Tag: maximum demand charges

Why Your Industrial Electricity Bill Keeps Rising (When Production Hasn’t)

Short answer: an industrial bill rises mainly through four controllable items — maximum demand charges created by short load peaks, power factor penalties from inadequate or failed capacitor banks, energy wasted by inefficient motors, lighting and idle equipment, and harmonic distortion that quietly increases losses. Tariff changes usually explain less of the increase than plant teams assume. The useful first step is to stop reading the bill as a single number. An industrial tariff is several different charges with different causes, and each one has a different fix. Read the Bill as Four Separate Problems Bill Component What Drives It The Engineering Fix Maximum demand charge The highest short-interval demand recorded in the billing period Demand monitoring and controller, load staggering, soft starting, storage for peaks Power factor penalty Low PF from motors, welding sets, idle transformers, failed capacitors APFC with correctly sized steps, detuned reactors where harmonics exist Energy (kWh) charge Inefficient motors, pumps, compressors, old lighting, idle running Efficient equipment, VFDs on variable loads, LED retrofit, sub-metering Time-of-day differential Heavy load scheduled in the costliest hours Load scheduling, shifting batch processes, captive solar during day Maximum Demand: A 15-Minute Mistake That Bills All Month Demand charges are based on the peak recorded over a short interval, so a single coincidence — two compressors, a furnace and the chiller all starting together after a break — can set the charge for the entire month even though average load never approached it. Fixing this rarely requires capital equipment. It requires visibility (a demand controller with alarms), a starting sequence for large loads, and discipline about what is allowed to start simultaneously. Where peaks are unavoidable, battery storage sized for peak shaving can be cheaper than the demand penalty and far cheaper than a connection upgrade. Power Factor: Check Whether the Capacitors Are Actually Working Many plants have an APFC panel that stopped doing its job years ago — blown capacitor units, failed contactors, a controller in manual, or capacitors destroyed by harmonic currents from the drives installed after the panel was built. The symptoms are a steady penalty and nobody noticing because the panel is physically present. Audit it: measured PF at the incomer, step-by-step capacitor health check, contactor and fuse condition, and a harmonic measurement to decide whether detuned reactors are required. Harmonics: The Loss Nobody Sees on the Bill Line Harmonic currents do not appear as a billed item, but they raise losses in transformers, cables and neutrals, shorten capacitor life, and cause nuisance tripping that costs production. In plants with substantial drive, rectifier or UPS load, a harmonic survey at the main LT bus is the fastest way to discover whether apparent inefficiency is actually distortion. Where the Energy Is Actually Going Compressed air: leaks and over-pressurisation are usually the single largest avoidable loss in a plant Pumps and fans: throttled flow where a VFD would match output to demand Motors: oversized or rewound repeatedly, running well below efficient loading Lighting: legacy fittings and no zoning or occupancy control in low-traffic areas Idle running: equipment left energised across breaks and shift changes Transformers: lightly loaded units kept energised, carrying no-load losses around the clock You cannot manage any of this without sub-metering. A plant with a single incomer meter has one number and no information; feeder-level metering turns the bill into a map. Where Captive Solar Fits For a plant with daytime operation, captive rooftop solar displaces energy at the point of use and the economics depend on how much generation coincides with load. It reduces the kWh charge, not the demand charge — which is why solar is usually combined with demand management rather than treated as a substitute for it. VTPL executes electrical upgrades that address these items directly — APFC and harmonic mitigation, metering and distribution works, lighting retrofits, solar power plants, and EV and storage infrastructure — backed by 33+ years of electrical EPC experience and 1,000+ projects delivered across 19+ states. Frequently Asked Questions What is maximum demand charge? A charge based on the highest demand recorded over a short measurement interval during the billing period, independent of how long that peak lasted — which is why brief coincident starting of large loads can be expensive. How do I avoid a power factor penalty? Maintain power factor close to the level the tariff rewards, using an automatic power factor correction panel sized in appropriate steps, with detuned reactors where harmonic distortion is present, and a maintenance routine that verifies the capacitors are still healthy. Why is my power factor low despite having capacitors? Usually because capacitor units have failed, contactors or fuses are open, the controller is in manual, or harmonic currents have damaged the bank — the panel looks installed but is no longer correcting. Does solar reduce demand charges? Not directly. Solar reduces energy consumption charges when generation coincides with load. Demand charges are addressed by demand management or by storage sized for peak shaving. Where should an energy reduction programme start? With measurement: feeder-level sub-metering and a demand profile. Without that data, savings projects are guesses, and results cannot be verified afterwards. VTPL delivers power distribution, APFC and metering upgrades and captive solar projects for industrial clients. Request a project consultation →