What is a bifacial solar panel?
A bifacial solar panel generates electricity from light reaching its front and rear surfaces. Albedo means the reflectivity of the surface beneath it [S1]. In an assumed example, 5% additional annual generation on a 100,000 kWh front-only baseline adds 5,000 kWh. Actual rear-side gain depends on the mounting and surroundings, rather than a universal uplift. Checked October 2026.
What does a bifacial solar panel mean for your site?
A bifacial solar panel is a photovoltaic panel that converts light arriving at both its front and rear into electricity [S1]. Why it matters for your site: a proposal should explain how light reaches the rear before adding extra generation to your business case.
Albedo is the reflectivity of the ground or roof surface. Bifacial gain is additional generation compared with a matching front-only arrangement, rather than the rear cell’s laboratory efficiency [S1]. A high rear efficiency rating cannot create sunlight that the mounting blocks.
Where can rear-side gain be useful?
Raised flat-roof arrays, solar carports and ground mounts are layouts worth assessing because their undersides can receive reflected light. IEA PVPS identifies array height, row spacing, surrounding reflectivity and rear shading as important design factors [S1]. A panel fitted close to an opaque roof needs a different assessment.
Request a drawing showing clearance, structural obstructions and the surface below. Use how commercial solar panels work for the electrical basics and ground-mounted business solar for the wider site decision.
How should you check an extra-generation estimate?
An illustration, not a quote: assume front-only annual generation of 100,000 kilowatt-hours (kWh), the unit of energy, and a modelled bifacial gain of 5%.
Additional energy = 100,000 × 0.05 = 5,000 kWh; total = 105,000 kWh. Both inputs are assumptions, not a benchmark for your roof.
Ask for the front-only baseline and rear contribution separately. Laboratory modelling tools account for rear illumination and array geometry [S2]. Request the albedo assumption and a lower-gain scenario so you can see how dependent the proposal is on reflected light.
Next step
Start with cut energy costs and the site check, then get matched with an installer that covers your area.
Piggy Pineapple Ltd operates this referral service. We refer enquiries to installer partners and may be paid a fee. Our owner holds shares in at least one partner. We name the proposed partner and disclose any shareholding our owner holds in it before passing on your details.
Common questions
Does bifacial mean twice the electricity?
No. Rear-side gain depends on available light and layout; the rear is not a second identical generation forecast [S1].
What does albedo mean in a solar proposal?
Albedo describes surface reflectivity. Ask which ground or roof reflectivity the model assumes [S1].
Can a light-coloured roof affect output?
Yes. Reflected light can reach the rear, but mounting height, spacing and shading also affect the gain [S1].
Are closely mounted roof panels certain to gain extra energy?
No. Request modelling of rear illumination for that mounting arrangement before counting additional generation [S2].
Should you accept a panel wattage without its test conditions?
Request the rating conditions and a separate site yield model; rear irradiance is an input to bifacial modelling [S2].
Ask about your site
Sources
- Bifacial photovoltaic technology and system design, IEA Photovoltaic Power Systems Programme,Last checked 19 October 2026
- Photovoltaic bifacial irradiance and performance modeling toolkit, National Laboratory of the Rockies,Last checked 19 October 2026