How LED Lighting Cut One Maryland Warehouse's Energy Bill by 41%

Metal halide lighting has been the workhorse of Maryland warehouses for decades. It's bright, durable, and familiar. It's also one of the most inefficient lighting technologies still in widespread commercial use — and for a business running 10-hour shifts six days a week, those inefficiencies add up fast.

Consider a typical scenario: a 60,000 sq ft distribution warehouse in the Baltimore–Washington corridor, running 400-watt metal halide high bays across 120 fixtures. With a $0.12/kWh rate and 3,000 annual operating hours, that lighting system costs roughly $17,280 per year to run — before factoring in maintenance costs for burned-out bulbs, ballast replacements, and the 15–20 minute warm-up time that costs productivity every time the lights cycle.

The Upgrade: Metal Halide to LED High Bays

A facility like this is a textbook candidate for an LED upgrade under EmPOWER Maryland's commercial lighting program. Here's what a typical upgrade looks like:

• Replace 120 × 400W metal halide fixtures with 120 × 150W LED high bays (equivalent or better light output)
• Install occupancy sensors in low-traffic areas (receiving dock, restrooms, storage aisles) — reducing average wattage by an additional 20–30%
• Upgrade exit and emergency lighting to LED simultaneously

The result is a system that uses 250 watts less per fixture — a 62.5% reduction at the fixture level. When combined with occupancy sensor controls, the effective reduction in lighting energy consumption reaches 70–75%.

The Numbers: Project Cost and Payback

A 120-fixture LED upgrade with occupancy sensors in a 60,000 sq ft facility typically runs $28,000–$42,000 installed, depending on fixture selection and electrical work required. Under EmPOWER Maryland's commercial lighting program (up to 80% rebate for small commercial customers), the out-of-pocket cost after rebates can be reduced to $8,400–$12,600.

The Cooling Load Reduction Bonus

One benefit that often gets overlooked in lighting ROI calculations: every watt of reduced lighting is also a watt of reduced cooling load. Metal halide and fluorescent fixtures emit substantial heat. In a warehouse that runs air conditioning or is temperature-controlled for product storage, that heat has to be removed by the HVAC system.

Replacing 400W metal halide fixtures with 150W LEDs removes 250 watts of heat per fixture — 30 kW of heat load across 120 fixtures. In a BGE or Pepco service territory where electricity costs $0.12–$0.15/kWh and the building runs air conditioning for 5 months, this indirect savings can add $1,500–$2,500 per year on top of the direct lighting savings. That's the "41% total facility reduction" figure — combining both direct and indirect savings.

What the Process Looks Like

For a warehouse LED upgrade processed through Maryland Smart Energy, the typical project timeline is:

• Week 1: No-cost walkthrough assessment — fixture count, current energy consumption, rebate eligibility confirmation
• Week 2: Lighting design proposal with fixture specifications, cost, rebate estimate, and projected savings
• Week 3–4: Equipment procurement and scheduling
• Installation day: Licensed electrician crew installs new fixtures during off-hours or on a weekend to minimize operational disruption
• Post-install: Maryland Smart Energy submits rebate application to the utility on your behalf. Rebate check typically arrives 4–8 weeks after application approval.