The world’s population is undeniably becoming increasingly environmentally conscious. Customers and citizens are expressing their heightened awareness by voting with both their ballots and pocketbooks for greater waste reduction and cleaner energy sources. Scientists argue that fossil-fuel supplies are diminishing, more and more private and public sector organizations are turning to renewable energy sources such as wind and solar. Impressively, solar energy is expected to comprise 21 percent of total electrical power production in the U.S. within 30 years.
Experts predict an 81-percent growth rate of solar adoption in the European Union over the next few years as well. According to a recent webinar by DJI, Germany, Spain, France, Netherlands and Italy will soon generate more than 75 percent of all European photovoltaic energy
In addition to the growth of gargantuan solar farms, homeowners are looking to solar panels to reduce energy costs. According to the Solar Energy Industry Association: “residential installations helped the U.S. solar market grow 45 percent year-over-year [as of the third quarter of 2019] and contributed to 15 states having their best quarter ever for residential solar.” This year, California rolls out the 2020 Solar Mandate, requiring all new homes to include solar panels (with some exceptions).
And while solar farms and on-site installations continue to grow, builders face new and often dangerous challenges when it comes to maintenance and inspection. Drone technology has risen to that challenge as individual pilots and companies ramp up customized inspection services for multiple-panel facilities and individual building sites.
How do solar panels work?
Before we dive into drone inspection topics, it’s important to understand how solar energy works. First, you have the sun – the huge, hot yellow…okay, you know that part. Anyway…
Solar panels are part of a photovoltaic system. Each panel comprises several cells which absorb sunlight (photons). The photons are then converted to electrons by baked-in semiconductors. Electrons create a current measured in voltage which then powers the building or home. For a deeper dive into solar energy, check out HowStuffWorks.
Solar companies have historically deployed workers to climb roofs to perform pre-inspections as well as post-installation maintenance. In addition to falls, workers also face electrical hazards.
According to an OSHA report:
“Workers in the solar energy industry are potentially exposed to a variety of serious hazards, such as arc flashes (which include arc flash burn and blast hazards), electric shock, falls, and thermal burn hazards that can cause injury and death.”
Each year, around 100-150 solar technicians die from falls. Clearly, drones offer a safer solution to solar-panel inspection.
Drone flights equip workers to survey roofs before panel installation, allowing planners to take structure, depth and other factors into consideration via digital maps. Following installation, drones can gather thermal and 3D imagery and data to locate trouble spots – cell failure, solder corruption, connection failure and solar-cell degradation. Technicians can analyze and share aerial data via online portals or device apps.
Advantages of Drone Solar Inspection
Data quality
Drone inspections provide high quality data when compared to manual analysis. Equipped with the proper sensor array, a UAV can automatically fly over roofs gathering uniform data in less than 15 minutes. The data can then be transmitted to specialty software that produces actionable reports.
Cost/Time
Not only do drone inspections require fewer workers (and thus fewer man-hours) but drones collect data more than 50 times faster than manual inspections. According to drone-inspection firm Measure: “Our experience has exceeded 1.5 gigawatts of installed solar. On a per-megawatt basis, cost savings due to efficiency gains ranged from $1,074 to $1,717 per megawatt for an average of a $1,254 per-megawatt cost savings.”
In addition to being more accurate than traditional methods, solar-inspection drones take much less time per mission. As a Measure spokesperson noted about a specific mission: “The results from the manual inspection mirrored the results from the drone data with 99 percent accuracy, but the manual inspection took two days compared to two hours with the drone.”
Methods
Because drones are a flexible technology in terms of sensor payload, inspectors can deploy thermal/infrared cameras, RGB cameras, LIDAR and other precision detectors.
Thermal Imagery
“Drones featuring thermal imaging payloads allow operators to perform a full solar farm operation in a matter of hours, compared to days using manual methods,” Eduardo Rodriguez, Enterprise Product Manager for DJI Europe, said in a recent webinar. “They increase data quantity and quality and reduce costs.”
Some of the top products used in thermal missions include:
DJI Zenmuse XT2 Thermal Camera – provides the 640×480 thermal resolution required to complete an effective solar-panel inspection; integrates a high-resolution FLIR thermal sensor and a 4K visual camera; features Temp Alarm, Heat Track, FLIR MSX, Isotherms and Color Palette choices.
FLIR Vue Pro – a relatively affordable heat-vision camera with 4K color imager; includes on-board recording and flight controller integration with built-in data gathering functionality; meta data can be embedded via GPS, IMU, magnetometer and barometer.
RGB Cameras
While thermal imagery can provide quantitative analysis (i.e. measurable metrics with regard to temperature, etc.), a proper inspection requires vivid imagery from a hi-res camera – qualitative analysis. An expert on solar panel maintenance can often diagnose a problem by viewing video of the site.
As Rodriguez notes:
“With the use of drones, apart from increased efficiency and reduced costs, we can capture both thermal and RGB data and this is really, really relevant. By carrying out only thermal inspections, this could potentially lead to a false positive, which means we could misidentify non-electrical issues like soiling, shading or animal nesting, and you could be misled to thinking that these are electrical problems when they actually are not.”
For example, DJI’s Zenmuse Z30 Digital Zoom sports an optical zoom of 30x and digital zoom of up to 6x for optimal data/image capture.
LiDAR
LiDAR (Light Detection and Ranging) technology produces and measures rapid laser pulses. It can measure the distance from sensor to the target area by calculating the time between the release of the pulse to time the pulse is reflected back and received.
Using LiDAR, a solar-panel consumer can determine how much sunlight their roof receives which helps determine the best placement for a solar array. LiDAR can model landscapes, calculate heights and roof slopes and terrain to produce a 3D point cloud.
Popular culture typically treats business and the environment as opposing forces, but his isn’t necessarily true in reality. The technology-enabled solar energy revolution may just be getting started and the explosive growth of the drone services industry in recent years, along with new innovations rolling out at a breakneck pace, is creating a win-win situation for both businesses and environmental causes alike.
Learn More
If you want to learn more about the benefits of thermal drone imagery for the energy industry, or you’re interested in obtaining footage of your project please contact us at Dronegenuity. We offer professional drone services, performed by an FAA licensed drone operator for a variety of customers of all sizes. All of the work that we do is completely customized and we make the process simple and convenient.
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