Georgia has a lot of utility scale solar now, most of it on land that was timber or farmland a few years ago, and most of it a long way from anywhere. These sites share a problem: they are large, they are monotonous, and the failures that cost money are invisible from the ground.

Why thermal is the right tool

A photovoltaic module that is not producing gets warm. Current that cannot leave as electricity leaves as heat, so almost every failure mode has a thermal signature, and each signature has a shape.

A single hot cell usually means physical damage or a crack. A hot diode, showing as a warm third of a module, means a bypass diode has failed and a substring is not contributing. A whole module warmer than its neighbours suggests a connection problem. An entire string dark against the rest points at combiner or wiring issues upstream of the panels.

Walking a site with a handheld camera finds these one at a time. A flight covers a hundred acres in a morning and produces a map of every anomaly, located precisely enough that a technician drives straight to it.

What a survey needs to be valid

Conditions matter more here than in almost any other inspection work. Irradiance needs to be high, ideally above six hundred watts per square metre, because a module has to be working hard before a fault shows as heat. That means clear sky, middle of the day, which is the opposite of when we fly most other jobs.

Wind steals heat from module surfaces and flattens the differences you are looking for. The camera has to be radiometric, so every pixel carries a temperature rather than a colour. And the flight has to be high enough to be efficient and low enough that a single cell is resolved across enough pixels to be trustworthy.

A survey flown at the wrong time of day is not a cheaper survey. It is a folder of images with nothing in them.

The visual pass matters too

Thermal finds electrical faults. A visual pass finds everything else, and on Georgia sites that list is long: vegetation growing into rows and shading modules, erosion and washouts after summer storms, tracker misalignment, damaged fencing, standing water, and access roads that have quietly become impassable.

Vegetation is the recurring one. Growth here between April and September is aggressive, and a row that was clear in spring can be partially shaded by July, which shows up as a production loss that nobody has connected to a cause.

The line of sight problem

Large sites are exactly where the visual line of sight rule hurts most. A five hundred acre site cannot be flown from one position, so the crew leapfrogs, and the drive between positions costs more than the flying.

This is one of the clearest cases for the rule change we discussed in Part 108, and until that lands the honest quote for a large site includes the repositioning time.

What we deliver

An anomaly report keyed to the site layout, with each finding located, classified by type, and severity ranked so the operations team can triage. A thermal orthomosaic of the whole site for context. Visual imagery of anything worth seeing in daylight. And, where a site is surveyed repeatedly, a comparison against the previous survey, which is what turns an inspection into a maintenance programme.

The thermal fundamentals are the same ones we covered in thermal roof inspection, applied to a very different surface.

If you operate solar or other large infrastructure in Georgia, tell us the acreage and the layout and we will scope a survey against it.