Substation energy imbalance: where it comes from and how to find where energy is lost

Q: What makes up the imbalance?

CauseWhat to do about it Technical lossesalways present; calculate them from the network diagram and reduce them by network work: phase rebalancing, replacing overloaded sections Unmetered consumption (theft)a visit to the address, a report, back-billing Unauthorised consumptiona visit, then a contract or disconnection Faulty metermeter replacement or repair Meter not reportingrestore communication; until then its consumption looks like losses Meter assigned to the wrong substationfix the balance group membership in the records Error in the metering registryfix the record; no visit needed

The substation imbalance is the difference between the energy supplied at the input and the sum metered at consumers. The metering system reports it as one number per substation. But one number hides different causes, and each is fixed differently. GRID-IN splits the imbalance by cause and takes it down to addresses.

Illustrative example. Substation input — 52,000 kWh a month, consumers — 45,300. Imbalance — 6,700 kWh (13 %). Of this: technical losses from the network diagram — 1,900; a meter that did not report for half the month — 900; two theft targets with estimates of ≈ 2,400 and 1,100; the remaining 400 kWh are within metering accuracy.

What makes up the imbalance?

Cause	What to do about it
Technical losses	always present; calculate them from the network diagram and reduce them by network work: phase rebalancing, replacing overloaded sections
Unmetered consumption (theft)	a visit to the address, a report, back-billing
Unauthorised consumption	a visit, then a contract or disconnection
Faulty meter	meter replacement or repair
Meter not reporting	restore communication; until then its consumption looks like losses
Meter assigned to the wrong substation	fix the balance group membership in the records
Error in the metering registry	fix the record; no visit needed

Why is the imbalance percentage not enough?

The same 13 % can mean one large consumer bypassing the meter, an error in the metering registry, or a long overloaded line. The first needs a visit to an address, the second a registry fix, the third network work. Until the cause is named, a visit is a guess.

What does a negative imbalance mean?

Consumers “used” more than was supplied at the input. Energy does not appear from nowhere, so this is a metering error, not losses. Such an imbalance means fixing the metering first and only then looking for losses.

What does GRID-IN do?

reports for every substation whether there is enough data for a conclusion and what is wrong with it;
detects non-technical losses with several independent methods;
calculates the technical losses of every section from the network diagram;
merges the findings into one target list with address, type of irregularity, energy estimate and confirmation probability.

The substation imbalance ends up split into technical losses, specific addresses and metering errors. More — Energy theft, Meters of another substation, Technical losses.

What imbalance is normal?

There is no single number: the acceptable level depends on line length and cross-section, load and meter accuracy class. So compare the imbalance not with a norm but with the calculated technical losses of that substation. Everything above them and above metering accuracy is non-technical losses or metering errors. An imbalance “within the norm” does not mean there is no theft: it can hide behind low technical losses.

What is needed?

Load profiles of consumer meters and of the substation input meter for the same period. To split technical from non-technical losses — the 0.4 kV network diagram. Details — Data requirements.