AXIS Talks: Solar Industry Surveying
Will Hitchcock Founder and CEO of Above Surveying
We caught up with Will to talk all about inspections for solar PV projects, microcracking and the importance of detailed data.
Will is the founder and CEO of Above Surveying, an aerial solar inspection and data analytics provider focusing on the utility-scale solar industry. Will’s journey into renewable energy started back in 2004 when he installed solar on his own home. In 2009 he co-founded the UK’s first solar cooperative which installed solar technology on community buildings.
He hopes that the solar industry will become a dominant part of the world’s energy mix and sees inspection and digitization services being a key part to making this happen.
AXIS TALKS: SOLAR INDUSTRY SURVEYING
"For the solar industry to thrive, regular, accurate and detailed inspections are paramount."
Tell us about Above Surveying and the services you offer?
We offer a range of aerial services from topographical surveying to thermography and ultra-high definition inspections. But it’s what we do with this data which is most important.
We’ve spent five years developing our digital platform to enable the fast and accurate processing of this data, as well as delivering valuable results to the end client. Our thermographic inspection service, for example, provides a full health report on 100% of the solar panels on an asset. Our services are used as part of the tech due diligence at engineering, procurement and construction (EPC) milestones, secondary market transactions and annual solar plant health reviews. Ultimately, we see the drone as a key tool in our offering, but our software platform is the backbone of our value proposition.
What is your biggest or most used product and why do you think that is?
Our main product from a revenue perspective is our aerial thermographic inspection service. Its opened up the possibilities of inspecting the health of every single solar panel on any size of solar farm. Five years ago, 100% coverage in this was simply impossible, but it’s our digital platform, SolarGain, that delivers the most long-term value.
At what stage of a project do developers normally contact you?
We offer a service which can support the entire lifecycle of the asset. From topographical mapping during planning and design, construction monitoring during the build, and then commissioning inspections at key milestones.
Most of our clients then use our inspection services throughout the operational life of the asset to get a full picture of its health and change over time.
What information do asset owners receive from you?
We publish all our reports through our cloud-based platform, SolarGain, which allows our data to be used in the way the client wants.
SolarGain is an interactive platform which delivers a true digital twin of the solar asset. Not only does it present the data in terms of longitude and latitude, but also the electrical context. This makes integration with other monitoring services such as SCADA possible.
How do you help companies with warranty enforcement?
We’ve helped many customers with successful warranty claims over the years. Either at the EPC milestone or direct to a solar module manufacturer, it’s vital that you have credible data to back up a robust warranty claim. Our thermographic inspection service conforms to the international standard for outdoor thermography of PV modules, which ensures its accuracy and credibility. We also back up our inspection data with consultative support when needed.
What is the difference in results between drone surveying and the manual testing of panels?
Manual thermography will always have a place in the industry, but it’s almost impossible from a logistical and economic perspective to use this approach to deliver 100% module inspections on multi MW solar farms. The drone approach enables consistency, accuracy and evidencable coverage.
Are you able to detect issues that were otherwise undetectable? If so, what?
Yes, the only other regular insight operators have access to is SCADA and Performance Ratio (PR) data. This data does not give you any detail on a solar module’s health. At best, string level SCADA will tell you if an entire string is underperforming, but this is difficult to identify in a sea of data coming from a typical monitoring platform. Using the PR value to understand performance really only shows a long term trend and will not help you optimize before significant yield is permanently lost.
Using aerial thermography, you can spot issues at a cellular level and identify degenerative and systemic issues with the module long before you would otherwise be able to. Problems such as Potential Induced Degradation (an issue that affects the power produced by a module), which can be catastrophic for a solar farm, can only really be identified in its earliest form by a drone inspection.
Microcracking is an issue that has been getting more awareness recently. What usually leads to microcracking?
Microcracking is an interesting one as it typically only gets identified after two or three years of operation. Microcracks are often introduced by poor transportation and/or heavy handling of the solar modules. Often, microcracks don’t necessarily cause power losses until a few years down the line.
They sometimes surface themselves as ‘snail trails’, visible to the naked eye. With continuous cycling of thermal and physical stresses over time, these cracks will propagate into ones that do cause power losses.
What can be done to mitigate microcracking?
That’s quite simple: handle solar modules carefully, they are fragile. Never walk on them!
Unfortunately, nothing can be done to repair a cracked cell. The best approach, if you have them, is regular inspections to monitor how quickly they are propagating and impacting module performance. This data can then underpin your strategy for replacement, supplying spares and possible repowering in the future.
How much microcracking can you have before it becomes a problem? Is it the same for every module or different depending on make and model?
For scenarios pre-EPC warranty, the levels of crack acceptance really need to be agreed before construction to ensure you have a sensible tolerance to work to. Some microcracks are introduced at the factory, so agreeing to a practical testing protocol from factory to shipping to mounting on site is important.
For a solar plant post-EPC warranty, if you become aware of microcracks, it all depends on how much loss you are prepared to accept over time and whether the cracks could lead to a safety issue in the future, especially on roof installs.
What do you see as the future for inspection surveys?
I see the drone as a staple tool of the solar industry with fully autonomous drones based at large, remotely located assets and fulfilling targeted missions; flying intelligently and processing data in real-time.
Do you see other trends emerging in solar PV surveys?
As some of the early assets start to age, we are now seeing degenerative issues that do not initially show themselves in thermography. Failure modes such as delamination, snail trails and corrosion, indicate future problems and losses and can be recorded using ultra-high-resolution visual cameras on drones. We have recently launched a new inspection and software solution to deliver this type of monitoring. Monitoring down to the module-level is the direction of travel for the industry.
This material is for general information, education and discussion purposes only. Statements contained herein are not an endorsement of any particular product or service and are not professional or legal advice of AXIS or its affiliates. AXIS makes no representations as to the accuracy or completeness of the information and is under no obligation to update or revise the information as a result of new information, research or future events. AXIS assumes no liability by reason of the information within this material.
