Non renewable electricity generation

Non-renewable production structure by power station type and by autonomous communities

Utilisation rate of peninsular thermal power stations

The production of mainland coal-fired power plants recorded a historic low in 2023

In the Spanish electricity system, the production of coal-fired power plants in 2023 fell by 50.1 % compared to the previous year, maintaining its reduced presence in the mix, with a share of only 1.5 % of total domestic generation.

In 2023, mainland coal-fired plants generated 3,811 GWh, which is 50.4 % less than the previous year; this is the lowest value recorded. During 2023, monthly coal-fired generation was lower than that in the same months of the previous year, with December seeing the steepest monthly decline, with a fall of 69.4 %. In addition, January, April, May, June, July, November and December recorded the lowest monthly coal-fired monthly production rates to date.

The decarbonisation targets set by the European Union to reduce CO2 emissions have meant that coal-fired production, which is more polluting than other technologies, remains a small part of the energy mix, registering an all-time low share of 1.5 % of total generation in 2023.

The utilisation rate (the ratio between actual production and the production that could have been achieved if the power stations had operated at their rated power for the entire time they were available) of coal-fired power stations in 2023 stood at 26.9 %, down from the 69.8 % registered the previous year.

In the Balearic Islands, the closure of sets 1 and 2 of the Alcudia plant and the limitation of the operating hours of sets 3 and 4 meant that in 2023, coal-fired generation fell by 23.1 % compared to the previous year, and it only took place in the months of June, July, and August.

In 2023, combined cycle was the third largest source of domestic generation

In line with total non-renewable generation, in 2023, combined cycle production in the Spanish electricity system dropped by 32.4 % compared to the previous year and occupied the third position in the national generation mix, with a share of 17.3 % of the total, 7.4 percentage points less than in 2022, when it became the leading technology with a share of 24.7 %.

In 2023, the production of mainland combined cycle plants was 35.1 % lower than in 2022, with the greatest declines recorded during the third and fourth quarters of the year. During 2023, mainland monthly combined cycle generation was lower than that of the same months of the previous year, with January seeing the steepest monthly decline, with a fall of 57.8 %.

The lower rate of annual production in the mainland combined cycle stations has resulted in a 7.6 percentage points decrease in their representation in the energy mix, reaching a share of 15.5 % in the mainland structure in 2023, compared to 23.1 % in 2022, when it held the leading position in the mainland electricity mix. Despite this decline in annual production, in June 2023, combined cycle plants constituted the main source of generation in the mainland production structure, with a share of 20.1 %.

The utilisation rate of mainland combined cycle production in 2023 was 21.9 % (34.1 % in 2022).

In 2023, the combined cycle stations of the Balearic Islands electricity system generated 3,071,232 MWh, 22.9 % less than in 2022, which registered the highest level of production since 2007. For the fourth consecutive year, this technology has represented the main source of generation in the Balearic Islands mix, with a share of 67.2 % in the production structure.

In the Canary Islands electricity system, combined cycle power stations produced 3.0 % more in 2023 than in 2022, reaching an all-time high of 3,696,718 MWh. Furthermore, combined cycle stations were once again, and for the thirteenth consecutive year, the leading technology in the Canary Islands generation mix, with a share of 42.2 %. In October 2023, the combined cycle plants reached the highest production value ever recorded to date, with 385,374 MWh.

Among non-renewable energy technologies, nuclear generated a total of 54,041 GWh in 2021, 3.1 % less than the previous year. This drop occurred mainly during the first and last quarters of 2021, when nuclear production fell by 6.2 % and 15.3 %, respectively. In February, nuclear generation decreased by 10.8 % due to the operational unavailability of the Trillo power station, and in March the decrease was 6.6 %, coinciding with the unavailability of the Almaraz II power station, which began work on its 26th refuelling. The sharpest decreases in nuclear production occurred in November (23.2 %) and December (25.6 %) due to the refuelling stoppages at the Ascó 1, Cofrentes, and Almaraz I power stations.

As a result of these lower production levels, nuclear power stations have become the second largest source of generation on the Spanish peninsula for the first time after ten consecutive years of being the leading source in the peninsular mix (in 2013, they shared the lead with wind power). In 2021, nuclear reached an overall share of 21.9 % in peninsular generation (23.3 % in 2020).

The utilisation rate (the ratio between actual production and the production that could have been achieved if the power stations had operated at their rated power for the entire time they were available) was 97.7 %.

Among non-renewable energy technologies, nuclear generated a total of 54,276 GWh in 2023, 3.0 % less than the previous year. In May, nuclear generation fell by 8.0 % to fall again in June by 10.1 % due to the unavailability of the Almaraz I plant, caused by refuelling work from 17 April to 20 May, Ascó I, which began refuelling on 29 April and ended on 14 June, and Trillo, from 24 May to 23 June. In October, the nuclear production rate fell by 7.0 %, and in November by 10.1 %, due to the unavailability of the Cofrentes plant, which carried out a scheduled refuelling outage from 6 October to 12 November, and Ascó II from 22 October to 10 December.

As a result, in 2023, nuclear power plants were the second largest source of mainland generation, with a share of 21.4 % of the mainland mix, a very similar share to that of 2022, when they were ranked third, with 21.3 %. During July, August and September, nuclear was the leading technology in the mainland generation mix.

The utilisation rate was 96.4 %, slightly lower than in 2022, when it was 97.7 %.

2023 sees a historic low in CO2 equivalent emissions from domestic electricity generation.

During 2023, there has been a decrease in CO2 equivalent emissions from domestic electricity generation, reaching 32.0 million tonnes of CO2 equivalent, the lowest value on record, which is 27.9 % lower than the figure for 2021, and 71.2 % lower than the emissions recorded in 2007.

The increase in renewable generation that has taken place in the national electricity system in 2023 has favoured a lower use of technologies based on fossil fuels, especially coal-fired and combined cycle plants, which explains the reduction in CO2 equivalent emissions from with these technologies by 49.8 % and 31.2 %, respectively.

CO2 Emissions and CO2 equivalent emission factors associated with electricity generation