Finding Your Perfect Off-Grid Power Partner

Choosing the right solar panel for a campervan, motorhome, or caravan is a decision that extends far beyond simply selecting a wattage, although wattage is an important consideration. The panel must be a seamless partner to the vehicle, fitting securely and discreetly while providing a reliable source of power. This guide is designed to aid your selection process by matching specific solar panel types to the unique characteristics of different recreational vehicle roofs.

At Solar Technology, we offer four distinct solar panel styles: The Rigid Mono High Density (MHD) glass panel, the lightweight  Rigid SlimEdge panels, and the two semi-flexible options, the Flexi MHD and the Flexi standard. We have analysed the optimal application of each panel type across four common vehicle roof configurations - a campervan with a slightly curved metal roof with ridges, a VW campervan with a curved fibreglass pop-top roof, a motorhome with a flat floating metal roof, and a caravan with a curved aluminium roof.

Executive Summary: Your Quick-Reference Panel Picker

The selection of a solar panel is a direct function of the vehicle's roof type and the user's priorities regarding aesthetics, durability, and installation. While all panels convert sunlight into electricity, their physical attributes dictate their ideal application. The following table provides a high-level summary of the best panel for each specific roof configuration, with detailed explanations provided in the sections that follow.

Understanding the Panels

The range of solar panels for recreational vehicles offers a solution for nearly every need, with each type distinguished by its construction, materials, and physical properties. Understanding these differences is the first step toward making an informed decision.

The Rigid Panels: Powerhouses in a Frame

Rigid solar panels are the traditional choice for mobile power systems, known for their robust construction and proven durability.

Rigid MHD (Aluminium Frame & Glass)

The Rigid Mono High Density (MHD) solar panel represents the zenith of conventional solar panel design. It is a formidable unit built around a sturdy, anodised aluminium frame and protected by a durable glass panel. The core of its performance lies in the innovative shingled monocrystalline solar cells, which are designed to deliver superior efficiency in a smaller footprint compared to older technologies. This allows the panel to generate a significant amount of power per day—for example, a 100W panel can produce up to 600W per day, providing ample energy for off-grid travel.

Despite its power output, its physical dimensions and weight are critical considerations. A 100W Rigid MHD panel measures 1150x460x35mm and weighs 6.9 kilograms, making it the heaviest and thickest option in the line-up. This weight and bulk necessitate a secure, elevated installation using brackets, which is a key factor in its ideal application. Solar Technology backs the panel’s longevity with a robust 10-year module warranty, reflecting a high degree of confidence in its glass and aluminium construction.

SlimEdge Rigid (Aluminium Frame & 5-layer composite panel)

The SlimEdge rigid panel is a modern evolution of the traditional rigid panel, designed to address the challenges of weight and profile. It is a superior option for users who want the durability of a framed panel but require a lighter, less bulky solution. The primary material difference is the replacement of the glass top sheet with a tough, lightweight 5-layer composite panel. This material choice is significant, as it allows the panel to be up to 50% lighter than conventional rigid panels and gives it an ultra-thin 12mm profile.

Like its MHD counterpart, the SlimEdge utilises high efficiency shingled monocrystalline cells and is built with a sturdy anodised aluminium frame. This combination of advanced materials and cell technology provides a strong, aesthetically pleasing panel that retains the long-term durability expected of a framed unit. It also carries a 10-year panel warranty, demonstrating that the shift from a glass top sheet to a composite panel does not compromise the panel's long-term integrity.

The Material and Warranty Trade-off

The choice between the Rigid MHD and the SlimEdge rigid panel highlights a crucial design consideration. The Rigid MHD panel's glass top sheet is a heavy, time-tested material that provides excellent resistance to scratching and impact. In contrast, the SlimEdge's composite panel is a highly durable construction that offers a significant weight reduction and a lower profile. Both panels are engineered with strong aluminium frames and high-efficiency cells, and crucially, both are backed by the same 10-year warranty.

This equal warranty period suggests that, for general use, both material choices are considered to have a comparable lifespan. The decision is therefore not a matter of durability but a direct trade-off between weight and profile. A user concerned about minimising the load on a vehicle's roof or seeking a more discreet installation would gravitate towards the SlimEdge. In contrast, a user who prioritises the time-honoured durability of a glass panel would choose the Rigid MHD.

The Flexible Panels: Lightweight and Adaptable

Flexible panels, often called semi-flexible, are engineered for situations where a lightweight, low-profile, and contour-hugging solution is paramount, though there is a premium for flexibility.

Flexi MHD

The Flexible MHD solar panel combines the best of both worlds: the advanced cell technology of the MHD line with the adaptable nature of a flexible panel. At a mere 2mm thick and weighing only 1.9 kilograms for a 110W model, it is an ultra-lightweight and discreet option. Its top sheet is a tough ETFE material, specifically tested for resistance to extreme conditions such as saltwater spray and ultraviolet (UV) light.
This panel is designed for flat roofs as well as surfaces with "a slight curve," making it a perfect choice for campervans and boat decks. However, the physical flexibility and material choice are reflected in a shorter module warranty of 4 years.

Flexi Standard

The Flexible Standard panel is the classic semi-flexible option, known for its versatility and resilience. Its design features a durable, six-layer laminate with an ETFE top layer, providing extra toughness under challenging conditions. These panels are 4mm thick and are also rated for use on flat or slightly curved surfaces.

A key engineering feature of the Flexi Standard panel is the inclusion of built-in shading diodes, which are housed within the waterproof junction box. These diodes are designed to help prevent damaging "hot spots" that can occur when a panel is partially shaded, a common scenario on campervans and boats. Like the Flexi MHD, its durability is reflected in a more limited 2-year panel warranty.

Warranty and Practical Durability

The difference in warranty periods between rigid (10 years) and flexible (2-4 years) panels is a critical indicator of their expected long-term performance. While a flexible panel is rugged and tested for UV and salt spray resistance, its construction lacks the structural integrity and resistance to impact provided by a rigid panel's glass and aluminium frame. Flexible panels are more susceptible to damage from a direct impact, such as falling branches or walking on the surface.

Therefore, the choice is between two forms of durability. The rigid panel is a robust, long-term power solution that can withstand physical stress and impact. In contrast, the flexible panel offers a different form of durability—a resilience to bending and a low profile that makes it less susceptible to wind damage. This understanding is crucial for a customer to weigh the benefits of a lightweight, discreet installation against the long-term structural integrity and warranty of a rigid panel.