AR panel placement verification attracting attention at the Solar Expo: drastic reduction in installation errors and improved accuracy

At this year’s solar power-related exhibition (hereafter “the Solar Expo”), a technology for verifying the placement of solar panels on-site using AR (augmented reality) drew major attention. While the solar power market expands, construction sites face many visible challenges such as panel placement mistakes, discrepancies with design drawings, labor shortages, and increased costs from rework. As a solution to these industry headaches, an approach using AR to project and check installation positions on-site was proposed as an effective remedy. This article explains in detail the issues at solar power installation sites and AR as a solution, concrete use cases and the benefits obtained, and the DX (digital transformation) of workflows from design through construction and inspection. Finally, it touches on simple surveying that leverages the latest technology “LRTK,” which supports the high accuracy of AR placement, and discusses the prospects this brings to the solar power industry.

Current state of the solar power market and challenges at construction sites

With the tailwind of renewable energy promotion, the adoption of solar power systems is accelerating across Japan. As installation projects increase from residential roofs to mega-solar sites, the following issues have been pointed out on job sites:

• Panel placement mistakes: Slight deviations in panel mounting positions or angles can cause overall misalignment of the system or interference with adjacent structures. For example, if the support post position on a racking system shifts by just a few cm (a few in), the hole positions on the mounting brackets may no longer line up or wiring may not reach. As a result, additional on-site work or adjustments become necessary, causing quality degradation and reduced power generation efficiency (not receiving the expected sunlight, inability to secure maintenance walkways, etc.).

• Design errors and inconsistencies with drawings: If initial site surveys or designs are incomplete, discrepancies such as “the actual slope was steeper than designed” or “obstacle locations differed from the drawings” can surface during construction. Oversights during the design stage can lead to situations where panels don’t fit the planned spots or are placed in shaded areas once construction begins. In such cases, redesigns or sudden plan changes at the site occur, causing overall project delays and increased costs.

• Labor shortages: Despite the rapid spread of solar power, there is a shortage of skilled installers and surveyors for fieldwork. Mega-solar construction across vast sites ideally requires many surveying and construction staff, but chronic manpower shortages force small teams to handle countless panel installations. Aging veteran technicians and a lack of younger workers compound the problem, increasing both the burden on each individual and the risk of human error.

• Rising rework costs: The mistakes and delays caused by the above issues often lead to rework. Removing and repositioning already-installed panels or piles, rebuilding racking systems, and performing additional wiring or reinforcement work entail significant time loss and expenses. If schedule delays push back inspections and handovers, trust with clients can be jeopardized. The environmental impact from increased material waste and heavy machinery operation is also non-negligible, so completing work accurately the first time is required.

To address these challenges, the industry expects construction DX through digital technologies. Among these, on-site verification of panel placement using AR has attracted attention as a trump card to support construction sites in both accuracy control and efficiency improvement.

Overview of AR technology and its application to solar panel installation

AR (augmented reality) is a technology that overlays digital information onto real-world scenery. By viewing a site through a smartphone or tablet camera, virtual objects and lines appear on the screen as if they exist in front of you. Applied to solar panel installation, this technology enables projection of panel layouts and reference lines from the design drawings directly onto the actual site.

For example, even when nothing is yet installed on a roof or land, an AR app can display the designed panel layout on the screen, visually indicating installation positions and angles. Because it appears as if virtual panels are floating in place on-site, installers no longer need to mentally interpret drawings and can proceed while checking the completed look at the scene. Compared to the conventional method of measuring with paper drawings and a tape measure, following on-screen guides is intuitive. The clarity of having guides directly in the physical space allows even non-experts to position equipment accurately in terms of location and orientation, significantly reducing human error.

Moreover, recent AR construction-support systems combine high-precision positioning technologies to achieve precise AR displays with no deviation down to the centimeter level (half-inch accuracy). Simple AR functions used to suffer from drifting—move the device slightly and the on-screen display would gradually shift. But by constantly correcting device position and attitude with GNSS (satellite positioning) and inertial sensors, virtual objects appear firmly fixed at their intended real-world positions even while walking around. This is revolutionary for construction applications of AR, and demos at the exhibition amazed visitors who said, “The display really doesn’t drift!” The improved AR accuracy, enabling seamless overlap of real space and digital design, has made AR use at solar panel installation sites suddenly practical.

AR use cases: from residential roofs to mega-solar sites

AR panel placement verification is being used across a variety of site sizes and types. Representative use cases by scene are listed below.

