The activation, by electricity suppliers, of wholesale cost-related clauses included in their supply agreements is prompting significant retail increases, seen rising, compared to three months earlier, by 40 percent for the medium-voltage category and at least 33 percent for the low-voltage category.

Medium-voltage tariffs, previously at levels ranging between 64 and 65 euros per MWh, have reached 90 euros per MWh, a 40 percent increase, since the wholesale cost-related clauses were triggered by suppliers earlier this year, and are expected to rise further.

In the low-voltage category, concerning households, tariffs have increased from levels ranging between 70 and 90 euros per MWh, depending on the supplier and agreement, and will need to be raised to 120 euros per MWh for the recovery of increased wholesale costs.

Higher wholesale electricity prices have been attributed to a combination of factors, including higher CO2 emission right and natural gas prices, as well as a sharp rise in demand.

The situation is exacerbated during periods when RES output is subdued, prompting record-level price levels in the wholesale electricity market.

Last week, CO2 emission right prices set a new record of 58.25 euros per ton, up from 32 euros per ton in December, an 82 percent increase.

Natural gas prices have hit a 13-year high, TTF contracts reaching 29 euros per MW/h following levels of between 15 and 17 euros per MW/h in spring, a 93 percent increase. In June last year, gas prices had sunk to record-low levels of as low as 4.9 euros per MWh.

Last week, the average clearing price on the energy exchange ranged from 100.33 to 118.56 euros per MWh, up from 63.16 euros per MWh a month earlier.

In June, the average day-ahead market price on the energy exchange was 83.47 euros per MWh, more than double the level of 40.74 euros per MWh a year earlier.