Net electricity generated by Enel (TWh) 53.5 196.4 249.9 60.9 200.9 261.8
Electricity transported on the Enel distribution network (TWh) (1) 227.3 217.9 445.2 224.1 202.6 426.7
Electricity sold by Enel (TWh) 103.2 181.6 284.8 94.1 168.9 263.0
Gas sales to end users (billions of m3) 4.8 6.9 11.7 4.6 6.0 10.6
Employees at period-end (no.) 31,114 31,786 62,900 31,956 30,124 62,080

(1) The figure for 2016 reflects a more accurate measurement of amounts transported.

Net electricity generation by sourceNet electricity generated by Enel in 2017 decreased by 11.9 TWh on 2016 (-4.5%), due to the decrease in amounts generated in Italy (-7.4 TWh) and abroad (-4.5 TWh). The decline in generation in Italy is mainly attributable to the decrease in conventional thermal generation. Abroad, the reduction reflects the deconsolidation at the end of July of Slovenské elektrárne (-7.5 TWh), which more than offset the increase in generation in Spain and South America.

As regards the technology mix, the change is mainly attributable to a decrease in nuclear generation (-7.0 TWh), coal- and oil-fired generation (-4.7 TWh) and hydroelectric generation (-4.7 TWh). These effects were only partly offset by an increase in natural gas generation (+4.1 TWh) and solar generation (+1.4 TWh).

Finally, 33% of the electricity generated by Enel in 2017 came from renewable sources.

Electricity transported on the Enel distribution network in 2017 amounted to 445.2 TWh, up 18.5 TWh (+4.3%), essentially reflecting the acquisition of Enel Distribuição Goiás (formerly CELG-D).

Electricity sold by EnelElectricity sold by Enel in 2017 amounted to 284.8 TWh, up 21.8 TWh (+8.3%) on the previous year, reflecting the increase in amounts sold on markets in Italy (+9.1 TWh, with the largest increase coming in the business customer segment), South America (+11.6 TWh) and Spain (+3.0 TWh), only partly offset by a decrease in amounts sold in Romania, France and Slovakia following the Group’s exit from those markets.

At December 31, 2017, Enel Group employees numbered 62,900 (an increase of 820 on the end of 2016). The rise reflects the net balance of new hires and terminations (-2,111) and the change in the scope of consolidation (+2,931 overall), which included the acquisition of Demand Energy and EnerNOC in North America and Enel Distribuição Goiás (formerly CELG-D) in Brazil.

The following table reports the employee workforce by geographical area.

 at Dec. 31, 2017at Dec. 31, 2016
Italy 28,684 29,321
Iberia 9,711 9,695
South America 13,903 12,979
Europe and North Africa 5,733 5,858
North and Central America 2,050 891
Sub-Saharan Africa and Asia 198 185
Other 2,621 3,151
Total 62,900 62,080