Why car parks beat warehouses on payback
The payback period on any LED upgrade depends on three things: wattage reduction, electricity tariff, and annual operating hours. Car parks win on all three compared to a typical warehouse.
A warehouse running two shifts operates roughly 3,120 hours per year (12 hours a day, 5 days a week). An underground car park in a residential or commercial building runs from about 6am to 2am every day of the year. That is 20 hours a day, 365 days a year, which equals 7,300 operating hours per year. More than twice the hours of a warehouse, on the same number of fittings.
The incumbent fittings in most car parks built before 2018 are 250W metal halide bulkheads or surface-mounted battens. These are typically replaced with 40W to 60W LED panels or bulkheads, depending on the ceiling height and bay layout. A 60W LED produces comparable or better illuminance to a 250W metal halide at the heights common in basement car parks (2.4m to 3.5m). That is a 76% reduction in watts per fitting, applied across 7,300 hours.
Quick comparison: A 250W metal halide fitting running 7,300 hours consumes 1,825 kWh per year. A 60W LED replacement consumes 438 kWh. The saving is 1,387 kWh per fitting per year. On a 50-fitting car park that is 69,350 kWh saved annually before any motion dimming.
The scenario used in this guide
All numbers below use a standard mid-rise residential or commercial building with 50 car park bays. The lights are currently 250W metal halide bulkhead fittings, running 20 hours a day, 7 days a week. The LED replacement is a 60W IP65-rated LED bulkhead, suitable for underground use.
Base scenario: 50 fittings, 250W metal halide to 60W LED
The $380 per fitting supply-and-install cost assumes a daytime planned installation using a licensed electrician, with no crane or cherry picker required. Typical underground car parks have flat ceilings at 2.4m to 3m, so installation is straightforward on a standard step ladder. Ceiling heights above 3.5m add time and cost.
State-by-state payback comparison
With 69,350 kWh of annual savings, the dollar value of those savings varies significantly by state. South Australia's commercial tariff sits around 42c/kWh while Victoria runs around 27c. Add state rebate schemes and the payback spread across Australia is substantial.
| State | Tariff | Annual saving | Rebate scheme | Net capital | Payback |
|---|---|---|---|---|---|
| SA | 42c/kWh | $29,127/yr | REPS $4,000 | $15,000 | ~6 months |
| NSW | 29c/kWh | $20,112/yr | ESS $4,000 | $15,000 | ~9 months |
| VIC | 27c/kWh | $18,725/yr | VEU $4,500 | $14,500 | ~9 months |
| WA | 31c/kWh | $21,499/yr | No state scheme | $19,000 | ~11 months |
| QLD | 28c/kWh | $19,418/yr | No state scheme | $19,000 | ~12 months |
Rebate values are indicative. ESS (NSW), VEU (VIC) and REPS (SA) calculate incentives based on verified energy savings certificates, and the actual dollar amount depends on the current certificate price at the time of installation. Engage a registered installer to confirm current rebate values before budgeting.
The motion dimming bonus
Underground car parks have periods of very low activity, typically overnight from around 10pm to 6am. Adding 0-10V dimming control to the LED fittings and connecting motion sensors allows the lights to dim to 20-30% output when no movement is detected, and ramp to full brightness within 1-2 seconds when a vehicle or person enters.
A conservative estimate: 8 hours per night at 30% output instead of 100%. That reduces consumption during those hours from 3,000W (50 × 60W) to 900W. Applied over 365 nights, the additional saving is around 5,500 kWh per year, or approximately $1,600 extra per year in NSW, $2,310 in SA.
Dimming bonus: 8 hrs/night at 30% output
Dimming-capable fittings add around $20-30 per fitting to the supply cost and require motion sensors at roughly $80-120 each (one sensor typically covers 4-6 bays). The dimming system pays back within the first year of operation in most cases.
Tip for property managers: Specify 0-10V dimmable fittings in all car park quotes, even if the body corporate does not approve the dimming controls upfront. Adding dimming capability later without swapping fittings is far cheaper than retrofitting non-dimmable lights.
Rebate eligibility in detail
Car park LED upgrades qualify under all three major state energy efficiency certificate schemes. Here is what each scheme requires.
NSW: Energy Savings Scheme (ESS)
The ESS creates Energy Savings Certificates (ESCs) based on verified lifetime energy savings. A registered Accredited Certificate Provider (ACP) handles the certificate creation and typically deducts the rebate value from your installation invoice. The ESS has been running since 2009 and ACPs are well-practised with commercial lighting upgrades. Underground car parks qualify as commercial premises.
