Over Easy Solar Panel: Your top choice for flat roof installations
Flat roofs offer excellent potential for solar panel installations, thanks to their wide, open surfaces and design flexibility. However, roof load limitations and the potential for intrusive fastening can complicate the installation process—such as the added weight from ballasted systems or the risk of damage from invasive mounting methods.
Over Easy Solar eliminates those challenges with a purpose-built solution designed specifically for flat roofs. Our innovative panels combine lightweight construction with smart, low-impact mounting to make installation faster, safer, and more efficient—without compromising your roof's integrity.
How do Conventional Solar Panel work on Flat Roof
When putting conventional solar panels on a flat roof, the angle they are set at significantly impacts how much power they produce. For south-facing installations, an angle around 30 to 35 degrees is typically optimal. However, on flat roofs, an east-west orientation with a gentler 10 to 15-degree tilt often proves more effective for capturing sunlight throughout the day, while also aiding in self-cleaning and minimizing shading. To achieve these specific angles, the PV substructure can be directly screwed to the roof truss through the flat roof, ensuring a secure connection. Alternatively, the frame supporting the panels can be glued to the roof surface and additionally weighted down for stability.
Roof Load Limits : The Primary Constraint for Rooftop Solar
The most common way to secure regular solar panels on flat roofs involves using heavy materials like gravel or concrete blocks to weigh them down. However, this added weight can sometimes be too much for the roof to handle, limiting how the number of solar panels installed. As a result, many flat roofs are not able to use their full potential to generate maximum solar energy. This reliance on heavy ballast is a significant drawback, often preventing homeowners and businesses from maximizing their solar capacity due to roof load limitations. In addition to weight, the success of a rooftop solar installation also heavily depends on the roof's current condition, its exposure to strong winds, and the potential for damage caused by intrusive fastening methods.
Essential Considerations for Flat Roof Solar Panel Installation
While roof load is a primary concern for solar installations, ensuring optimal energy production involves considering other crucial factors. This section explores essential aspects beyond just weight, including the roof's existing condition and its ability to withstand the installation, the impact of wind exposure, and the potential for damage caused by different mounting techniques, particularly those that penetrate the roof surface
Roof Material and Condition
The type of roof surface - such as bitumen, synthetic membrane, or metal - directly affects the compatibility and safety of solar panel installation. Some materials are not ideal for certain mounting systems, especially if they can’t support fasteners or withstand the pressure from ballasted setups. Additionally, the existing condition of the flat roof plays a critical role: aged, weathered, or damaged surfaces may not handle the added weight or mechanical stress of a solar array. A detailed inspection ensures the roof is both material-compatible and structurally sound, helping to prevent future issues and maximize system lifespan.
Wind Exposure and Building Height
Wind load is another critical consideration, especially for taller buildings. Structures at greater heights or in wind-prone regions require additional ballast to prevent solar panels from shifting or lifting. This increases the total load on the flat roof, making it even more important to evaluate the building’s capacity and choose a system designed to perform under these conditions.
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Damage from Intrusive Fastening
Traditional mounting systems often require drilling into the roof or using intrusive fasteners, which can undermine the integrity of the roof’s membrane. This can lead to potential leaks and other forms of damage over time, resulting in long-term maintenance issues. While fastening systems are necessary to secure solar panels, using non-intrusive solutions can significantly reduce these risks, providing a more reliable installation without compromising the roof’s waterproofing.
Weakening of Roof Integrity
Drilling into the roof can weaken its structure, diminishing its overall durability and its capacity to handle additional weight. Preserving the roof’s structural integrity is crucial to ensure the long-term performance and stability of both the roof and the solar system.
Risk of Leaks
Intrusive fasteners that penetrate the roof’s protective layer heighten the risk of leaks and water damage. Maintaining the integrity of this protective layer is essential to ensure the roof remains functional, leak-free, and durable over time.
Higher Maintenance Costs
The damage caused by intrusive fasteners can lead to costly repairs in the future. Roof leaks and structural issues often require expensive maintenance, making it essential to minimize these risks with a more secure, non-invasive mounting system.
Why Over Easy Solar Panel is the solution for your flat roof
Over Easy Solar’s vertical bifacial panels tackle flat roof challenges with no ballast required, reducing roof load and preventing intrusive mounting. Our design maximizes energy production, optimizes energy consumption, and offers numerous other benefits for a smarter, safer installation.
Maximized Energy Production
Captures more sunlight, maximizes energy during high-cost periods, and performs reliably in snow, dust, and low sun, ensuring increased energy production throughout the year.
Fits All Flat Roof Surfaces
Our photovoltaic system is suitable for a wide variety of roof types, e.g. for installation on a bitumen flat roof. It does not need to be elevated and can be flexibly adapted to different materials and requirements. Free access to the roof facilitates maintenance and inspection. If necessary, the flat roof PV modules can also be removed quickly and easily.
Optimized energy consumption
East-west oriented bifacial solar panels produce the most electricity in the morning and evening. This helps homes use energy better and reduces the need for battery storage.
No Ballast, No Roof Penetration
How are Over Easy vertical solar panels installed on a flat roof?
Our wind-resistant solar system can be mounted without roof penetration. It eliminates the need for heavy ballast or structural fixings and weighs just 11 kg/m² thanks to its lightweight construction. Now PV systems are also possible on roofs with structural restrictions that were previously unsuitable for solar energy.
