With NEM 3.0 drastically reducing the export credit value in California, every extra watt produced during peak hours matters more than it used to. That's pushing a lot of us to reconsider higher-efficiency options for roof arrays — specifically whether bifacial solar panels are worth the modest price premium given the albedo available on a typical residential roof.

The theoretical rear-side gain on bifacial modules runs around 5-15% depending on mounting height and ground reflectivity. Over a flat or tilted rooftop with a light-colored surface (white TPO, light asphalt, gravel ballast), the real-world additional yield is usually closer to 3-7% — modest but compounding over the 25-year warranty period, especially when your NEM 3.0 export value is cents on the dollar.

Questions I'm trying to answer before committing:

• On a composition shingle roof with a standard rail mount, does the rear-side gain ever approach double digits, or is the clearance too tight?
• Is a slightly tilted flush mount better for bifacial than a steeper tilt (for rear exposure)?
• With NEM 3.0 shifting value toward self-consumption + battery, does the bifacial bonus matter less once most energy goes to a Powerwall anyway?

If anyone here has real installed data comparing mono-facial vs bifacial in CA post-NEM 3.0, would love to see numbers. Especially interested in Central Valley installs where the summer output delta should be most visible.