Net electricity generation

Milions of kWh
Other sources2527(2)-7.4%
Total net generation74,19378,618(4,425)-5.6%

In 2018, net electricity generation totaled 74,193 million kWh, a reduction of 4,425 million kWh from 2017. This decrease is reflected in the lower thermal and nuclear production, which was partly offset by the increase in hydroelectric and wind production, and in the reduction in demand for electricity.

Contribution to gross thermal generation

Milions of kWh
Fuel oil5,7708.9%6,3198.6%(549)-8.7%
Natural gas6,90710.6%9,75013.2%(2,843)-29.2%
Nuclear fue25,03138.5%27,54237.4%(2,511)-9.1%
Other fuels3,9476.1%3,8655.3%822.1%

Gross thermal generation in 2018 totaled 64,995 million kWh, a decrease of 8,637 million kWh compared with the previous year. With regard to the mix used, there was a decrease across all types of fuels, especially in natural gas and coal.

Net efficient generation capacity

at Dec. 31, 2018at Dec. 31, 20172018-2017
Thermal plants12,87413,030(156)-1.2%
Nuclear plants3,3183,318--
Hydroelectric plants4,7614,75290.2%
Wind farms1,7501,6181328.2%
Total net efficient capacity22,71722,732(15)-0.1%

Net efficient capacity in 2018 amounted to 22,717 MW, a decrease of 15 MW compared with the previous year, mainly due to the disposal of the combined-cycle and coal/ fuel-oil plants (or parts of those plants) at Teruel, Compostilla and Alcúdia, which was largely offset by an increase in installed capacity in wind farms following the acquisition of Parques Eólicos Gestinver.

Electricity distribution and transport networks

High-voltage lines at year end (km)19,62519,560650.3%
Medium-voltage lines at year end (km)118,531117,8866450.5%
Low-voltage lines at year end (km)181,457180,3361,1210.6%
Total electricity distribution network (km)319,613317,7821,8310.6%
Electricity transported on Enel’s distribution network (millions of kWh) (1)124,714126,360(1,646)-1.3%

(1) The figure for 2017 reflects a more accurate measurement of amounts transported.

Electricity transported in 2018 totaled 124,714 million kWh, a decrease of 1,646 million kWh, which is essentially in line with the trend in demand.

Electricity sales

Milioni di kWh
Free market76,77283,036(6,264)-7.5%
Regulated market12,86713,477(610)-4.5%
Total electricity sold by Enel89,63996,513(6,874)-7.7%

Electricity sales to end users in 2018 totaled 89,639 million kWh, a decrease of 6,874 million kWh compared with 2017.


Milions of euro
 20182017 Change 
Gross operating margin3,5583,573-15-0.4%
Operating income1,7241,842-118-6.4%
Capital expenditure1,4331,10532829.7%

The following tables break down performance by type of business in 2018.


Milions of euro
Thermal Generation and Trading6,3196,233861.4%
Infrastructure and Networks2,6712,786(115)-4.1%
Enel Green Power71649721944.1%
End-user markets14,92015,798(878)-5.6%
Enel X247-247-
Eliminations and adjustments(5,895)(5,795)(100)1.7%

Revenue in 2018 decreased by €502 million due to:

  • a decrease of €878 million in revenue on End-user markets due to lower volumes sold both on the regulated market (-€123 million) and on the free market (-€747 million), as well as to a reduction in sales of value-added services of €235 million, which were transferred to the 60 Annual Report 2018 new Enel X Business Line. These reductions were partly offset by an increase of €229 million in revenue from gas commodity sales, which is reflected in the increase in quantities sold;
  • an increase of €86 million in revenue from Thermal Generation and Trading, mainly related to the increase in gas sales, largely to the electricity distribution companies in the country and which are therefore also reflected in eliminations. Accompanying these effects were an increase in reimbursements for costs incurred in the generation of electricity in the extra-peninsular area and the capital gain generated by the contribution in kind to the capital increase of Front Marítim del Besòs SL. The reduction in revenue from the sale of electricity partially offset these positive effects;
  • an increase of €219 million in revenue from generation by the Enel Green Power Business Line, connected with greater quantities sold, which were consistent with the increase in production from hydroelectric sources, due above all to greater water availability compared with 2017, as well as to changes in the scope of consolidation due to the acquisitions of Parques Eólicos Gestinver and other smaller wind power companies. Here, too, a portion of this revenue was from electricity marketing companies and is therefore reflected in eliminations;
  • a decrease of €115 million in revenue from Infrastructure and Networks operations, essentially due to lower fees for connections to the grid as a result of the application of IFRS 15;
  • an increase of €247 million in the revenue of Enel X, mainly related to sales of value-added services, which in 2017 were the prerogative of marketing companies.

Gross operating margin

Milions of euro
Thermal Generation and Trading425783(358)-45.7%
Infrastructure and Networks1,9652,086(121)-5.8%
Enel Green Power36119916281.4%
End-user markets67646720944.8%
Enel X51-51-

The gross operating margin amounted to €3,558 million, a decrease of €15 million compared with 2017, reflecting:

  • a decrease in the margin on Infrastructure and Networks operations, in the amount of €121 million, which was affected by the aforementioned decrease in revenue for connections accompanied by a slight increase in costs for services and materials;
  • an increase of €209 million in gross operating margin on End-user markets, essentially due to the significant decrease in the costs for provisioning and transport of energy, which more than compensated for the sharp reduction in revenue, to which we can add a reduction in costs for trading fees negotiated following the application of IFRS 15 (€70 million) and costs for value-added services attributed to the Enel X Business Line starting from 2018;
  • a decrease of €358 million in gross operating margin recognized in Thermal Generation and Trading, which reflected the effect of the reimbursement of costs for the “bono social” in 2017 (€222 million) and an increase in costs for the provisioning of fuel; 
  • an increase of €162 million in the margin on generation by the Enel Green Power Business Line, where the higher revenue mentioned above was partially offset by the increase in operating costs, particularly for water diversion fees and charges for access to the transmission network (in line with the greater quantities produced);
  • an increase of €51 million in revenue from value-added services related to the new Enel X Business Line.

Operating income

Milions of euro
Thermal Generation and Trading(274)191(465)-
Infrastructure and Networks1,2201,367(147)-10.8%
Enel Green Power20812196-
End-user markets49428620872.7%
Enel X37-37-

Operating income in 2018, including depreciation, amortization and impairment losses in the amount of €1,834 million (€1,731 million in 2017), came to €1,724 million, a decrease of €118 million compared with 2017 due, in addition to the effects mentioned above, to the impairment of certain assets at the Alcúdia power plant (€82 million), and an increase in depreciation and amortization, particularly for contract costs in application of IFRS 15 (€54 million).

Capital expenditure

Milioni di euro
Thermal Generation and Trading3452955016.9%
Infrastructure and Networks668657111.7%
Enel Green Power24665181-
End-user markets107555294.5%
Enel X39-39-

Capital expenditure came to €1,433 million, up €328 million year on year. More specifically, capital expenditure in 2018 mainly concerned the construction of new wind farms and photovoltaic plants following the awarding of projects in 2017. In addition, there was work on the distribution network for substations and transformers, work on the line and replacement of the metering devices and the capitalization of contract costs (€70 million) in enduser markets. Greater capital expenditure by the Thermal Generation and Trading Business Line included the nuclear plants at Ascó, Vandellòs and Almaraz