Money
Total value—Feed-in + avoided grid cost
Avoided grid cost—Solar used at home × retail price
Feed-in—Paid for exported kWh
Grid bill—Energy bought (excl. base fee)
Value per day
Avoided grid cost
Feed-in
Grid bill (down)
Car charging
Grid energy at the grid price; solar valued at the feed-in it replaced. “At cost” is what the charging really cost the household and a fair basis for billing a car separately; “all from grid” is what it would have cost without solar.