Occupancy Sensor Lighting Payback Calculator

Motion/occupancy sensors cut lighting runtime 30-70% in common areas.

Fixtures

Fixture watts

Current hours / yr

Sensor $/fixture

Hours reduction %

$/kWh

Payback months

116.6

Annual savings

$386

Total cost

$3,750

How the math works

Hours saved = current × reduction. Savings = fixtures × watts × hrs saved / 1000 × rate.

30 × 30 × 3,575 / 1000 × $0.12 = $386/yr. $3,750 cost. 116.6 months (9.7 yr).

How to Use

Enter fixtures.
Enter fixture wattage.
Enter current run hours.
Enter sensor cost per fixture.
Enter run hours reduction %.
Enter electricity rate.
Read payback.

Frequently Asked Questions

Best applications?

Storage rooms: 70-90% runtime reduction. Stairwells: 60-80%. Bathrooms: 50-70%. Offices: 30-50%. Corridors (residential): 40-60% (safety lighting at dim-down). Amenity rooms (gym, game room, etc.): 50-70%. Parking garages: 30-50%. Always-on (lobbies, primary circulation): exclude.

Cost?

Simple PIR sensor (passive infrared): $25-80 each. Dual-technology (PIR + ultrasonic): $60-150 each. Installation: $50-200 per sensor. Retrofit integration with existing fixtures: $5-40 additional. Average per-fixture retrofit: $75-200 total. Volume discount 20-40% on large projects.

Controls evolution?

Basic occupancy sensor: on/off based on motion. Advanced: dim-down to safety level when unoccupied. Connected/networked: centralized reporting + schedule + integration. Wireless mesh: retrofit without rewiring. Enterprise lighting control (Lutron, Acuity, Daintree): full scheduling + tuning. Capex scales 2-5× from basic to networked.

Codes + rebates?

ASHRAE 90.1, CA Title 24, IECC: require occupancy sensors in many spaces for new construction. Retrofit: voluntary but common for code-compliant upgrades. Rebates: prescriptive $15-75 per sensor typical. DLC (DesignLights Consortium) qualified products. 179D deduction: qualifying retrofit. Utility demand response: advanced sensors enabling DR get $100-500/sensor additional incentive.