Installing solar panels on a carport with a thin sheet-metal roof presents a challenge many installation companies prefer to avoid: the structure isn’t always designed to support additional loads, and a poor installation can compromise both the system’s performance and the integrity of the roof itself. At Guaira-Solar, we took on that challenge in a recent project in Independencia, Guairá, where we installed a system of 18 solar panels, a 10 kW inverter, and a 5 kW lithium battery, all on a lightweight sheet-metal carport structure.
The challenge: thin sheet metal doesn’t mean “impossible to install”
Many property owners in Paraguay assume that if their carport or shed has a thin sheet-metal roof, it isn’t suitable for solar panels. It’s a valid concern: without proper structural reinforcement, the weight of the panels and mounting rails can cause bending, leaks, or even medium-term damage.
However, with the right structural design, a serious technical assessment, and mounting materials designed for this type of surface, it’s entirely possible — and safe — to install a robust solar system on thin sheet metal. The key lies in correctly distributing the weight and anchoring the structure to the roof’s actual support points (purlins and rafters), not just to the sheet metal itself.
How we approached the installation for this project
For this particular system, we followed a process specifically designed for lightweight roofs:
- Prior structural assessment: before installing a single panel, we checked the condition of the purlins, the spacing between supports, and the carport’s actual load capacity.
- Anchors distributed at structural support points: the aluminum rails are fixed directly to the roof purlins, not just the sheet metal, to transfer the weight to the load-bearing structure.
- Professional sealing of every penetration: each fixing point is properly sealed to prevent leaks — a critical detail during the rainy season in Guairá.
- Balanced distribution of the 18 panels: instead of concentrating the weight in one section, the modules are spread evenly across the entire available surface of the carport.
System specifications
This project combines components suited for a more demanding residential or small-business consumption than a basic system:
- 18 high-efficiency solar panels, distributed across the carport structure
- 10 kW inverter, capable of handling higher simultaneous loads: air conditioners, pumps, power tools, or several devices at once
- 5 kW LiFePO4 lithium battery, to keep essential loads running during an ANDE power outage
Why a 10 kW inverter with “only” 18 panels?
This is a common technical question. Sizing a solar system doesn’t depend solely on the number of panels, but on the property’s peak consumption. A 10 kW inverter allows:
- Handling the simultaneous startup of motors and compressors (air conditioners, water pumps, power tools)
- Leaving room for future growth to add more panels later without needing to replace the inverter
- Operating more efficiently when multiple electrical loads run at the same time — common in properties with workshops, businesses, or high electricity consumption
The role of the lithium battery in a system of this scale
With a 5 kW LiFePO4 lithium battery, this system doesn’t completely eliminate dependence on ANDE, but it does protect the most important loads during an outage: lighting, refrigerator, router, water pumps, and sensitive electronics. The battery charges from the day’s solar surplus and kicks in automatically in case of a grid failure, without manual intervention.
Advantages of this type of installation on thin sheet-metal carports
- Making use of existing structures: there’s no need to build a new structure or fully reinforce the roof, as long as the anchoring work is done correctly.
- Dual use of the space: the carport continues protecting vehicles or equipment while generating energy for the property.
- Accessible solution for sheds and storage buildings: many rural and semi-rural properties in Guairá have this type of roof, expanding access to solar energy without major construction work.
- Faster installation: since it doesn’t require deep structural changes, installation time is reduced compared to fully reinforcing a roof.
Common mistakes when installing on thin sheet metal (and ones we avoid)
- Fixing rails directly to the sheet metal without reaching the structural purlin
- Not distributing the weight of the panels evenly across the surface
- Using low-quality sealant at drilling points, causing leaks months later
- Underestimating the roof’s load capacity without a prior technical assessment
Does your carport or shed have a thin sheet-metal roof? Here’s what you need to know
If you’re considering installing solar panels on a similar structure, the first step is an on-site technical assessment. Not all sheet-metal roofs are the same: the profile type, the spacing between purlins, and the overall condition of the structure determine which type of anchoring and panel distribution is best suited for your particular case.
Frequently asked questions
Is it safe to install solar panels on a thin sheet-metal roof?
Yes, as long as the installation is done by fixing the structure to the support purlins (not just the sheet metal) and with a prior technical assessment of the load capacity.
Why choose a 10 kW inverter if I still have few panels?
It allows better handling of consumption peaks from motors and equipment, and leaves room to expand the system with more panels in the future without changing the inverter.
Is the 5 kW battery enough for the whole house during an outage?
It’s designed to cover essential loads (lighting, refrigerator, pumps, router, electronics) during an outage, not necessarily 100% of the property’s total consumption.
Can the roof leak through the mounting holes?
No, as long as the installation is done with proper sealing at every fixing point — something we check as a standard part of every project.
Does your carport or shed have a sheet-metal roof and you want to make use of that space?
At Guaira-Solar, we are a German family business based in Independencia, Guairá, specializing in solar systems adapted to different types of structures and roofs, including lightweight sheet-metal surfaces. Contact us for a Free consultation.
