321.9 Terawatt-hour: A year of energy

What is dispatching?

It is a term that at first seems complex, but is simple to comprehend and of the utmost importance: it is Terna's balanced management of electricity supply and demand.

Electricity cannot be stored (at least, not in large amounts). The amount of energy required by consumers, families and companies must therefore be produced on a minute by minute basis, and their transmission managed on the national electricity grid. The aim is to ensure that supply and demand are always balanced. This ensures the continuity, security and adequacy of service provision.

Dispatching lies at the heart of the electricity system, and each year Terna publishes the data on the main parameters relating to the management of the Italian electricity system and service quality.

Looking at the data and contrasting it with that of the last year, we can get an idea of the direction the country is moving in and the challenges that await it.

From an energy transition perspective, energy production from renewable sources is growing, now standing at 112.8 TWh. The figure is now equal to 35% of total electricity demand, with an increase of 3% compared to 32% in 2017. Italy has one of the highest average coverage from renewable sources in Europe, but is also in line with the decarbonisation objectives set forth in national and international plans.

This increase is entirely due to hydroelectric sources. Specifically, detail by source shows a considerable increase in hydroelectric production (+ 31% to 49.2 TWh) in 2018, which mitigates the decline in other renewable sources such as photovoltaic (-4.7% to 22.9 TWh), wind power (-1.4% at 17.3 TWh), biomass (-0.8% at 17.7 TWh) and geothermal (-1.9% at 5.7 TWh), in addition to thermoelectric production (-7,6% to 185 TWh).

Why this strong change in hydroelectric energy production? 2018 was a year with higher rainfall than 2017, which was a year with more drought: as hydroelectric production is linked to natural sources, if there is no rain then less energy is produced. Usually a rainy year is also more cloudy (hence the reduction in photovoltaic production).

In 2018 Italy’s electricity demand reached 321.9 TWh, up +0.4% compared to 2017, and was met for 86%by domestic production for consumption, down 1.7% (which amounted to 278.0 TWh), and for the remaining 14% from imports from abroad (which saw a sharp increase of 16% to 43.9 TWh). The increase in imports (which have now come back into line with Italy’s average value) is linked above all to the reduced availability of exported energy from neighbouring countries during 2017, also due to colder temperatures in the winter of 2016- 2017.

So which are the days of the year when less energy is consumed? Easter Sunday and Monday, which consequently are also days of the year with greater coverage from renewable sources. The record in electricity demand for 2018 was set on 1 August at 16:00 with 57.8 GW, 2,5% more than the 2017 peak. Until about ten years ago, peak consumption during the year was always in winter (between January and February), given the energy used for heating systems across Italy. With gradual climate change and the ever-stronger summer heat, the period of greatest demand is shifting to late July-early August due to the now widespread use of air conditioners (the all-time record for daily consumption is 60.5 GW, from the end of July 2015).

The figures register the installed capacity of renewable energy sources at 57,033 MW, up + 2%, with 22,862 MW hydroelectric, 20,047 MW solar (+445 MW), 10,205 MW wind power (+475 MW), 3,439 MW bioenergies (+137 MW) and 870 MW from geothermal sources (unchanged). Such trend is associated with the installation of a large number of small plants (mainly domestic photovoltaic plants), which continues to grow, also due to governmental decisions to encourage the use of these sources. According to the trends forecast in the integrated National Energy and Climate Plan (NECP), in 2030 about 40GW more in installed capacity from solar and wind sources is expected to be in use than today; the value currently stands at 30GW.