Drone-in-a-Box tech is likely to be standard on large-scale utility (100MW+) solar facilities in the next 1-2 years
Operations and maintenance of utility-scale solar farms is a balancing act of safely maximizing system performance while reducing OPEX (Operating Expenses). Safety is non-negotiable, so the focus is finding a balance between system performance and OPEX. Historically, choosing one can negatively impact the other. It is rare that an innovation comes along that checks all boxes (pun intended), but we are on the verge of exactly that with Drone-in-a-Box.
What is Drone-in-a-Box, exactly, and why is it important to solar operations?
The Drone-in-a-Box (DIAB) is the latest evolution of autonomous unmanned aerial vehicle (UAV) technology utilizing drones that can be remotely deployed via self-contained “boxes.” These boxes are weather-resistant enclosures that contain the necessary equipment to communicate with the UAV as well as recharge.
Traditionally, a pilot with a ground-based controller is required to be present to operate the UAV. DIAB systems can be remotely operated or deployed autonomously and carry out on-demand, or pre-mapped, missions. Once the missions are completed, the DIAB returns to its box to be protected from the elements as well as recharge and/or upload information.
This is important to utility-scale (in this case 100MW+) systems because the technology can safely maximize system performance while reducing OPEX in many areas. The primary use of drones equipped with IR cameras in utility solar is to scan for thermal anomalies annually. Armed with Raptor Solar reporting and software, operators can then remedy high-priority findings. Many of the highest priority findings impact system performance, but if sites are only inspected annually, months may pass before losses are identified. The integration of a DIAB will allow owners and operators to roll out more frequent inspections and save valuable power production.
Looking at a few scenarios outlined in the chart below, we are able to break down and visualize the cost differences between traditional data capture (operator + drone) and DIAB. For all examples, we assume a 100MW system and adjust the scan frequency with traditional methods vs DIAB. Most notably, the red line shows purchasing a new DIAB every 10 years and performing annual maintenance on the device is aligned with today’s cost of a single annual scan. This means that DIAB will unlock the full suite of services and labor-saving activities listed below for the same investment most facilities are modeled with today. It is clear that DIAB has the potential to impart significant savings over the life of a solar asset.
Key Benefits of Drone-in-a-Box to Utility-Scale Solar
The true power of DIAB to operators and asset owners has yet to be made clear. However, here are some of the top ways it can be utilized.
Quarterly IR Inspections
Traditionally, aerial IR inspections are performed annually or bi-annually due to OPEX budget constraints as outlined in Figure 1. DIAB unlocks the ability to increase inspection frequency to quarterly for nearly the same cost as a single annual scan. This allows asset owners and operators to fully understand the DC health of the system throughout the year and plan mitigation while increasing system performance. The industry has also seen an increase in extreme weather which can be damaging to solar assets. Increased scan frequency and the ability to have scans on-demand will allow for extreme weather damage to be assessed immediately following an event.
Substation and Overhead Line Inspections
Since substation IR inspections are currently only performed annually, it is possible for critical components to overheat and fail over time. Increasing the inspection frequency (to weekly, monthly, or quarterly) of these key components and terminations will allow operators to identify areas of concern much earlier. Many times a loose bolt or stressed termination can cause catastrophic failure if left uncorrected. Identifying these problem spots sooner with DIAB can potentially save hundreds of thousands in equipment and performance losses.
Overhead lines within the array are becoming more common as systems get larger and sprawl on more dispersed parcels. Inspecting these lines currently requires the dispatch of specialized technicians and equipment. Frayed or overheating connections on overhead lines can be very costly to repair and can potentially force whole blocks of arrays offline. Utilizing DIAB will reduce this expense and increase inspection frequency.
When a block, inverter, or combiner is suspected of underperformance (or offline), DIAB can quickly be deployed to gather IR and RGB images that are critical for Control Room engineers to understand the outage. This potentially prevents a truck roll and allows the full diagnosis remotely. At present, remote operators and field technicians need to coordinate reactive inspections and the cost of these inspections can be higher than annual inspections due to mobilization.
Monitor Vegetation, Civil, and Fences
Vegetation maintenance on utility-scale solar facilities is a significant part of the annual project budget and in some cases can be more than half. Timing your vegetation activities (spraying and mowing) is a key component to getting the most out of your spending. Implementing a weekly vegetation inspection by DIAB will allow you to time these more appropriately. Monitoring overgrown vegetation will also prevent module shading and ensure better system performance.
Roads, fences, and inverter pads are part of routine operator maintenance. Most of these inspections do not lead to improved system performance and can take time away from other activities that can. With DIAB you will be able to inspect roads and inverter pads for erosion and examine fences for damage from the control center. This frees up valuable time for your site team to make high-priority repairs.
Security and Site Access
Site security on facilities as large as thousands of acres can create technology, manpower, and cost constraints. In many cases, this means large sections of the array will have no security oversight and rely on perimeter inspections. With a DIAB, operators will be able to schedule regular perimeter inspections as well as respond in real time to security concerns.
Another benefit will be monitoring gate access and having visual confirmation that the permitted visitors are the only ones accessing the site. On NERC (North American Electrical Reliability Corporation) facilities, this access logging is a requirement of CIP (Critical Infrastructure Protection), and the DIAB images can act as redundancy to sign-in sheets.
Weekly Tracker Verification
Utility-scale tracker systems are equipped with remote system monitoring and an array of TCUs (Tracker Controller Units) that allow control centers and plant managers to identify misalignment and offline tracker tables. As with any system, this can be flawed, and device connectivity can make it difficult to discern if the equipment is offline vs not communicating. A weekly high-altitude overview flight with a DIAB will allow for monitoring redundancy and verification of tracker functionality. Identifying and correcting misaligned or offline trackers will lead to better system performance.
How to Prepare for the Emergence of Drone-in-a-Box
Implementing routine aerial IR inspections today is a major step to normalizing these activities on your site. This coupled with a robust digital twin in our Raptor Solar application will lay the mapping groundwork for rolling out DIAB in the near future. Raptor Maps is working with hardware integrators to stay at the forefront of the DIAB roll-out as well as uncovering ways our application can supercharge this technology.
To learn more about Raptor Maps' Asset Management Platform or how we're enabling DIAB for solar, contact us here.