The comparison in 2026
Bifacial solar panels generate from both front and rear surfaces — capturing reflected light from the surface beneath the panel. For UK rooftop farm installs, bifacial gain is typically modest. For ground-mount, bifacial economics improve significantly.
Detailed comparison
Bifacial gain. The additional generation from the rear surface depends on rear surface albedo (reflectivity). White concrete: 25-30% rear surface gain over monofacial equivalent. Green grass: 8-15%. Dark soil: 5-8%. Typical UK rooftop on profiled steel: 3-7%. Cost premium. Bifacial 540W modules: £100-£115 landed UK. Monofacial 540W: £85-£100. Premium: 5-10%. ROI calculation. For a 200 kW rooftop install: monofacial £200,000; bifacial £210-220,000. Bifacial annual generation 4-7% higher = approximately 7,200-12,600 additional kWh/year = £1,500-£2,800 additional annual saving. Bifacial premium pays back in roughly 5-7 years on top of the system payback. When bifacial wins. Ground-mount installations (especially on grass/white-concrete surfaces): bifacial gain typically 15-25%. Roof-edge installations with reflective adjacent surfaces. East-west orientations where rear surface captures different time-of-day reflections. When monofacial wins. Standard pitched rooftop installs on profiled steel: bifacial gain too small to justify premium. Cost-sensitive installs. Recommendation. For UK farm installs in 2026: monofacial as default for standard rooftop. Bifacial for ground-mount installations where the rear-surface gain is material. We model both options where bifacial is being considered.
How to decide for your specific install
The right choice depends on the specifics of your farm: roof geometry; load profile; capital sensitivity; future expansion plans; long-term operational priorities. We model multiple specification scenarios in every feasibility study where the choice is material. Send us your half-hourly meter data and building dimensions — we deliver a free desk feasibility within 7 working days, including specification recommendations with clear rationale.
Common questions
What do you typically recommend?
Depends on the specifics of the site. Our default approach is documented in the comparison above; we model alternative scenarios where the project requirements suggest different specification choices.
How material is the difference in practice?
Most specification differences sit at the margin of project economics — typically 2-10% impact on overall 25-year NPV. The fundamental decision (whether to install PV at all) is far more material than the specification choice within PV.
Can we change specification later?
Some changes possible without complete reinstall (e.g., battery brand, inverter replacement at end of life). Other choices (e.g., optimised tilt vs roof-pitch following) are baked in at install. Specification decisions for permanent elements should be made carefully at design stage.
Do you have a preferred manufacturer or product?
We're independent of any specific manufacturer. Every quote includes specification recommendations specific to the site geometry, the farm's strategic priorities, and current market pricing. We never push a specific brand without rationale.