Auxiliary power is the electricity a plant spends on itself — the pumps, fans, mills, compressors and cooling systems that keep generation running. It typically runs 6 to 10 percent of gross output, and every fraction of a percent is real money burned before a single kilowatt reaches the grid. The problem: when a bearing drags or an impeller fouls, that motor quietly pulls more power for months, buried inside total station service where no one is looking. OxMaint AI maintenance management software links each auxiliary load to its asset and its work-order history, so a rising draw becomes a diagnosed fault — and a fix.
Power Generation · BOP Efficiency · Auxiliary Consumption Analytics
Power Plant Auxiliary Power Consumption Maintenance Analytics
Degrading equipment doesn't announce itself — it just draws more current. OxMaint AI ties every auxiliary motor to its condition and its maintenance record, so a climbing kW reading points straight to the failing bearing, fouled impeller or misaligned coupling behind it. Parasitic load stops hiding inside station service, and efficiency losses become work orders.
1 Meter the load
2 Spot the drift
3 Diagnose the fault
4 Work order & verify
6–10%
of gross generation spent on auxiliary loads
Months
a degrading motor can draw extra before anyone notices
5 systems
pumps · fans · mills · compressors · cooling
Per asset
every kW tied to a condition and a work-order trail
Why Auxiliary Losses Stay Invisible
Auxiliary consumption is usually bundled into one station-service number. That single figure can't tell you a boiler feed pump is running 4% hot because its bearing is dragging — the extra draw is lost in the total. Without per-asset submetering tied to maintenance history, mechanical wear adds parasitic load silently, and the plant pays for it every hour. Start free and break auxiliary load down to the asset in OxMaint AI.
BUNDLED STATION SERVICE
Where the Loss Hides
- One total number — no per-asset visibility
- Degrading bearings add draw for months, unseen
- Fouled impellers and misalignment blamed on "load"
- No link between a kW rise and a maintenance cause
- Efficiency drifts down with nothing to act on
ANALYTICS IN OXMAINT AI
Where the Loss Surfaces
- Each auxiliary load tracked against its own asset
- A rising draw flagged the moment it drifts from baseline
- The reading points to a specific mechanical fault
- Every anomaly becomes a diagnosed, ranked work order
- Efficiency recovered fix by fix, and proven
The Five Auxiliary Systems — and What Inflates Each
Auxiliary load isn't evenly spread. A handful of systems dominate the draw, and each has its own maintenance failure modes that quietly push consumption up. Here's where the power goes, and the wear that inflates it. Book a demo to map these loads to your own asset register.
~28%Pumps
Boiler feed & condensate
The single largest auxiliary consumer. Worn wear-rings, internal recirculation and impeller erosion force the pump to work harder for the same flow.
Watch for: rising kW at steady flow, bearing temperature, seal leakage
~24%Fans
ID, FD & PA draft fans
Blade fouling, damper leakage and bearing wear raise the power drawn to move the same air. Imbalance shows up as vibration long before failure.
Watch for: vibration trend, current vs. flow, bearing condition
~14%Mills
Pulverizers & coal handling
Worn grinding elements and classifier issues drive specific power per tonne up. Conveyor drive drag and misalignment add avoidable load.
Watch for: kWh per tonne, motor current, gearbox condition
VariesCompressors
Instrument & service air
Air leaks, fouled coolers and worn valves make a compressor cycle longer and load more often — one of the most overlooked parasitic drains.
Watch for: load/unload cycles, discharge temperature, leak rate
~19% / ~9%Cooling
Circulating water pumps & tower fans
Circ-water pumps and cooling-tower fans together move huge volumes. Fouled fills, worn fan blades and pump wear degrade heat rejection and raise draw.
Watch for: approach temperature, pump kW, fan vibration
Shares are indicative
Typical proportions of auxiliary load for a coal-fired unit — your split depends on plant type, fuel and configuration. The method is the same: meter each, trend each, fix each.
