Green roofs and solar power go hand in hand — both reduce carbon, improve biodiversity, and make better use of underutilised roof space. But if you already have a bio roof in place, adding solar PV can feel risky or overly complicated so what is the retrofit solar solution for existing green roofs?
We recommend OverEasy Solar as the go-to retrofit solution. At PV Plus, we’re proud to be one of the only UK-approved installation partners, and we’ve seen first-hand how this system transforms what’s possible on existing green roofs.
Why retrofit solar onto a green roof?
If your building already has a green roof — whether sedum, wildflower, or meadow-style — you’ve made a great start. But adding solar can take things even further:
- ✅ Lower building emissions and energy bills
- ✅ Improve your ESG reporting or meet Net Zero targets
- ✅ Generate clean energy on-site with minimal disruption
- ✅ Unlock extra roof value without compromising biodiversity
The challenge? Most solar systems weren’t designed to work with green roofs — especially ones already in place. That’s where OverEasy is different.
A retrofit solar solution for existing green roofs
OverEasy Solar’s vertical bifacial PV units were built with green roof compatibility in mind from the start. The xM-2 QUATTRO-200S sits lightly on top of the vegetation — with no need to cut into the membrane, move the substrate, or compromise drainage.
Here’s what makes it ideal for retrofit projects:
- No ballast or fixings needed – the system sits securely without penetrating the roof
- Weighs just 11kg/m² – far lighter than traditional ballasted systems
- Zero disturbance to the vegetation – no uprooting, reshaping, or new build-up required
- Full access for maintenance – the system keeps plant areas visible and reachable
- Improves plant health – the vertical panels reduce roof temperatures and slow down evaporation during dry spells
- Preserves biodiversity – ideal for sedum and meadow-style roofs, supporting both flora and fauna
The OverEasy system has been wind-tested, fire-safety tested, and is compliant with key standards for both solar and building integration. It’s the only PV solution we’ve seen that is truly retrofit-friendly for green roofs.
How is OverEasy different from the conventional method?
Traditionally, retrofitting solar onto an existing green roof involves a major rebuild. Here’s what that usually looks like:
- Remove the existing vegetation and substrate
- Install a new biosolar mounting system such as the one offered by Bauder or Optigreen — often one that uses trays or frames fixed or held down by the weight of the green roof materials
- Ballast the system using re-added substrate, gravel, or other weight
- Rebuild and replant the green roof around the new structure
✅ The positives:
- Fully integrated “biosolar” systems can look neat and uniform
- Offers the chance to upgrade or redesign your roof ecology
- May suit new-build or major refurbishment projects where the roof is being replaced anyway
❌ The downsides:
- Costly and labour-intensive — often requires full removal and reinstallation
- Risk of damaging existing waterproofing, insulation, or vegetation
- Long programme and coordination across multiple trades
- Adds significant weight, making it unsuitable for some existing roof structures
- Disruptive to established flora and biodiversity
Real-world results — fast installs, high performance
Each OverEasy unit arrives prefabricated with mounting frame, bifacial panels, and cabling — ready to click into place. Installation takes just 15 minutes per kWp, and with no heavy lifting gear or fixings required, we can install without damaging your roof, your plants, or your existing warranty.
Plus, the vertical bifacial design delivers a unique energy profile — capturing light from both sides and generating more power in the mornings, evenings, and winter months. That means better self-consumption, especially for buildings with steady daytime loads like schools, offices, and public buildings.
PV Plus: Your green roof solar experts
We’ve delivered commercial solar for over a decade and have specialist experience working with green roofs, biodiverse sites, and sensitive environments. As one of the only UK partners approved to supply and install OverEasy Solar, we bring both the technical know-how and the care needed to make your retrofit project a success.
If you have an existing green roof and want to explore your solar options — without disrupting the ecology or fabric of the roof — we’d love to help.
Let’s turn your living roof into a clean energy asset.
Message us or book a site assessment today.
