How does the workbook work out the demand charge?

Billing demand is the largest of the month's metered peak, the ratchet share times the highest peak in the look-back months, and the minimum share times contract demand. The expected charge is billing demand times the rate per kW times the share charged, plus fixed demand fees. For 920 kW at 18.50 per kW, 100% charged and 450 in fixed fees, that is 17,470, the same as the Utility Demand Charge calculator.

What is a demand ratchet and what does it cost?

A ratchet bills you for at least a share of your highest recent peak, even in months when your own peak is lower. In the example, two furnaces cold-started together in January 2025 and set a 2,780 kW peak; with an 80% ratchet over 11 months, billing demand stayed at 2,224 kW for the next 11 bills while the plant actually peaked near 2,000 kW, which added 35,220.50 in demand charges.

How is load factor calculated?

Load factor is kWh divided by peak kW times the hours in the billing period. A 31-day bill of 925,410 kWh with a 2,310 kW peak has a load factor of 925,410 / (2,310 x 31 x 24) = 53.8%. A higher load factor means the same energy with a lower peak, and so lower demand charges. Over several months the workbook divides total kWh by the sum of each month's peak times hours.

My tariff has a contract demand, not a ratchet. Does this still work?

Yes. Set the ratchet to 0%, enter the contract (sanctioned) demand and the minimum share billed, for example 75%. Billing demand is then the larger of the metered peak and 75% of the contract demand, the rule used in many Indian industrial tariffs and similar to agreed-capacity charges elsewhere. Check your own tariff for its exact rule.

Why does the Check column flag a bill?

When the demand charge on the bill differs from the tariff calculation by more than your tolerance (2% in the example), or when a load factor is above 100%, a month appears twice or the month is not the first day. In the example, the March 2026 bill charges 31,234.81 against an expected 29,522.50, a variance of 1,712.31 or 5.8%, so it is flagged as a question for the utility.

Is energy intensity a fair comparison between months?

It is kWh divided by good output, so it moves with efficiency but also with product mix and volume: fixed loads such as lighting and air compressors are spread over fewer units in a short month. In the example, August's shutdown month shows about 1,546 kWh/t against about 1,430 kWh/t in a normal month. Compare like months, or read intensity together with production.

Energy and Sustainability

Energy Use and Demand Charge Tracker Excel Template

Log each month's electricity bill and sub-meter readings, and see what you paid for energy and for peak demand, what a ratchet carried forward, whether the bill matches your tariff, and how much energy each unit of output took.

Overview

This energy tracker is a working Excel workbook for plant managers, energy managers and maintenance engineers who receive a large electricity bill every month and want to know what drives it. It ships with two years of example bills for a fictional aluminium die-casting foundry, so the dashboard and charts are populated the moment you open it; replace the example rows with your own bills and everything recalculates.

An industrial bill has two big parts: energy, charged per kWh, and demand, charged per kW of the highest short-interval demand in the month. Many tariffs also bill at least a share of the highest peak of the previous months (a ratchet) or of the contract demand. The workbook applies those rules from Setup to every bill: billing demand is the largest of the month's peak, the ratchet floor and the contract minimum, and the expected demand charge is billing demand times rate times the share charged, plus fixed fees, the same formula as the Utility Demand Charge calculator. The difference from the bill is checked against your tolerance, and the cost of past peaks is shown on its own.

In practice, enter each bill when it arrives and look at the two charts on the dashboard's first page: the bill by component shows how much of the cost is demand, and peak against billing demand shows the months when an old peak, not this month's load, set the bill. Load factor and kWh per unit of output show whether the plant is using energy better, and the sub-meter view shows where the energy goes and how much is unmetered.

What this template includes

Monthly Bills table: days billed, kWh, peak kW, energy, demand and other charges, and the month's production, one row per bill
Per-bill total, load factor, blended cost per kWh, energy intensity and cost per unit of output, with an intensity status against your target
Billing demand worked out from your tariff: the larger of the month's peak, a ratchet share of the highest peak in the look-back months, and a minimum share of contract demand
Expected demand charge and the variance against the bill; a Check column that flags a demand charge outside your tolerance, duplicate months and impossible load factors
Paid for past peaks: what the ratchet or contract minimum added to each bill
Sub-meters table (kWh per end use per month) with each meter's share of the bill and the unmetered remainder
Dashboard for any 12 months: cost, demand share, ratchet cost, highest peak, intensity, load factor, blended cost and MWh, with four native charts (bill by component, peak against billing demand, intensity against target, energy by end use)
Method sheet with every formula, and a Verify sheet that re-checks the formulas against an independent reference, including the Utility Demand Charge calculator's example (Self-check: PASS)

Suggested use case

Use it to review the electricity bill every month, to show management what peak demand really costs before a load-shifting or furnace-scheduling project, and to track kWh per unit of output for an energy management programme.

How to use it

On Setup, enter your plant name, currency, output unit, intensity and load factor targets, and the demand rules from your tariff: rate per kW, ratchet share and look-back, contract demand minimum and fixed fees.
On Monthly Bills, add one row per bill on the first day of the month it covers, with days, kWh, peak kW, the three charge lines and the month's production.
Read the Check column and query the utility about any bill flagged as above or below the tariff.
On Sub-meters, add each meter's monthly kWh if you have sub-metering.
Open the Dashboard; set '12 months ending' to compare any year with the last.

Frequently Asked Questions

How does the workbook work out the demand charge?: Billing demand is the largest of the month's metered peak, the ratchet share times the highest peak in the look-back months, and the minimum share times contract demand. The expected charge is billing demand times the rate per kW times the share charged, plus fixed demand fees. For 920 kW at 18.50 per kW, 100% charged and 450 in fixed fees, that is 17,470, the same as the Utility Demand Charge calculator.
What is a demand ratchet and what does it cost?: A ratchet bills you for at least a share of your highest recent peak, even in months when your own peak is lower. In the example, two furnaces cold-started together in January 2025 and set a 2,780 kW peak; with an 80% ratchet over 11 months, billing demand stayed at 2,224 kW for the next 11 bills while the plant actually peaked near 2,000 kW, which added 35,220.50 in demand charges.
How is load factor calculated?: Load factor is kWh divided by peak kW times the hours in the billing period. A 31-day bill of 925,410 kWh with a 2,310 kW peak has a load factor of 925,410 / (2,310 x 31 x 24) = 53.8%. A higher load factor means the same energy with a lower peak, and so lower demand charges. Over several months the workbook divides total kWh by the sum of each month's peak times hours.
My tariff has a contract demand, not a ratchet. Does this still work?: Yes. Set the ratchet to 0%, enter the contract (sanctioned) demand and the minimum share billed, for example 75%. Billing demand is then the larger of the metered peak and 75% of the contract demand, the rule used in many Indian industrial tariffs and similar to agreed-capacity charges elsewhere. Check your own tariff for its exact rule.
Why does the Check column flag a bill?: When the demand charge on the bill differs from the tariff calculation by more than your tolerance (2% in the example), or when a load factor is above 100%, a month appears twice or the month is not the first day. In the example, the March 2026 bill charges 31,234.81 against an expected 29,522.50, a variance of 1,712.31 or 5.8%, so it is flagged as a question for the utility.
Is energy intensity a fair comparison between months?: It is kWh divided by good output, so it moves with efficiency but also with product mix and volume: fixed loads such as lighting and air compressors are spread over fewer units in a short month. In the example, August's shutdown month shows about 1,546 kWh/t against about 1,430 kWh/t in a normal month. Compare like months, or read intensity together with production.