Question 1

What Is Drone Cleaning?

Accepted Answer

Drone cleaning uses a purpose-built cleaning drone to reach exterior surfaces or solar installations from the air while the pilot and flight team operate from the ground. The Big Great system is designed for windows, glass, facades, roofs and solar panels, with cleaning configuration selected for the actual surface and site.

Question 2

Is Drone Cleaning Suitable for Every Building?

Accepted Answer

No. Suitability depends on building geometry, surface, recesses, balconies, overhangs, obstructions, ground area, VLOS and site activity. Some areas may suit drone cleaning while others may be better served by rope access, MEWP or another access method.

Question 3

How High Can a Cleaning Drone Operate?

Accepted Answer

Operational height is not determined by the drone’s maximum capability alone. It must follow the applicable CAAT permission, airspace and operating conditions. The current CAAT over-25 kg checklist states a standard operating limit of 300 ft, approximately 90 m, unless the relevant permission provides otherwise.

Question 4

Does Drone Cleaning Replace Rope Access?

Accepted Answer

Not for every scope. Drone cleaning can suit aerial cleaning tasks, while rope access remains valuable when the work requires direct surface contact, detailed cleaning, inspection, maintenance or repair.

Question 5

Can Drone Cleaning Operate in Any Weather?

Accepted Answer

No. Weather is part of the go/no-go assessment before operation, including wind, visibility, rain and aircraft limitations.

Question 6

Does Drone Cleaning Require CAAT Approval?

Accepted Answer

Requirements depend on the aircraft, operation and exact location. For UAS over 25 kg, the CAAT checklist covers aircraft registration, pilot certification for the aircraft type/model, site-owner permission and other operational and airspace requirements. Big Great reviews the location and applicable requirements before confirming an operating date.

Question 7

Can Drone Cleaning Be Done in Bangkok?

Accepted Answer

The exact location must be checked first. Bangkok includes controlled and restricted airspace, so feasibility depends on current CAAT/AIP information and the applicable authorization at the time of operation.

Question 8

Do You Need to Control the Ground Area?

Accepted Answer

It depends on the risk assessment and site conditions. CAAT over-25 kg guidance includes ground-risk measures such as a buffer area, controlled ground area or shelter and selection of a suitable operating window. Some sites may therefore require temporary access control or coordinated work zones.

Question 9

Must the Drone Remain in Visual Line of Sight?

Accepted Answer

For the operating framework being prepared, CAAT requirements call for the remote pilot and/or visual observer to maintain visual line of sight with the aircraft throughout the operation. Building geometry and pilot/VO positioning are therefore part of site planning.

Question 10

Is Insurance Required?

Accepted Answer

Applicable insurance is part of the operational requirements. The CAAT over-25 kg checklist effective 14 February 2025 specifies third-party liability coverage for life and property of at least THB 2 million, with the policy covering the operating period.

Question 11

How Long Does Approval Take?

Accepted Answer

There is no single guaranteed lead time for every site. Timing depends on location, airspace, scope, applicable permissions and the authorities involved, so project information should be reviewed before an operating date is confirmed.

Question 12

Can Drone Cleaning Be Used on Curtain Wall Glass?

Accepted Answer

It can be considered, but glass type, coating, surface condition, seal/joint areas and cleaning requirements should be reviewed first. Architectural glass can include clear, tinted, reflective, Low-E and other coated surfaces that may require different cleaning procedures.

Question 13

Is the Same Cleaning Setup Suitable for Every Glass Surface?

Accepted Answer

No. Surface and coating should be reviewed before water delivery, nozzle, working distance and cleaning method are selected. Where specifications are unknown or special coatings are present, manufacturer information or a test area may be needed before the full scope begins.

Question 14

Does the Drone Always Use 4,100 PSI on the Surface?

Accepted Answer

No. The 4,100 PSI figure is the pressure-washer equipment rating, not evidence that the surface receives that pressure. Hose, nozzle, spray pattern, working distance and operating parameters all affect the cleaning setup, so Big Great does not apply one pressure to every surface.

Question 15

Can Drone Cleaning Remove Every Type of Stain?

Accepted Answer

No. Some soiling responds well to water-based cleaning, while bonded deposits, mineral deposits, sealant residue, construction contamination or stains requiring mechanical action may need another method. Method selection starts with the soiling and stain assessment rather than the drone alone.