• Detached house roofs: Even for complex roof shapes, AR can project and confirm panel layouts in advance. You can check on-site whether panels fit while avoiding obstacles such as chimneys and vents, and whether slopes and orientations match the design, adjusting layouts on the spot as needed. Showing the completed image to homeowners on-site prevents misunderstandings like “it looked different after installation” and helps build prior agreement.

• Ground-mounted solar farms (open-field installations): AR shines in mega-solar construction, where many panels are laid out over vast land. By displaying designed panel rows and foundation pile positions on the ground with AR while workers walk and mark, a single worker can perform a large amount of stake-out in a short time. Tasks that used to require a surveying team to set each pile position can be reduced to simply marking according to AR guides, substantially reducing manpower and time. It is effective in preventing pile-driving mistakes across wide areas, allowing thousands of piles to be driven while maintaining overall alignment.

• Parking lot carports: For carports with panels over parking lots, design must consider vehicle layout and shadow movement. AR can project virtual panel roofs and column positions over parking spaces, allowing intuitive checks of vehicle access and solar exposure impacts. You can confirm on-site whether column positions will obstruct cars or whether roof coverage is sufficient, preventing post-installation corrections due to mismatched expectations. Because the surrounding environment can also be checked on the spot, AR is useful for explaining visual harmony and landscape considerations.

• Large factory and warehouse rooftops: Even when densely covering a wide, flat rooftop with panels, AR can display guideline markings according to the planned layout. Workers can walk the rooftop and mark along grid lines and panel frames shown on-screen to achieve perfectly aligned panel placement even across vast roofs. Since obstacles like outdoor AC units and exhaust ducts are also shown in AR, it’s immediately clear whether placement avoids such equipment. Traditionally, laying out positions on a large roof required effort with tape measures and chalk, but AR enables quick and accurate layout checking and marking.

As above, AR panel placement verification acts as an effective pre-construction confirmation and guidance tool across a wide range of sites from residential to industrial. Its strength—reproducing the design drawings on-site—has begun to be leveraged in diverse applications.

Benefits gained by improving pre-installation verification accuracy

When AR dramatically improves pre-installation verification accuracy, the benefits to the field are immense. The main advantages are summarized below.

• Prevention of construction mistakes: By following clear visual AR guides, measurement errors and positional misunderstandings can be prevented. Digital assistance covers parts previously dependent on human interpretation or manual measurement, drastically reducing human errors like “drilling hole in the wrong place due to misreading” or “missing a marking.” As a result, the likelihood of finishing correctly on the first installation increases, greatly reducing rework. From the perspectives of quality trouble prevention and safety assurance, this is a step toward zero installation mistakes.

• Consensus-building with customers and stakeholders: Being able to share the completed image in advance with AR is highly effective for communication with homeowners, local residents, and clients. Showing homeowners on-site “this is how it will be installed” allows them to concretely imagine the outcome and feel reassured. For large projects, using AR in community briefings to show visual impacts on the landscape makes it easier to gain understanding. Because all stakeholders can view the same completed image and align their recognition, consensus-building becomes smoother and you can avoid later complaints like “we weren’t told that” or “it’s different from what we expected.”

• Improved construction speed and efficiency: AR reduces the time required for layout marking and inspection, speeding up the overall construction timeline. Even on large sites where surveying and layout used to take days, AR navigation can complete the work quickly and allow mounting work to start sooner. If rework decreases due to mistake prevention, lead times shorten. Also, because on-site communication can take place while viewing AR images, time spent pointing at drawings and confirming dimensions is reduced, improving team coordination. Efficiency improvements directly compensate for labor shortages, enabling smaller crews to work at a pace equal to or higher than before.

In addition, constructing exactly to the design contributes to maximizing power generation performance and equipment lifespan. Keeping panel orientation and spacing optimal yields the simulated generation output, and arrangements that facilitate maintenance help prevent future troubles. AR pre-verification not only improves immediate site efficiency but also enhances long-term project results.

Embedding DX in the workflow from design to construction and inspection

AR panel placement verification is not merely a site gadget but realizes a new workflow that consistently uses digital data from design through construction to post-completion inspection. It connects the traditionally fragmented phases seamlessly and promotes construction DX; the flow is outlined below.

• Design phase – In the initial planning and design stage, optimal layouts are considered using detailed site data and simulation. If digital design data created with BIM software or PV simulation tools can be projected on-site with AR as-is, desk plans and actual site conditions can be validated in advance. For example, designers can walk a candidate site with a tablet and display virtual panels in AR to identify issues overlooked on drawings alone, such as “this tree may cast a shadow in the afternoon.” Immediate on-site feedback can be reflected in the design, allowing creation of highly refined plans on paper. These digitally optimized layouts are then smoothly handed off to the construction phase.

