Lighting rate comparison notes
A rate comparison shows how the same lighting kWh changes when two user-entered cents/kWh values are applied to the same energy amount.
Rate comparison sequence
Keep the energy amount fixed, then apply two rate values and read the spread.
- 1Enter one lighting kWh
Use the same energy amount in both cases.
- 2Add Rate A
Enter the first cents per kWh value.
- 3Add Rate B
Enter the second cents per kWh value.
- 4Read both costs
Compare the two computed AUD values.
- 5Read the difference
Use the absolute spread as the comparison number.
Application estimate fit
Match the search phrase to one lighting load, period and assumption set before reading the result.
| Search phrasing | Calculator case | Carry forward |
|---|---|---|
| Two-rate comparison | One lighting kWh figure with two cents/kWh values. | The lower cost and the difference between the two entries. |
| Sensitivity check | A quick way to see how much a lighting energy value moves across rates. | Keep the same kWh value in both sides of the comparison. |
| Tenant or site comparison | One energy amount tested against two assumptions from the same group. | Rate date, account basis and later annual note. |
| Bill line check | A useful screen when the same lighting kWh is being tested against two prices. | Keep the result inside the page as a bounded comparison. |
Reading the result
Each output belongs to a bounded lighting energy estimate and should travel with its assumptions.
| Output | Technical meaning | Review item |
|---|---|---|
| Cost difference | Absolute difference between the two entered costs. | Compare the same kWh against the same period. |
| Rate A cost | Lighting kWh multiplied by Rate A. | Write the rate value beside the result. |
| Rate B cost | Lighting kWh multiplied by Rate B. | Keep the two entered rates visible. |
| Lower entered cost | The smaller of the two computed costs. | This is a comparison only, not energy-plan guidance. |
Assumptions that stay visible
Small changes in load, hours, rate or factor can move the result, so the assumptions stay beside the number.
| Assumption | Why it matters | Where it belongs |
|---|---|---|
| Lighting kWh | The same energy amount must be compared on both sides. | Do not mix period lengths or control states. |
| Rate A and B | The two rates should be user-entered assumptions. | Record the chosen values beside the number. |
| Period | Monthly or annual context needs to stay consistent. | Keep the same basis for both costs. |
| Difference | The result is the absolute spread between the two computed costs. | Use it as a comparison note only. |
lighting energy amount before the number
A useful lighting rate comparison estimate begins with the exact lighting energy amount, not a whole-site average. The same building can include reception lights, display lights, warehouse aisles, amenity rooms and exterior signs that all run for different hours. Naming the group keeps the load, hours and money value tied to one visible lighting job.
That boundary also makes later revision easier. If the fittings, scene level or operating period changes, the row can be revised without rebuilding unrelated areas. Write the space name, fitting family and control group beside the result so another person can check the same case later.
Connected load remains the anchor
Energy and cost estimates move when connected load changes. Count the fittings or enter the load that belongs to the named group, then keep the wattage basis visible. Complete fitting input watts are stronger than a bare lamp value because drivers, control gear and luminaire packages can change the actual load.
The connected-load note does not prove the light level is suitable. A lower load can still be too dim, glary or uneven, while a higher load may support a harder task. Keep lux, beam, colour and measured-light pages nearby when the lighting quality also needs checking.
Hours carry much of the movement
A fixed kWh basis can move the annual result more than a small wattage change. Seven-day corridors, hospitality scenes, office task rows, seasonal stores and after-hours security lights may all have different operating patterns even when the fittings look similar.
Enter the hours for the same lighting group named in the result. If the group has a normal scene and an after-hours scene, split those cases rather than hiding both in one average. A tidy input line with hours, days and control state is easier to revise than a single unexplained total.
Controls change energy without changing installed load
The same load and period can reduce energy by shortening operating time or lowering average output. Occupancy sensing, daylight dimming, timeclocks, scene presets and holiday shutdowns all change the energy case while the installed wattage may remain the same.
Keep full connected load and controlled operation visible as different ideas. That separation lets a user compare the installed capacity, the normal operating case and the reduced-energy case without implying that the electrical installation has changed.
Rates and factors are user-entered assumptions
Two user-entered rate values belongs beside the result because it can change while the lighting kWh stays fixed. A rate comparison, carbon estimate or simple payback note is only as current as the entered cents per kWh, emissions factor or annual saving value.
For Australian lighting notes, keep the rate date, account basis or factor source in the project file if the result will be reused. This page keeps the arithmetic transparent; it does not choose an electricity plan, account structure, rebate or finance outcome.
Read comparisons as bounded arithmetic
Two cost cases for the same lighting kWh is helpful when the two cases share the same lighting group and schedule basis. Rate A and Rate B, old hours and new hours, or full output and dimmed output should describe the same load before the numbers are compared.
A comparison can show the size of a difference, but it does not decide whether the lighting change is appropriate. Light level, comfort, controls, maintenance access and site operating needs still need their own notes when they affect the decision.
Monthly, annual and period values are different
Monthly values are useful for a short period or a local cost note. Annual values are useful for longer operating schedules, carbon factors and simple payback. After-hours and shutdown values describe only the named period, not the whole lighting account.
Keep the period wording in the result. A monthly cost, an annual kWh value and a holiday shutdown saving should not be compared until the period, hours and days have been made consistent.
Australian energy estimate limits
lighting rate comparison pages on AuLumens are planning estimates for lighting load, kWh, user-entered cost rates, carbon factors or simple payback. They do not model demand items, metered account totals, rebates, tax treatment, electrical design, emergency lighting or certification.
It is not a tariff selector or account forecast. Keep account-specific charges, landlord agreements, emissions reporting basis and electrical installation details in the appropriate site file. The value of the lighting estimate is that it records the load, period and assumptions before those wider checks begin.
A concise calculation note
A readable note includes the lighting group, connected load, operating period, output state, user-entered rate or factor, and whether the result is monthly, annual or limited to a named period. For split cases, include both sides of the comparison.
Keep monthly running cost and annual energy pages nearby when the energy amount also needs a period note. That context makes the result practical. Another person can change the hours, revise the rate, adjust the control state or compare the result with measured energy data without guessing how the original number was produced.