Loss trends reported by DEDDIE
Greek energy regulator RAAEY is preparing revised electricity-distribution loss coefficients following a report from network operator DEDDIE showing lower average losses during 2024. The update is intended to affect how much electricity suppliers must purchase to serve customers, while RAAEY is expected to scale back the size of the reductions compared with DEDDIE’s original proposal.
DEDDIE reported that average distribution losses fell from 11.2% to 10.81%. It proposed reducing the medium-voltage loss coefficient from 4.59% to 4.35%. It also proposed lowering the low-voltage coefficient from 16.19% to 15.15%.
Impact on supplier procurement volumes
Under the existing low-voltage coefficient, a supplier delivering 100 kWh to customers must purchase 116.19 kWh to cover recognised network losses. The proposed coefficient would reduce that requirement to 115.15 kWh. The change is described as small for an individual consumer but becomes more significant when applied across millions of metered accounts.
The proposal would lower recognised energy procurement by approximately 10.4 GWh for every 1 TWh of low-voltage consumption. At a wholesale price of €100/MWh, that equates to more than €1 million in avoided procurement cost before balancing and settlement effects.
Supplier concerns over settlement reconciliation
Suppliers have questioned the assumptions behind DEDDIE’s calculation, focusing on more than the headline coefficients. Their concern includes the possibility that provisional losses could be reconciled later against actual system data. Greece’s first-half 2022 experience is cited as an example, when differences between estimated and actual network losses resulted in additional charges of approximately €164 million over six months.
The episode has contributed to supplier caution about aggressive reductions that could later lead to large correction invoices. A coefficient that appears favourable initially can become a liquidity risk if retrospective settlement is delayed, volatile, or based on incomplete metering data.
Regulatory approach and data requirements
The regulatory decision reflects a trade-off between over- and under-recovery through loss coefficients. Keeping coefficients too high can overcharge suppliers and ultimately consumers for energy that is not lost, while reducing them too quickly can create under-recovery that reappears later as a settlement adjustment. RAAEY is expected to retain the methodology while moderating the scale of the proposed changes.
The quality of network data is central to the issue, with smart meters and more frequent settlement cited as factors that can narrow gaps between estimated and actual electricity flows. Improved detection of non-technical losses can also affect those gaps, while without such improvements loss coefficients remain partly an accounting mechanism for data uncertainty.
The source material distinguishes technical and non-technical losses in terms of system impact and response requirements. Lower technical losses are described as reducing procurement volumes, carbon exposure and costs passed through to consumers, while non-technical losses such as unmetered consumption and theft require enforcement and metering investment.
The proposed coefficients are described as providing modest immediate relief, with suppliers expected to assess the reform based on the stability of later settlements. The €164 million adjustment from 2022 remains the benchmark for risk relative to the smaller percentage reduction now under consideration.