• Construction phase – During construction, the completed design data is loaded into an AR-compatible app for on-site use. Field staff use smartphones or tablets and proceed while viewing digital design drawings overlaid on the real site. The typical procedure starts with aligning the device at a reference point (calibration), after which workers install components following on-screen lines and markers. There are systems that guide workers to pile-driving points with navigation displays like “north by ○○ cm (○○ in), east by ○○ cm (○○ in),” eliminating the need to repeatedly check paper drawings and measure dimensions. By checking positional correctness in AR at key points as work progresses, deviations can be corrected on the spot. Digital data-based construction navigation enables high-precision work without relying on craftsmen’s intuition or experience.

• Inspection and maintenance phase – AR is also useful for post-construction inspections and periodic maintenance. Inspectors can hold up a device on-site and compare the design drawings (or BIM model) with the completed installation in AR. This allows visual identification of deviations on the order of a few cm (a few in) that are hard to notice with the naked eye, enabling inspections that are more efficient and accurate than before. For example, if you wonder “is only this row slightly off position?”, comparing the actual with the ideal location in AR makes it immediately clear. If inconsistencies are found, corrective actions can be taken immediately, and photos taken with AR overlays can be saved as digital construction records. Such records are useful for future maintenance planning and root-cause analysis in case of problems. Showing AR during administrative inspections can also facilitate approvals. In this way, embedding AR in the workflow enables ideal DX where data is used consistently from design through construction and inspection.

Ease of use with smartphones and tablets

A major feature of AR construction support is that it can be used with readily available smartphones and tablets. There is no need for expensive dedicated equipment or special headsets—installing an app on mobile devices that field staff already use lets you begin AR-based placement verification. Intuitive user interfaces are designed so that anyone can operate them; untrained workers can master the app after a short explanation.

For example, at one exhibition demo a veteran construction manager could identify pile positions simply by walking along AR lines displayed on a smartphone and said it felt “just like using a car navigation system to reach pile-driving points.” Young technicians also commented that it was “game-like to align positions on-site,” showing the interface is accessible regardless of age or experience.

The smartphone/tablet base also offers mobility and low cost. Previously, carrying tripod-mounted surveying instruments or large drawings made moving around roofs or hilly sites physically taxing. In contrast, an AR system that runs on a smartphone and small accessories allows a worker to climb onto a roof with one hand and verify placements on the spot. Equipment is compact and powered by internal batteries, so deployment is quick and location-flexible. From a cost perspective, using existing devices is cheaper than acquiring dedicated hardware, reducing setup burdens. No site-by-site rental or elaborate setup is required, so AR can be flexibly introduced from small sites to simultaneous multi-site construction.

In short, AR construction support using smartphones and tablets offers the appeal of “anyone, anywhere, immediately” usability. This lowers the psychological barrier to adopting new technology and is an important factor promoting industry-wide uptake.

Improved accuracy through integration with BIM and CAD data

Behind AR panel placement verification is smooth integration with design data. Modern AR applications can directly import and overlay digital design data such as drawings and 3D models on-site. For example, CAD drawing data (DWG/DXF, etc.) or BIM models created by designers can be loaded into the app for AR display. This allows precise design-stage plans to be reproduced on-site without any simplification.

Previously, preparing on-site layout drawings or entering coordinate lists into surveying instruments was necessary, but AR that supports CAD/BIM integration eliminates those tasks. Once design data is available, AR automatically displays it at the correct positions in the field, ensuring that office and site always share the same information. If there is a design change, updating the data immediately reflects in the on-site AR display, allowing construction to proceed according to the latest plan without transmission errors.

Using BIM models also enables checking not only panel placement but associated structures, cable routes, and equipment in AR. For example, displaying racking structure models or cable routing from BIM data allows checking of interfacing for ancillary works at the same time as panel installation. Thus, AR/BIM/CAD integration directly links design accuracy with construction accuracy and plays a key role in closing the gap between drawings and the field.

Reception at the Solar Expo and exhibitors’ initiatives

At the Solar Expo, AR construction support technology drew strong attention from attendees. Many installers, designers, and municipal officials visited booths and watched smartphone-based AR demos intently. At one booth, with the catchphrase “Your smartphone becomes a cm-class surveying instrument!” a live demo used a small device attached to a smartphone to perform AR guidance. Staff mirrored the phone screen to a large display and showed virtual lines and points on the exhibition floor; observers were astonished to see CG guides remain perfectly fixed even though there was nothing on the real floor.