VIC: Victorian Energy Upgrades (VEU)
VEU works similarly to ESS. An accredited provider creates Victorian Energy Efficiency Certificates (VEECs). The scheme covers lighting in commercial, industrial and common-area residential settings, which explicitly includes strata car parks. The property owner assigns the certificate rights to the installer in exchange for a point-of-sale discount.
SA: Retailer Energy Productivity Scheme (REPS)
REPS requires retailers to meet energy productivity obligations, which they do by buying certificates from verified projects. The process is similar to ESS and VEU. SA has the highest electricity tariff in Australia, so the combination of REPS certificates and operating savings produces the fastest payback of any state.
Important: Certificates can only be created for installations carried out by registered scheme participants. A standard electrician quoting on your car park may not be registered. Ask specifically whether the installer is accredited under your state scheme before proceeding. Non-registered installations cannot create certificates retrospectively.
Getting body corporate approval
Car park lighting is common property in virtually all strata-titled buildings. That means any upgrade requires a body corporate or owners corporation resolution. The good news is that the financial case for car park LEDs is strong enough to pass at most AGMs and EGMs without significant opposition, provided it is presented correctly.
Get two or three written quotes
Include a registered scheme participant in the quote list if your state has a rebate scheme. The difference between a registered and non-registered installer's net price after rebate can be $4,000-$6,000 on a typical car park job.
Prepare a one-page financial summary
State committee members are time-poor. A single page showing: current annual electricity cost for car park lighting, projected cost after upgrade, payback period, and lifetime saving over 10 years wins votes faster than a detailed technical spec. Use the LED Savings Calculator to generate a PDF version of this summary.
Confirm the funding mechanism
Most bodies corporate pay from the administrative or sinking fund. Upgrades under a certain threshold (varies by state legislation) may be approved by the committee without a general meeting. Check with your strata manager whether the quote falls under the threshold that triggers a full resolution vote.
Raise it as a motion at the next AGM
If a full resolution is required, include the financial summary and at least one quote as attachments to the meeting notice. Motions that include a clear payback period and a quote from a licensed installer pass significantly more often than those that don't.
Schedule the installation during low-traffic hours
In a residential building, 9am-3pm on a weekday is typically low-traffic for the car park. Notify residents in advance. A 50-fitting installation generally takes one day. Temporary lighting is rarely required at that ceiling height.
Fluorescent car parks: T8 battens in newer buildings
Not every car park has metal halide fittings. Many buildings constructed between 2000 and 2015 used fluorescent T8 battens in their car parks, typically 36W or 58W twin-tube fittings. These have lower wattage than metal halide but still run 7,300 hours a year, and most are overdue for replacement as the fluorescent tubes age.
A 36W twin-tube T8 batten running 7,300 hours consumes 263 kWh per year. A direct LED T8 retrofit batten at 18W consumes 131 kWh. On 50 fittings that is a saving of 6,550 kWh per year, less dramatic than the metal halide scenario but still a 2-3 year payback in most states and a direct driver swap with no rewiring required.
The more compelling case for fluorescent car parks is maintenance. T8 tubes are increasingly hard to source, lamp costs have risen, and older T8 ballasts are approaching end of life. A full fitting replacement to LED eliminates both the tube and ballast maintenance liability for 15 or more years.
What to specify
Underground car parks are a demanding environment. Fittings need to withstand vehicle exhaust fumes, occasional water ingress from ramp wash-down, impact from trolleys and low-clearance vehicles, and potential dust from concrete surfaces. Minimum specification requirements for any car park LED fitting:
Minimum specification: car park LED fittings
Calculating your own numbers
Every car park is different. The scenario above uses 50 × 250W fittings at 20 hours a day, but your building may have 28 fittings at 18 hours, or 80 fittings across two levels. The tariff your body corporate pays on the common area meter is also specific to your situation and may differ from the state averages used here.
The LED Savings Calculator at ledsavings.com.au is built specifically for commercial and common-area scenarios like this. Enter your fitting count, wattage, daily hours and current tariff, and it produces a payback period, annual saving, and lifetime saving figure. You can generate a white-label PDF report directly from the calculator, which is formatted to attach to a body corporate meeting motion.
Calculate your car park payback now
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