Heres the whole calculation so you have all the details.
CXB3590DB36V4000K 16 COBS @1.4A ON 1.813 PROFILE HEATSINK
25 SQ.FT. CANOPY 94% EFFICIENT DRIVER @10 CENTS PER KWH
Total power watts at the wall: 831.91
Cobs power watts: 782
Total voltage forward: 558
Total lumens: 154163
Total PAR watts assuming 10% loss: 430
Total PPF: 1947.9
PPFD based on canopy area: 838.68
PAR watts per sq.ft.: 17.2
Cob efficiency: 61.03%
Power watts per sq.ft.: 31.28
Voltage forward per cob: 34.89
Lumens per watt: 197.14
Heatsink riser thickness / number of fins / fin's length: 0.3in/6/0.95in
Heatsink area per inch: 100.94 cm^2
Total heat watts: 305
umol/s/W / CRI: 4.53 / 80CRI
COB cost dollar per PAR watt: $1.87
Electric cost
@12/12 in 30 days: $30.45
Electric cost @18/6 in 30 days: $45.42
Cost per cob: $50.17
Total cobs cost: $803