Visitor questions commonly included “Can a smartphone really perform such precise layout?” and “How reliable is AR display accuracy?” Staff demonstrated by walking around the venue that “just launching the dedicated app and holding up the device enables centimeter-level measurement immediately,” and explained thoroughly that correction signals use Japan’s quasi-zenith satellite system Michibiki (CLAS), maintaining high accuracy even in mountainous areas outside of coverage. Watching the demo where the AR display hardly drifted despite the operator moving around, attendees leaned in to peer at the screen. Comments like “I’ve never seen AR that doesn’t drift” and “This looks ready for immediate field use” were heard from a wide range of experience levels, from novices to veterans, indicating a strong impact.

The exhibition also featured seminars on themes like digital construction management and smart surveying that included AR technology. Case studies of AR use in actual construction sites were presented, and audiences listened attentively. Practical questions such as “What are the introduction costs?” and “How do we import existing design data?” were frequently asked, showing high industry interest. Exhibitors used booth consultations and hands-on experiences to highlight the strengths of their AR solutions, and the whole Solar Expo felt energized by interest in cutting-edge construction support technologies.

Effects realized after AR introduction: use case examples

Companies that have actually introduced AR panel placement verification have already reported remarkable effects. One solar construction company reported that after introduction, panel installation mistakes decreased by about 80%, and the time required to explain and obtain approval of layouts from clients was halved. Because AR allowed accurate sharing of the completed image in advance, on-site rework was drastically reduced and stakeholder consensus was reached more quickly, contributing significantly to overall schedule shortening and cost reduction. One site supervisor commented, “Compared to the days when we showed drawings and explained verbally, conveying things visually speeds everything up,” underscoring gains in communication efficiency.

In another case, a new staff member following AR guide lines completed layout marking in a short time with accuracy comparable to that of experienced staff. This helped standardize processes that had depended on veterans and increased flexibility in personnel allocation. These use cases show that AR technology is not merely a trendy gadget but a practical tool that dramatically improves field productivity and quality. Concrete results in reduced installation errors and smoother communication, backed by numbers, suggest many more companies will adopt AR going forward.

Lightweight surveying technology LRTK supporting AR placement accuracy

Behind the high accuracy of AR panel placement verification is the latest lightweight surveying technology. A representative solution is LRTK, which uses a small device attached to a smartphone and a dedicated app to enable anyone to achieve centimeter-level positioning easily. LRTK adopts the RTK-GNSS (real-time kinematic satellite positioning) method and leverages correction information such as the centimeter-class positioning augmentation service (CLAS) provided by Japan’s Michibiki quasi-zenith satellite system, enabling nationwide outdoor positioning accuracy of about 1–2 cm (0.4–0.8 in).

Usage is simple: attach the device to a smartphone and start the app. High-precision positioning begins in just a few tens of seconds, and then pointing the device at a point immediately records its exact coordinate value. No complex manual calculations or communication settings are required, and collected point data is automatically shared to the cloud, eliminating the need to bring measured values back to the office for re-entry. With the advent of LRTK, baseline-setting tasks that previously required two-person teams and a total station can now be completed by one person walking with a smartphone.

This high-precision smartphone positioning plays a major role in AR placement verification. To make AR displays align perfectly with real locations, the device’s current position must be accurately known; LRTK makes that possible. In other words, “AR that does not drift” is achievable because of LRTK. On sites that introduced LRTK, users reported they could trust that AR lines wouldn’t shift, allowing them to work with confidence. This is thanks to LRTK continuously correcting the smartphone’s position to centimeter-level accuracy and keeping AR objects properly fixed in real space.

Furthermore, LRTK is useful in many other field scenarios beyond AR placement verification. Using built-in LiDAR or cameras, it can perform 3D point-cloud scans of a site, and overlay acquired point-cloud data with design models to check as-built conditions and quantities, functioning as an all-purpose surveying, measurement, and recording tool. Since all of this can be done with a single smartphone, it has been called a “pocket-sized all-purpose surveying instrument.” Its small, lightweight nature makes it easy to carry on-site and a reliable companion for construction managers handling multiple sites.

Thus, advanced positioning technologies like LRTK are the unseen pillars supporting AR construction assistance. Because sophisticated technologies operate behind the scenes, users can enjoy a comfortable, high-accuracy AR experience without conscious effort. As positioning devices and AR apps become more refined, solar power construction sites will evolve toward a level of “no failures, no rework.” The AR panel placement verification technology that was a hot topic at the Solar Expo, together with such underpinning technologies, is sure to powerfully drive DX in the renewable energy industry.