A Motor Drawing 5% More Isn't "Just Load." It's a Fault You Can Fix.
Every one of these systems drifts upward as it wears — and bundled metering hides it. OxMaint AI links the reading to the asset to the work order, so parasitic load becomes a diagnosis, not a mystery on the monthly heat-rate report.
How Maintenance Condition Turns Into Wasted Power
The link between a worn part and a higher electricity bill is direct and physical. Each failure mode below forces a motor to draw more current for the same work — and each is catchable before it costs a full year of waste. Sign up free and trend draw-versus-condition on your critical drives.
Dragging Bearings
Friction from wear, poor lubrication or misalignment adds a constant power penalty and heat.
Fouled Impellers
Deposits and erosion drop hydraulic efficiency, so the pump draws more to hold flow.
Misaligned Couplings
Misalignment wastes energy as vibration and heat, and accelerates bearing and seal wear.
Blade & Fill Fouling
Fouled fan blades and tower fills force more power to move the same air or reject the same heat.
Air & Damper Leakage
Compressed-air leaks and leaking dampers make equipment run longer and load more often.
Worn Grinding Elements
Degraded mill internals raise the specific power needed to grind each tonne of fuel.
From Rising Draw to Recovered Efficiency
Catching parasitic load is a loop, not a one-off audit: measure, spot the drift, find the cause, fix it, and confirm the draw came back down. This is the analytics workflow OxMaint AI runs on every auxiliary asset. Book a demo to run this loop on your top consumers.
Step 1
Meter per asset — capture power draw against each auxiliary load, not one bundled station-service total.
Step 2
Trend vs. baseline — compare current draw to the asset's healthy baseline at the same operating point and flag the drift.
Step 3
Diagnose the cause — pair the kW rise with vibration, temperature and history to name the fault — bearing, impeller, alignment.
Step 4
Raise the work order — the anomaly becomes a ranked, assigned work order against that exact asset, with the data attached.
Step 5
Verify the recovery — after the fix, confirm draw returned to baseline — proof the efficiency loss is actually gone.
What OxMaint AI Analytics Give You
Turning auxiliary consumption into a maintenance lever takes more than a meter — it takes the software layer that ties every reading to condition, history and action. Start free and see per-asset auxiliary analytics end to end.
Per-Asset Draw Tracking
Auxiliary consumption broken out by asset, so no motor's parasitic load hides in the total.
Baseline Drift Alerts
A rising draw against a healthy baseline triggers an alert before it's a full year of waste.
Draw-to-Fault Diagnosis
kW trends paired with vibration, temperature and history to point at the real mechanical cause.
Condition-Based Work Orders
Anomalies become ranked work orders on the exact asset — no manual re-keying of readings.
Efficiency Verification
Post-repair draw checked against baseline, so a recovered loss is proven, not assumed.
Auxiliary Load History
Every asset's draw and repair record in one trail — the basis for reliability and BOP-efficiency reporting.
Frequently Asked Questions
What is auxiliary power consumption in a power plant?
How does maintenance affect auxiliary consumption?
Worn bearings, fouled impellers and misaligned couplings force motors to draw more current for the same work, adding parasitic load that persists until the fault is found and fixed.
Book a demo of draw-to-fault diagnosis.
Which auxiliary systems use the most power?
Boiler feed pumps and draft fans lead, followed by circulating water pumps and pulverizer drives, with cooling-tower fans and compressors adding more — each with its own wear-driven losses.
Sign up free and rank your own consumers.
Why doesn't the plant notice the extra draw?
How does OxMaint AI turn a kW rise into action?
Stop Paying for Wear You Can't See.
Auxiliary power is the one efficiency loss that hides in plain sight — a worn bearing or fouled impeller quietly billing you every hour. OxMaint AI maintenance management software ties every kW to its asset and its fix, so parasitic load becomes a work order and BOP efficiency becomes something you manage, not just measure.