Question 16

Do You Use Chemicals?

Accepted Answer

Chemicals are not assumed by default. Any cleaning agent should be considered against the surface, coating, type of soiling and manufacturer requirements, starting with the mildest method that can achieve the required result.

Question 17

What About Water Runoff?

Accepted Answer

Water runoff is part of site planning, including ground area, pedestrian and vehicle movement, drainage, adjacent properties and site activities. The control method therefore depends on the building and cannot be standardized for every site.

Question 18

Can Every Solar Farm Use Drone Cleaning?

Accepted Answer

No. Panel layout, row spacing, tilt, obstacles, ground area, water supply, hose routing, module requirements and operating conditions should be reviewed first. Drone cleaning is one cleaning option, not the default solution for every solar site.

Question 19

How Often Should Solar Panels Be Cleaned?

Accepted Answer

There is no single cleaning frequency for every site. The optimal interval depends on soiling rate, rainfall, cleaning cost, value of recovered energy, PV efficiency and local conditions, and some sites may suit seasonal or condition-based cleaning rather than a fixed schedule.

Question 20

Does Rain Clean Solar Panels Naturally?

Accepted Answer

Rain can remove some types of soiling, but it should not be assumed to restore panels fully every time. NREL research has shown that at sites with significant pollen, performance may not fully recover after regular rainfall.

Question 21

How Much Can Cleaning Improve Power Output?

Accepted Answer

There is no single percentage that applies to every project. Soiling loss varies with climate, dust or pollen, pollution, tilt, rainfall and site conditions. Site performance data or soiling measurements are more appropriate for cleaning strategy, so Big Great does not use a universal power-uplift claim.

Question 22

Can High-pressure Water Be Used on Solar Panels?

Accepted Answer

The module manufacturer’s requirement must be checked. There is no single maximum pressure for every module: manufacturers such as LONGi, Canadian Solar and First Solar publish different limits, so the current model-specific manual should be reviewed before the cleaning configuration is defined.

Question 23

Does Water Quality Matter?

Accepted Answer

Yes. Several manufacturers specify water-quality considerations such as low mineral content, near-neutral pH or RO/DI water in some cases to reduce mineral residue or surface issues. Water specification should therefore follow the module requirements rather than one universal standard.

Question 24

Do You Use Detergent on Solar Panels?

Accepted Answer

Water is the starting point for many modules, but if soiling requires a cleaning agent the manufacturer requirements should be checked first. Different manufacturers publish different restrictions and approved or discouraged chemicals.

Question 25

Can Solar Panels Be Cleaned at Any Time of Day?

Accepted Answer

Module temperature, water temperature, production and operating conditions should be considered. Some manufacturers specify temperature-difference limits or recommend lower-light periods to reduce thermal stress, production impact or electrical risk.

Question 26

What Information Do You Need for an Initial Review?

Accepted Answer

For facade/building exteriors: location, building photos, approximate height or floors, surface type, approximate area, access conditions and surrounding activity. For solar: location, installation type, panel layout or photos, approximate area, module information if available, water source and site conditions.

Question 27

Is a Site Visit Always Required?

Accepted Answer

An initial suitability review can start from photos, drawings, location and project information. If the information is insufficient or site complexity affects safety or method selection, a site survey may be required before the final proposal or operation planning.

Question 28

How Is Pricing Calculated?

Accepted Answer

Pricing should not be based on area alone. Factors may include surface or panel area, soiling condition, building or array geometry, access, ground area, water and logistics, operating window, site controls and project requirements. Sites with the same area can therefore have different scope and cost.

Question 29

Can Drone Cleaning and Rope Access Be Used Together?

Accepted Answer

A hybrid approach can be considered. For example, drone cleaning may suit large open facade areas while rope access is used for recesses, detailed cleaning, inspection or repair. Method selection depends on the actual site assessment and scope.

Question 30

When Can the Work Start?

Accepted Answer

The operating date depends on site readiness, project coordination, weather and applicable permissions. Big Great therefore does not guarantee one standard lead time for every location before project requirements are reviewed.

Frequently Asked Questions

Drone Cleaning & Site Suitability

CAAT & Operational Requirements

Facade, Glass & Surface Compatibility

Solar Panel Cleaning

Project Planning & Pricing

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