Until now we've treated the chiller plant as a machine. Here we look at the other end of the wire — the electricity supply from the grid. The attached MSEDCL bill is for a connection literally named "Retail-1 Chiller, Retail Mall", so what the chiller plant does shows up directly on this bill.
// Source: MSEDCL HT-II bill, Consumer 000XXX000, Bill month JUL. Figures in Indian format (lakh / crore).
The association at a glance
Two supply sources feed one metering point that powers the chiller plant.
This month, in numbers
JUL · the whole bill is essentially the cost of running this plant.
Total bill
₹1.33 Cr
₹1,32,54,460
Demand charge
₹21.3 L
3,549 kVA × ₹600
Energy charge
₹51.0 L
kVAh × ₹14.03
Total drawal
11.25 L
kWh this month
Power factor
0.996
near-perfect
Contract demand
4,732
kVA contracted
Peak demand
3,149
kVA highest recorded
Renewable
8.99 L
kWh injected (OA)
Key fields extracted from the bill
Connection
ConsumerMall
Consumer no.000XXX000
ServiceRetail-1 Chiller
Tariff158 · HT-II
Voltage22 kV (HT)
OA typePartial Open Access
Connected since10-Feb-2017
Demand & energy
Contract demand4,732 kVA
Billed demand3,549 kVA
Highest recorded3,149 kVA
Total drawal11,24,956 kWh
kVAh billed3,63,446
Reactive (RKVAH)1,01,453
Power factor0.996
Why each field matters for the chiller plant
The plant is typically 40–60% of a mall's electricity, so these levers move real money.
Demand charges are billed on your peak kVA, not energy — here ₹600 per kVA. The chiller compressors, pumps and tower fans are the biggest contributors to that peak. If several chillers stage up together on a hot afternoon, demand spikes; exceed the contract demand and you pay a penalty. Smart staging, avoiding simultaneous compressor starts, and peak-shaving keep billed demand down — trimming the peak by even 200 kVA saves ~₹1.2 lakh every month.
Energy billed in kVAh + Power Factor (0.996)
Note the energy charge (₹51 L) is on kVAh (apparent energy), not pure kWh. Motors draw reactive power, so a poor power factor inflates kVAh and the bill. This plant runs a near-perfect 0.996 PF — capacitor banks and VFDs are doing their job. Let PF slip to 0.90 and the same cooling would bill ~10% more kVAh.
Time-of-Day (TOD) tariff — slots A / B / C / D
Energy is priced differently by time slot (this bill: A 7,302 · B 15,957 · C 1,60,904 · D 1,77,830 units). Running chillers harder in cheap off-peak hours, night pre-cooling, or thermal storage shifts load off the expensive slots — a prime target for AI load-shifting.
Total kWh & chiller efficiency (kW/ton)
The 11.25 lakh units drawn are dominated by the chiller plant. Every improvement in kW/ton (raising CHWS, tower optimization, staging, pump trimming, healthy ΔT — everything in this suite) scales directly onto this energy charge.
Open Access (solar 4,400 kVA + wind 2,550 kVA)
The plant's large, predictable load makes it worth buying cheaper renewable power on Open Access instead of full grid tariff. Solar/wind is injected and banked (8.99 lakh kWh injected, 7.63 lakh offset against drawal). The trade-off: open-access power carries wheeling, transmission and cross-subsidy charges (₹40 L, bill part B) to use the grid as a delivery network.
kW · kVAR · kVA · PF · APFC — the power triangle
Why the same cooling can cost different amounts: it's about how the current is made up.
kW — real (active) power
Useful work — compressing refrigerant, pumping water, spinning fans, making cooling. The only part that does a job; this is what registers as kWh.
kVAR — reactive power
Sustains the magnetic fields inside motor windings & transformers. Does no useful work — it sloshes to-and-fro — but inductive motors (compressors, pumps, fans) can't run without it.
kVA — apparent power
The total burden the cables, transformer and utility must be sized for. The vector sum: kVA² = kW² + kVAR². Demand is billed in kVA.
PF — power factor
PF = kW ÷ kVA (cos θ). The fraction of the burden doing useful work. 1.0 is perfect; 0.8 means a fifth of capacity is carrying reactive power that does nothing.
Try it: how power factor inflates the burden
Power factor0.85
Useful (kW)
3,500
Burden (kVA)
4,118
Reactive (kVAR)
2,170
Current vs PF 1.0
+18%
Demand charge
₹24.7 L
vs PF 1.0
+₹3.7 L
Useful work (kW) is held fixed at 3,500. As power factor falls, kVAR and kVA balloon — the plant draws more current and pays more demand charge for the same cooling. Slide to 0.996 (this plant's actual PF) and the burden collapses back onto the useful work.
APFC — Automatic Power Factor Correction
An APFC panel is a capacitor bank plus a controller that automatically switches capacitors in and out to supply the kVAR locally. The motors draw their magnetizing current from the capacitors instead of the grid, so PF rises toward 1.0 and kVA (and current) shrink. On this bill, PF = 0.996 with RKVAH of 1,01,453 logged — clear evidence a working APFC is installed and keeping the apparent power (the kVAh you're billed on) almost equal to the real work.
Which one drives high electricity consumption?
kW drives the real consumption (the kWh you fundamentally pay for) — cut it with efficiency (kW/ton, staging, ΔT). kVAR does no useful work and isn't billed as real energy, but it inflates kVA and current, raising billed demand (kVA), billed energy (kVAh) and cable losses when PF is low. So: lower kW = less genuine consumption; higher PF (via APFC) = less avoidable inflation of the bill.
Where the ₹1.33 crore goes
Grouped by major component (approx).
Energy 38%
Duty 24%
OA transport 20%
Demand 16%
Energy charges ₹51.0 L Electricity duty ₹31.7 L OA wheeling/transmission/CSS ₹26.1 L Demand charges ₹21.3 L TOD energy charge ₹2.9 L
Line item
Amount
Lever
Energy charges (MSEDCL, kVAh @ ₹14.03)
₹50,99,147
controllable
Demand charges (3,549 kVA @ ₹600)
₹21,29,400
controllable
TOD tariff energy charge
₹2,86,261
controllable
Electricity duty (MSEDCL + OA)
₹31,74,872
statutory
OA cross-subsidy surcharge
₹8,75,204
OA-driven
OA transmission charges
₹8,73,272
OA-driven
Wheeling charges (MSEDCL + OA)
₹8,35,811
OA-driven
Tax on sale + FAC credit + operating + rebates (net)
₹-19,503
statutory
Total current bill
₹1,32,54,460
The takeaway
Roughly three-quarters of this bill is influenced by how the chiller plant runs — energy (efficiency), demand (staging & peak), TOD (load-shifting) and power factor. The rest — electricity duty, taxes, and the wheeling / transmission / cross-subsidy charges that come with the Open Access arrangement — is largely fixed or policy-driven. So the optimization work in the rest of this suite isn't just about machine health; it lands straight on this ₹1.33-crore monthly invoice. The chiller plant is the load; the electricity board is the meter that prices every decision it makes.