How the numbers are calculated

Sunrise & sunset

Uses the NOAA Solar Position Algorithm. For each month's mid-point day, the model computes: fractional year, equation of time, solar declination, hour angle, solar noon, sunrise, and sunset. The zenith angle of 90.833° accounts for atmospheric refraction and the sun's apparent diameter. DST-aware: switches between the Winter and Summer UTC offset on the real changeover dates for each place, using this year’s calendar: the last Sunday of March to the last Sunday of October in Europe and Lebanon, the second Sunday of March to the first Sunday of November in the United States and Canada, the first Sunday of October to the first Sunday of April in the Australian states that observe it, the last Sunday of September to the first Sunday of April in New Zealand, and, in Chile, the Sunday after the first Saturday of September to the Sunday after the first Saturday of April (clocks change at midnight at the end of that Saturday). A month that contains a changeover is split by days: its waste is worked out on both clocks and weighted by the number of days on each, so the figures match local clock time year-round. The calculators place the clock changes in the current calendar year, so a figure can move from one year to the next with the same inputs: usually by under half a percent, and by up to about 2% for a fleet that is entirely on timers.

Timer waste

Wasted hours per day count only hours inside the timer window (Timer ON to Timer OFF; an OFF time after midnight counts as the next day). Evening: max(0, min(Sunset, Timer OFF) − Timer ON) × 24; a timer that comes on after sunset adds nothing. Morning, when Timer OFF is before noon and after sunrise: max(0, Timer OFF − max(Sunrise, Timer ON)) × 24; a timer that is off before sunrise adds nothing. No hour outside the timer window is counted, so the waste never exceeds what the timer burns. Multiply by days in month × timer faces for inventory hours, then × kW × rate for cost.

Photocell excess

Photocell-controlled faces stay lit from sunset to sunrise. Excess hours measure the time from Timer OFF (or sunset, if later) to next sunrise: (Sunrise − max(Timer OFF, Sunset)) × 24, across midnight. This captures hours photocell faces burn that timer faces do not.

Unsold face burn

Unsold faces are split proportionally by inventory mix (timer % vs. photocell %). Timer burn = Timer ON→OFF daily hours. Photocell burn = average sunset→sunrise hours across 12 months. Adjusted by how often unsold faces are already switched off (the answer to “How often do you turn off your unsold faces?”).

Why can the headline be larger at 80% occupancy than at 100%? At 100% occupancy every face is sold, so the saving comes only from trimming each face's schedule to the actual sunset. Once some faces are unsold, the calculator also counts the energy those faces use when they are lit with no advertiser, which is a saving you are not capturing yet. This is why leaving unsold faces on shows a larger number than 100% occupancy: the extra amount is the opportunity from switching them off, and it shrinks as you switch them off more often.

Energy conversion

kWh = Hours × (Wattage ÷ 1000)
Cost = kWh × Utility Rate
All wattage is the total per-face value entered in inputs.

Total annual savings

Sum of Solar Waste savings (timer + photocell illumination waste eliminated) plus Unsold Burn savings (energy saved by properly managing unsold inventory illumination). Reflects the total efficiency opportunity across the entire fleet.

CO₂ emissions avoided

Electricity is converted to emissions with a location-based grid factor: kg CO₂e = kWh × grid factor. US selections use EPA eGRID 2023 state averages; Australian selections use 2025 NGA state/territory factors. Other countries use the documented national generation average.

Campaign device usage

The Static Efficiency Calculator follows the GMSF physical OOH Device Usage step: placements × days × daily kWh × allocation × grid factor. It reports current and controlled operational electricity and emissions. This is one campaign stage, not a whole-campaign footprint.

Data quality

Each report identifies whether device electricity is modeled, based on a company or regional average, or site-metered. Location factors are labeled as state or national averages, and user-entered campaign scale is shown separately from defaults.

Service calls and nightly light inspections

Service visits per structure per year (typically 4.5) for timer resets, inspections and repairs. Remote monitoring and control resolves 50% of them (timer resets, light checks, wasted trips), so 50% are counted as avoided; the other 50% still need a visit (failed drivers, storm damage, vandalism). With a contractor, the price per visit already includes travel, so the distance to the structures is used only for the light-inspection driving and the travel and CO₂ avoided. Timer resets are 2.5 a year per timer structure where the clocks change (two changes plus about half a visit for drift and power cuts) and 0.5 where they do not; crews do them board after board on a route. The Static calculator covers static (lit) boards only; digital boards are modeled in the separate Digital Efficiency Calculator. A contractor's call is priced at the price entered. With your own crews, a trip costs crew × hourly pay × (1 h on site + driving at 30 mph) + miles × (diesel at 15 mpg + $0.70 vehicle cost) (the vehicle cost excludes fuel: AAA’s 2026 figure for a half-ton pickup driven 20,000 miles a year, the latest available, used for every country), with hourly pay = monthly pay × the country's employer cost factor ÷ 173 h. The factor adds the employer's social contributions and legally required extra pay (such as 13th-month salary) to gross pay, and ranges from 1.018 to 1.54 depending on the country. The distance between boards on a route is estimated from how densely they sit: boards spread around the base, hop ≈ 0.7124 × √(area ÷ boards). Nightly light inspections (light runs) are replaced completely by monitoring: the technician's pay (all of it when light inspections are their only duty, otherwise the share of working time entered) plus the vehicle, up to 150 miles a night. Technician pay and diesel defaults are researched by country and can be changed.

Fewer service trips

Travel avoided equals the miles of the trips avoided: round trips for single visits, the hop plus a share of the drive out for route visits, and the light-run miles. The editable CO₂ default reflects an EPA typical passenger vehicle; NOx and PM2.5 use older EPA in-use averages and are explicitly treated as legacy screening values. External reporting should use route- and fleet-specific MOVES, California EMFAC, or UK EFT outputs. Health outcomes require local dispersion and exposure modeling.

Digital screens: service calls and revenue protected

The Digital Efficiency Calculator counts two things. Site visits avoided: you enter the screen issues that would each need a site visit (per screen, per month); Outdoorlink’s remote power cycle resolves 70% of them, so site visits avoided a year = screens × issues per screen a month × 12 × 70%, each priced at the contractor’s price per site visit or, with your own technicians, as one dedicated round trip (the same single-trip cost as above).

Revenue protected: each screen carries 8 ad slots at a time and operates 18 hours a day (6:00 to 24:00), 547.5 hours in an average month (18 × 365 ÷ 12 days), so revenue per screen hour = price per ad slot a month × 8 ÷ 547.5. An issue that needs a site visit leaves the screen dark for 4 hours; a remote power cycle restores it in 5 minutes. Only the issues fixed remotely count, and only sold slots earn: revenue protected = issues fixed remotely × revenue per screen hour × (4 h − 5 min) × occupancy rate. Uptime is measured over the 6,570 operating hours a year; the typical 99.5% contract uptime guarantee is shown for context and is not part of any total.