Two cement plants can use the same kilowatt-hours and still pay very different bills. The difference sits in the tariff: when the energy was drawn, how high the peak reached and how well power was used. Reading a bill line by line shows what was paid, but not why. Joining the tariff schedule to interval consumption and to what the plant was making shows the reasons. That is where savings are found without touching output. Teams who want that join built for them can ask iFactory AI how tariffs and plant data are combined.
Cement Plant Electricity Tariff and Time-of-Use Cost Analysis
Turn a tariff schedule into a cost map. iFactory AI joins interval consumption, demand charges and production context, so every energy review starts from facts.
Tariff Schedule Inputs
Every analysis starts with a handful of inputs. Collect these from the tariff order and the latest bill, and write each one down once.
Here is a sample day used through this page. Rates and hours are illustrative, so replace them with your own schedule.
Interval Consumption: Where the Megawatts Go
Cement load is large and fairly steady, so the shape is flatter than in most plants. Each bar below is a two-hour average, coloured by the tariff band it falls in.
Off-peak: about 18 MW
The kiln line, fans and coolers carry the night. Mills run at a lower share in this sample.
Normal: about 20 MW
Mills and packing add load across the working day, with the highest draw in the middle hours.
Peak: about 21 MW
The evening peak sits on top of the highest rate, which is the most expensive place for load.
The Daily Energy Bill, Band by Band
Multiply energy in each band by its rate, then add. Here is the sample day worked out in full.
| Band | Hours | Average MW | Energy kWh | Rate per kWh | Cost in Units |
|---|---|---|---|---|---|
| Off-peak | 8 | 18 | 144,000 | 6 | 864,000 |
| Normal | 12 | 20 | 240,000 | 8 | 1,920,000 |
| Peak | 4 | 21 | 84,000 | 10 | 840,000 |
| Whole day | 24 | 19.5 | 468,000 | 7.74 average | 3,624,000 |
Turn Your Tariff into a Cost Map
Book a 30-minute session and iFactory AI will load a tariff schedule against realistic cement interval data, then show where each unit of cost comes from.
Demand Charges: One Quarter Hour Sets the Month
Energy is billed by the kilowatt-hour. Demand is billed on the highest average draw in a single interval, so one brief spike can set the charge for the whole month.
Ratchet clauses
Some tariffs bill a share of the highest demand from the past 11 or 12 months. One bad interval then keeps costing for a year.
Coincident or not
A non-coincident charge uses your own peak whenever it happens. A coincident charge uses your draw during the grid's peak hours.
Worked on our sample
A 22,000 kW peak at 300 units per kW is 6,600,000. Trimming the peak by 1,500 kW saves 450,000 a month, illustrative figures only.
Shift and Process Context: What Can Really Move
A tariff only matters if load can respond. Process context separates loads that can move from loads that must stay put.
| Process Area | Typical Flexibility | What Limits It | Check First |
|---|---|---|---|
| Kiln line and fans | Very low | Continuous burning, stable operation | Avoid any schedule change |
| Raw mills | Medium | Raw meal silo level, kiln feed needs | Silo levels at shift change |
| Cement mills | Medium to high | Cement silo levels, product plan, dispatch | Order book and silo stock |
| Packing and loading | Low to medium | Truck arrivals and customer hours | Dispatch schedule |
| Compressed air and pumping | Medium | Tank and reservoir sizes | Pressure and level limits |
Know who is on duty
A mill start at night needs a crew and supervisor cover. Label shifts in the data so a move is realistic.
Respect planned stops
Planned work removes load for a reason. Mark it so a lower bill is not mistaken for a saving.
Compare like with like
Finer cement uses more power per tonne. Report kWh per tonne by cement type, not as one average.
Scenario Comparison: Three Ways to Run the Same Day
Compare scenarios on the same output. Only the timing of load changes, so the comparison stays fair.
Business as usual
The sample day as it is. Daily energy cost is 3,624,000 units.
Move one mill out of peak
About 24,000 kWh moves from the peak band to off-peak. Daily cost falls to 3,528,000 units.
B plus an earlier mill start
Another 12,000 kWh moves from normal to off-peak. Daily cost falls to 3,504,000 units.
Small share, large scale
A three percent day looks modest, yet it repeats every day of the year. Always show the annual view beside the daily one.
Watch the demand charge
A cheaper band is no gain if the move creates a new maximum demand interval. Check both together.