Solar Boost with Roof Albedo
The roof's reflection (Albedo) can increase energy production by more than 30% on bright surfaces. This effect is especially advantageous in snow-affected regions, keeping your system reliable when traditional panels are covered. For instance, in Tromsø, our units outperformed conventional systems by 54%, yielding 747 kWh/kWp annually compared to their 485 kWh/kWp.
LATEST FLAT ROOF PROJECTS
We're proud to showcase our latest flat roof vertical solar panel installations—an innovative and space-efficient solution that transforms unused roof space into a source of clean, renewable energy. A huge thank you to our incredible partners and forward-thinking customers for embracing the transition to sustainable power. Your commitment is not only reducing carbon footprints but also making the most of every square foot of your buildings. Together, we’re building a cleaner, smarter energy future.
Amersfoort, Netherlands
Blussuvoll skole, Trondheim
Ullevaal Stadion, Oslo
UIB Juss, Bergen
Find Flat Roof Solar Grants & Incentives
Ready to unlock the potential of your flat roof with clean, sustainable solar energy?
Flat roofs offer an ideal surface for solar panel installations — and across Europe, there are numerous financial support programs designed to help you make the switch. From local incentives to national grants, funding is available to significantly reduce the upfront cost of installing solar panels on flat roofs for homes, businesses, and public buildings.
Take advantage of these programs to transform unused roof space into a source of long-term energy savings and environmental impact. Whether you're a property owner, company, or institution, you may qualify for grants or subsidies that make solar more accessible than ever.
P.S. While we strive to provide the most up-to-date information, grant programs and eligibility criteria can change. We strongly encourage you to cross-check the details and confirm the latest requirements directly with the relevant grant-providing authorities or official government resources in Europe.
Pronovo: One-off remuneration (EIV)
Pronova is Switzerland’s national incentive programme that provides one-off investment contributions to support the installation of photovoltaic (PV) systems. This financial assistance significantly reduces the upfront cost of solar panel installations and is particularly well-suited for flat roof projects, which offer optimal conditions for solar energy production.
The programme includes three main types of one-off remuneration. The KLEIV scheme supports small PV systems with an output of less than 100 kWp. For larger systems with an output of 100 kWp or more, the GREIV scheme applies. Additionally, the HEIV category offers a high one-off remuneration for PV systems ranging from 2 kW to 149.99 kW that operate without self-consumption.
France’s Feed-in Tariffs for Solar Energy
France’s feed-in tariffs (FITs) are a government-backed incentive designed to encourage the adoption of solar energy by offering fixed payments for electricity generated by solar systems and fed into the national grid. These tariffs provide a reliable, long-term income stream for system owners.
The rates vary depending on the size of your installation:
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Up to 3 kW: €0.0987/kWh
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3 to 9 kW: €0.0839/kWh
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9 to 36 kW: €0.1295/kWh
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36 to 100 kW: €0.1126/kWh
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100 to 500 kW:
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€0.1023/kWh (for connections before March 27, 2025)
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€0.0950/kWh (for connections between March 28 and June 30, 2025)
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FAQs about Over Easy Solar Panels on a flat roof
What is the recommended orientation for your solar panels?
For the best performance, we recommend installing our system in an east-west facing orientation. This setup works perfectly with our bifacial panels, taking advantage of the unique double energy peak to capture more energy. It helps generate power during the high-value periods—like early morning and late evening—when electricity prices are at their peak. Plus, vertical bifacial solar panels offer much higher capture rates, which means better financial returns, especially as dynamic pricing becomes more common. In the long run, this setup can give you up to 50% higher returns per installed kWp compared to traditional panels.
Do your solar panels work with standard inverters?
Absolutely! Our systems are fully compatible with standard solar inverters, provided they are correctly sized. The recommended inverter size will be detailed in the installer report provided by us or your trusted Over Easy Solar partner. Also, do check out our blog post on how to choose to correct inverter size for your flat roof solar panels.
What are the warranties for your product?
You can be confident in the enduring performance of our systems, as We offer a 15-year product warranty and a 25-year performance warranty, guaranteeing the sustained output and efficiency of your investment. This dual warranty structure underscores our commitment to quality and ensures your peace of mind for decades to come.
Can I use PV Sol to plan a project with Over Easy Solar’s solution?
Because standard PV planning software like PV Sol isn't ideal for vertical solar installations, we've created our own specialized tool. However, if you prefer using PV Sol or similar software, our team can supply you with a PAN file specifically formatted to help with your vertical system design. Furthermore, Over Easy Solar offers the VPV Planner, our in-house, custom-built planning tool designed to streamline the process for vertical PV projects. This tool empowers our partners to quickly evaluate a project's viability in the early phases, generating a preliminary plan in approximately five minutes.
Flat Roof Solar Panel Specifications
Double Energy Production
The industry-leading 96% bifaciality makes it ideal for east-west installations, maximizing energy production during peak pricing
Weight
Only 11 kg/sqm and ballast free
High Albedo
Reflected light from surfaces boosts energy production by up to 40 %
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Design
The world's first fully pre-assembled photovoltaic system - including integrated substructure, smart cabling and bypass diode for maximum efficiency.
Transport
Patented stacking mechanism for easy logistics
Superior Element Resistance
The vertical orientation reduces panel exposure to the elements, minimizing risks like dust accumulation and hail damage