Greek energy regulator RAAEY is preparing revised electricity-distribution loss coefficients after network operator DEDDIE reported a reduction in average losses during 2024. The changes should lower the amount of electricity suppliers must purchase to serve customers, although the regulator is expected to adopt smaller reductions than DEDDIE originally proposed.
Average distribution losses declined from 11.2 per cent to 10.81 per cent. DEDDIE proposed reducing the medium-voltage loss coefficient from 4.59 per cent to 4.35 per cent and the low-voltage coefficient from 16.19 per cent to 15.15 per cent.
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 appears small at the level of an individual consumer, but it becomes financially material when applied across millions of metered accounts.
For every 1 TWh of low-voltage consumption, the proposed reduction would lower recognised energy procurement by approximately 10.4 GWh. At a wholesale price of €100/MWh, that represents more than €1 million of avoided procurement cost before balancing and settlement effects.
Suppliers have nevertheless questioned the assumptions behind DEDDIE’s calculation. Their concern is not limited to the headline coefficient but extends to the risk that provisional losses will later be reconciled against actual system data. Greece experienced a severe example in the first half of 2022, when differences between estimated and actual network losses generated additional charges of approximately €164 million over six months.
That experience has made suppliers wary of aggressive reductions that may later produce large correction invoices. A coefficient that is initially favourable can become a liquidity risk when retrospective settlement is delayed, volatile or based on incomplete metering data.
The regulatory decision therefore involves a trade-off. Keeping coefficients too high overcharges suppliers and ultimately consumers for energy that is not lost. Reducing them too quickly can create an under-recovery that reappears later as a large 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. Smart meters, more frequent settlement and improved detection of non-technical losses can narrow the gap between estimated and actual electricity flows. Without those improvements, loss coefficients remain partly an accounting mechanism for data uncertainty.
Lower technical losses would be a genuine efficiency gain for the Greek electricity system. They would reduce procurement volumes, carbon exposure and the cost passed through to consumers. Non-technical losses, including unmetered consumption and theft, require a different response involving enforcement and metering investment.
The proposed coefficients provide modest immediate relief, but suppliers will judge the reform by the stability of later settlements. The €164 million adjustment from 2022 remains the more important benchmark for risk than the small percentage reduction now under consideration.