Test the constraints
A schedule that empties a silo is not a saving. Every scenario needs the same output and stock limits.
Power Factor and Fixed Charges
Two smaller lines complete the bill. Both are easy to overlook and quick to check.
How efficiently power is used
A low value means the utility delivers more apparent power than you use, so many tariffs add a penalty. Large motors are a common cause, and capacitor banks can correct it. A published bill example shows 0.87 triggering a penalty.
What you pay whatever you use
Customer and metering fees are the same each period. Keep them separate from energy and demand so per-tonne analysis is not distorted.
The Assumption Log
Every analysis rests on assumptions. Write them down so a reviewer can challenge each one and the result can be repeated next quarter.
| Assumption | Value Used | Source | Review When |
|---|---|---|---|
| Tariff version | Order date and reference | Utility tariff order | Any new order is issued |
| Time bands and rates | Hours and rate per band | Latest bill | Season or band changes |
| Demand interval and ratchet | 15 or 30 minutes, ratchet share | Tariff order | Contract renewal |
| Meter boundary | Billing meter or plant incomer | Single line diagram | Meter change |
| Production context | Tonnes by cement type | Production records | Product mix changes |
| Shift limits | Silo levels, crew cover | Operations team | Plant plan changes |
Common Tariff Analysis Mistakes
Most errors come from habits. Pair each with its fix and the review stays honest.
What iFactory AI Adds to Tariff Analysis
iFactory AI is smart manufacturing and industrial software that brings meter, SCADA and historian data into one energy view for cement teams. Tour the energy cost dashboards on sample cement data to see it in action.
A 30-Day Plan to Start
A month is enough to load a tariff, join the data and agree a first scenario for one plant.
Cost per Tonne: The Number Finance Will Ask For
A total bill hides production changes. Dividing by tonnes makes months, plants and scenarios comparable. The sample day assumes 5,000 tonnes of cement.
| Scenario | Daily Cost in Units | Energy kWh | kWh per Tonne | Cost per Tonne |
|---|---|---|---|---|
| A: business as usual | 3,624,000 | 468,000 | 93.6 | 724.8 |
| B: mill out of peak | 3,528,000 | 468,000 | 93.6 | 705.6 |
| C: B plus earlier start | 3,504,000 | 468,000 | 93.6 | 700.8 |
Energy per tonne stays put
Shifting load changes cost, not energy. If kWh per tonne moves, something else changed, such as product mix or efficiency.
Cost per tonne falls
Timing alone lowers cost per tonne from 724.8 to 700.8 in this sample. It is the cleanest way to show the saving.
Report both together
Show kWh per tonne and cost per tonne side by side so efficiency gains and timing gains are not confused.
From One Day to One Year
A single day proves the method. The annual view shows whether it is worth the effort, and which season matters most.
One Cost Story, Four Readers
The same analysis serves different people. Give each reader the view that answers their question first.
Bill Check: Five Tests Before You Trust the Model
Run these tests on one past bill. Each one catches a different kind of error before it reaches a decision.
Questions to Ask Before Moving Any Load
Existing records answer most of these. Each question points to the record that settles it.
Plain-Language Glossary
Shared words keep the review short. Agree these terms once and use them in every report.
Frequently Asked Questions
What is time-of-use cost analysis for a cement plant?
It prices each interval of consumption at the rate for its time band, then adds demand and power factor charges. The result shows where cost comes from and which loads could move.
Why is the demand charge so sensitive?
Because one interval sets it, so a short spike can cost a whole month, or longer under a ratchet. See a demand spike traced in a live demo on sample data. Each reduced kilowatt saves every month.
Can a cement plant shift load without hurting output?
Often, within limits. Mills and some utilities have room, while the kiln line does not. Silo levels and dispatch plans set the boundary. Ask support how limits are built into scenarios for your site.
Which data do we need to begin?
The tariff order, recent bills and interval data from the billing or plant meters. Production records by cement type make the cost per tonne meaningful.
How do we know the analysis is right?
Rebuild a past bill from interval data and the tariff, then compare it with the real one. Book time to test a bill reconciliation with your team. A close match builds trust.
Know What Every Hour of Power Costs
iFactory AI joins tariff schedules, interval consumption and production context, then shows demand charges, time-of-use cost and scenarios for every cement plant. Book a walkthrough on your own tariff.
