visit their project sites, while maintaining the agreed upon construction schedule and adhering to host, utility, and AHJ requirements. Clear communication, attention to detail, proper precautions, and keeping up with evolving health recommendations can ensure clean energy is put into the ground today safely and successfully.

ABOUT SOL SYSTEMS

Sol Systems is a leading national solar energy firm with an established reputation for integrity and reliability across its development, infrastructure and environmental commodity businesses.To date, Sol has developed and/or financed over 850 MW of solar projects valued at more than $1 billion for Fortune 100 companies, municipalities, counties, utilities, universities and schools. The company also actively shapes and trades in environmental commodity and electricity markets throughout the United States. The company was founded in 2008, is based in Washington D.C, and is led by its founder. Sol Systems works with its team, partners, and clients to create a more sustainable future we can all believe in. For more information: www.solsystems.com

5 Solar Technical Issues Avoided with Integrated Delivery and Engineering

Posted on February 7, 2020January 12, 2023 by Austin Ditz

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5 Solar Technical Issues Avoided with Integrated Delivery and Engineering

Technology | 07 Feb 2020

By Austin Ditz

As the solar energy market
grows, asset owners and investors must understand the technical risks that can
emerge during project construction and impact the long-term operation and performance
of their assets. However, owners and investors – who are rightly focused on
project finance -- are not always well positioned to see these risks. Instead,
they are reliant upon an independent engineer, hired to diligence the project
through a desktop review of engineering and project documents, and one or two
site visits during construction. Meanwhile, engineering, procurement, and
construction (EPC) contractors are focused on project construction and the
immediate warranty period thereafter, with less focus on long-term performance.
As a result, while many EPC contractors build high quality assets, the owner
can still be faced with the long-term operational challenges that may emerge
once the warranty period expires.

This gap can result in lost
production, as well as increased operational expenses like maintenance costs.
Solar asset owners should encourage collaboration between their project
delivery and asset management teams, establishing precedent for them to work
together during and after construction to ensure that solar assets are built to
and perform at the expected standard. Over the past several years, Sol’s
delivery and asset management teams have been compiling a list of common issues
that can impact long-term solar project performance. We reviewed the punch
lists from approximately 50 projects – a combination of rooftop, ground mount
and carport projects - and identified five of the most prevalent issues we
encounter:

Poor wire management: Every large PV system is home to thousands upon thousands of wires. Managing them correctly is of vital importance, yet many systems are prone to poor wiring. Photo 1a shows a site with various issues, including cables in tension, bend radius violations, and generally sloppy workmanship. Photo 1b shows cables and connectors on the surface of a roof. These poor practices can lead to safety and reliability issues such as premature insulation failures and electrical arcing and, in the worst case, fires. The contractor was required to redo the wire management in both instances. Proper wire management is indicative of high-quality workmanship; it is among the most visible aspects of a solar project, and among the most important practices a contractor can undertake.

Photos 1a, 1b

Improperly installed PV connectors: As with cables, every project has thousands of electrical connections which allow for the proper flow of generated power. As seen in photos 2a and 2b, connectors can often be an overlooked area of construction where mistakes are made. 1a shows a mated pair where the male and the female connectors are from different manufacturers, while 1b shows a connector where the nut on the left side is not torqued down properly, as seen by the three visible threads. Both issues can lead to problems like increased heat and resistance and electrical arcing issues, as well as potential UL listing violations. Manufacturer-specific installation instructions are key. These issues may not be noticed by untrained eyes but can have long-term impacts. If an asset owner is considering selling their PV plants, a savvy potential buyer may note these issues and demand remediation or a reduction in sale price.

A picture containing sky, indoor

Description automatically generated — Photos 2a, 2b

Improperly installed weather station components: Irradiance and temperature are key inputs to determining the performance of a solar project. These are measured with devices called pyranometers and back-of-module temperature sensors. Photo 3a shows a module temperature sensor affixed to the space in between the cells, rather than the best practice location in the center of the cell near the center of the module. Photo 3b shows an irradiance sensor installed right next to a shiny pole, which can cast a shadow or reflections at different times of the day. Both of these issues lead to poor data quality and can cause asset owners to come to misleading conclusions about project performance.

Civil construction and design issues: Ground mounted solar projects often require preparation work to prepare the site for long term use as the site for a solar project. Issues can arise from poor grading and poor erosion control practices. Grading, evening out topography on site, can aid in effective storm water draining from the site. In addition, if erosion is occurring onsite, it can impact the structural integrity of the racking system, expose buried cable, and prevent long term growth of grass or groundcover designed to stabilize the soil post construction.

Data Acquisition Systems (DAS) and Remote Monitoring: PV project owners and O&M service providers can monitor the performance of the sites and components through cloud-based software known as DAS. Though we’ve noted many common issues with data acquisitions system hardware, a thorough audit of the system in the online portal (as well as energy, power factors, etc.) can uncover a variety of problems, including mislabeled equipment, scaling issues with voltages and currents, missing data, sensor problems, and underperformance. Photo 5 shows a series of similarly sized string inverters which should be producing about the same energy. Proper setup of the system in these online portals is crucial for accurate data reporting.

Post Construction

As projects reach the testing
and commissioning phase, it is imperative that project managers engage their
asset management team to review commissioning reports, work with in-field
construction managers on punch lists, and review the capacity testing to ensure
performance. Collaborating on these post construction efforts helps inform both
project and construction manager efforts to close out projects while providing
the performance engineering team with valuable context around a plant’s early
operation. Such information can help reduce downtime in the early stages of
operation.

Beyond construction-specific
activities, the asset management and delivery teams should regularly
collaborate to the benefit of the company’s projects. At Sol, this
collaboration includes quarterly reporting on asset performance and regular
technical specifications updates. This reporting enables us to collect and
share feedback from different stages of the construction and operations process
to ensure the project’s success.

Through collaboration, a solar asset owner’s project managers and asset managers can identify potential issues early on and apply lessons learned to protect long term investments and returns. These efforts: reviewing prior punch lists to see trends, collaborating on commissioning activities, and meetings regularly to report on performance, combine the knowledge of project managers and asset managers, ultimately leading to a higher quality solar asset and a stronger return on solar project investments.

ABOUT
SOL SYSTEMS

Sol
Systems is a leading national solar energy firm with an established reputation
for integrity and reliability across its development, infrastructure and
environmental commodity businesses.To date, Sol has developed and/or
financed over 850 MW of solar projects valued at more than $1 billion for
Fortune 100 companies, municipalities, counties, utilities, universities and
schools. The company also actively shapes and trades in environmental commodity
and electricity markets throughout the United States. The company was founded
in 2008, is based in Washington D.C, and is led by its founder. Sol Systems
works with its team, partners, and clients to create a more sustainable future
we can all believe in. For more information: www.solsystems.com

Category: Technology