Car dealership in Tucson, TEP Rate LGS-TOU. Massive outdoor lighting for the lot ? 180 fixtures at 400W metal halide. Total lighting demand is 72 kW. All lights come on simultaneously at dusk via photocell. That 72 kW hits in a single 15-minute interval every evening. During winter months when dusk falls during the on-peak TOU window, those lights are contributing to on-peak demand charges. Summer dusk is after the peak window so they dont.
Demand charge impact of outdoor lighting on commercial accounts
Larry ? car dealerships are great demand audit targets because of the lighting. LED conversion cuts the per-fixture wattage from 400W to 100-150W. Same light output, 60-65% demand reduction. For 180 fixtures thats dropping from 72 kW to about 25 kW. Plus LED fixtures can be staged ? timer-controlled zones that light up sequentially over 15-20 minutes rather than all simultaneously.
Karen ? LED conversion makes sense on energy savings alone but the demand charge savings accelerate the payback. The dealership owner quoted $85,000 for full LED conversion. Energy savings plus demand savings plus maintenance elimination pays back in 2.5 years. Adding demand management through staged zones could push peak lighting demand even lower.
Scottsdale dealerships are converting to LED rapidly. One angle I recommend: separate the lot lighting onto its own meter with an outdoor lighting tariff. APS has Rate E-36 for outdoor lighting that has no demand charge ? flat per-kWh rate. If the lot lighting qualifies, you eliminate the demand component entirely for that load.
Gina ? TEP has a similar outdoor lighting tariff TLS. Checking eligibility for the dealership. If the lot lighting can go on TLS with no demand charge, the entire 72 kW of lighting demand comes off the main building meter. Building demand drops from 195 kW to 123 kW. Thats a different tariff tier with a lower per-kW demand rate. Double savings ? reduced demand AND lower rate.
Final outcome: dealership went with LED conversion ($78,000 after rebates) AND separate outdoor lighting meter on Rate TLS. Building demand dropped to 118 kW qualifying for a lower tariff tier. Combined annual savings: $31,200 from demand charge reduction, $18,400 from energy savings, $4,800 from maintenance elimination. Total $54,400 annual savings. Payback under 18 months.