Reactive energy and reactive charges: limits and early warning

You don't just pay for “active energy” (kWh) in your electricity bill; The grid also imposes fees or penalties for transporting and managing reactive power (kVAr). Reactive energy is the energy component that feeds the magnetic field of inductive loads, especially motors, transformers and coils. If not measured, the "reactive cost" item noticed after the invoice is issued can reach tens of thousands of lira annually in most industrial facilities.

Active and reactive power: difference between kWh and kVArh

Active energy (kWh) is the energy that does work, is measured and billed from the tariff — production line, lighting, heating. Reactive energy (kVArh) is related to power quality and grid load; It does not do any work on its own, but it strains transformers and lines. The distribution company limits the subscriber's reactive/active ratio; If the limit is exceeded, a reactive charge (penalty) is written on the invoice.

Inductive and capacitive reactive

• Inductive reactive (Ri): Motors, transformers, welding machines, reactors — consume magnetic field; appears on the invoice as “inductive” or “Ri”.
• Capacitive reactive (Rc): Overcompensation or capacitive loads — appears as “capacitive” or “Rc” on the invoice.
• Ideal situation: cos φ (power factor) close to the active power; Both Ri and Rc must remain below the limits.

Capacitor, shunt reactor and coil

Coil (inductor): Resists change in electric current; motor windings and transformers show coil behavior → produce inductive reactive. Capacitor: The element that stores current; Capacitor banks (compensation) are installed in installations to compensate for the inductive reactive — reducing the reactive penalty, improving cos φ. Shunt reactor: It is generally used to extinguish excessive capacitive reagent at the solar power plant/network point or to balance the line voltage; Incorrect setting may still result in a penalty. Compensation project is not “install a capacitor and done”; kVAr should be calculated according to the load profile and OSOS data.

Installed power and contract power

Installed power (kW): Total technical capacity of transformers and consumption points in the facility — “hardware” upper limit. Contract power (kW): The power agreed with the distribution company and used in the demand/power fee calculation — generally around 60% of the installed power is requested (varies depending on the facility).

The value taken as basis in calculating reactive penalty limits and exemption is the contract power (“power” / guc_kw in the invoice and OSOS records). Installed power is a reference not only for capacity planning but also for contract power application.

Below 9 kW exemption and limit table

Subscribers with a contractual power of 9 kW and below are considered exempt from the reactive penalty (EXEMPT_POWER_LIMIT = 9 kW in the ENOPTIMAL OSOS module). Above 9 kW, the permissible reactive/active ratios vary depending on the contract power.

In the invoice archive and invoice_installations records, limit percentages are also stored according to the contract power (guc_kw) read from the invoice; A threshold of 33% / 20% is used for power below 50 kW, and 20% / 15% for 50 kW and above. A 30 kW threshold applies to live OSOS alerts — the two sources may result from different legislative interpretations; base the critical decision on the cap line on your official invoice.

What is the reactive charge on the invoice?

The amount calculated for the inductive and/or capacitive reactive amount exceeding the limit appears in the "reactive energy fee", "reactive consumption" or similar lines on the invoice. The calculation logic is summarized as: excess kVArh × unit reactive energy cost. Unit price is updated every period; In the ENOPTIMAL backend, it is kept in the ReactiveEnergyCost field (kurus/kVArh) of the EnergyTariff table and this current value is used in OSOS penalty estimates.

EnergyTariff.ReactiveEnergyFee

ReactiveEnergyFee in backend/Models/EnergyTariff.cs is updated with periodic tariff records. OssosDashboardHandler retrieves the last valid positive reactive cost from the database; Thus, incorrect penalty projections are not made with “last year's price”. Reactive items can also be cross-checked with this tariff in the invoice verification module.

How is punishment created? (Example logic)

• Period active consumption: 100,000 kWh, inductive reactive: 40,000 kVArh → rate 40%.
• Contract power 25 kW (< 30): inductive limit 33% → 7% points exceeded.
• Based on the excess kVArh, the TL penalty is calculated with the current Reactive Energy Cost.
• Separate limit (20%) and separate overshoot are checked for the capacitive side.
• Post-compensation deduction (discount) lines can be shown separately on the invoice.

What should you do?

• Monitor 15 min/hour Ri and Rc from OSOS or meter; Intervene in the middle of the month.
• Verify contract strength with invoice and subscription document.
• Resize the compensation (capacitor) and, if necessary, the shunt reactor according to the load profile.
• Prioritize reactive penalty history by ranking by facility.
• Ensure EnergyTariff updates are committed to the platform.

Conclusion

Reactive energy is a hidden cost item in industry; Without 9 kW exemption, 30 kW threshold limits and current reactive unit price information, it would be expensive to find out after the invoice. ENOPTIMAL consumption management module operationalizes this risk with OSOS integration, reactive penalty warnings and tariff table.