How to reduce electricity losses in 0.4 kV networks

Losses in a 0.4 kV network have two parts: technical (heating of lines, cables and transformers) and non-technical (energy that reached a consumer but was not metered or not billed). They are reduced in different ways, so the first job is to separate them. Below is a work plan in which every step relies on data the distribution company already collects.

Step 1. Fix the metering records

While the records are wrong, the substation imbalance shows metering errors, not losses: a meter assigned to the wrong substation, an error in the registry, a meter that stopped reporting. Crews then look for irregularities where a record needs fixing (see Meter assigned to the wrong substation). GRID-IN reports for every substation whether there is enough data for a conclusion and what is wrong with it.

Step 2. Separate technical from non-technical losses

A 12 % imbalance on a short urban substation and on a long rural overhead line are different stories. On a short line technical losses are a small share of the imbalance and almost all the rest is non-technical. On a long overloaded line technical losses can be most of it. Without separating them, crews look for theft where there is none. Technical losses are calculated from the network diagram and the hourly load (see Technical loss calculation for 0.4 kV networks).

Step 3. Inspect a target list, not every consumer

Inspecting every consumer of a substation is expensive; random inspections find little. A target list says where to go and why: address, meter, type of irregularity, unmetered energy estimate and confirmation probability. Targets are grouped by location and ordered by return — first what gives the most kWh per trip (see How to detect energy theft from smart meter data).

Illustrative example. A district with 40 substations and 2,600 consumers. Inspecting everyone — about 2,600 visits. With a target list — 70 addresses in 12 location groups, two groups per crew day. The groups with the most unmetered energy per site go first.

Step 4. Record the outcome of every visit

For every target the crew records “confirmed”, “not confirmed” or “no access”. This shows what share of targets is confirmed, so managers judge the result by facts rather than promises. Targets without access stay open for the next visit.

Step 5. Cut technical losses

Technical losses grow with the square of the current: double the current on a section and its losses quadruple. So the measures that pay most are on overloaded sections:

rebalancing consumers across phases — with unbalanced phases losses are higher than with the same load spread evenly;
replacing conductors on sections loaded close to their rating;
moving the connection point of a large consumer closer to the substation.

GRID-IN shows the losses and loading of every overhead and cable section by hour, so it is clear where a measure pays most.

Step 6. Repeat the calculation regularly

Losses come back: new connections appear, meters fail, substation membership changes. New periods are added to the project manually or through the API, and only the substations that changed are recalculated. New targets appear in the list; resolved irregularities are shown as “earlier”.

What is needed?

At minimum, load profiles of consumer meters and of the substation input meter for the same period. A registry with addresses, billing, meter event logs and the network diagram widen the findings. No hardware has to be installed. Details — Data requirements.