Comparison between model output and actual 2015 values

2.3.2 Comparison between model output and actual 2015

Figure2.9:EnergyflowsinItalyintheyear2015.AllvaluesareinTWh.ThemethodologyusedtotreatthedataisdocumentedinAppendixA.

Table 2.7: Model validation: model outputs vs. actual 2015 values for the Italian energy system. Actual values for the Italian energy system are taken from [156] unless otherwise indicated. More details provided in Sec. A.8 in Appendix A.

Actual 2015 LP ∆ ∆rel Units

Gasoline 95.24 97.65 2.41 2.53 % TWh

Diesel 302.06 302.70 0.64 0.21 % TWh

- Diesel for Mobility 280.17 291.05 10.88 3.88 % TWh Light Fuel Oil 14.86 14.79 -0.07 -0.47 % TWh

Coal 144.29 145.88 1.59 1.11 % TWh

- Coal for Elec. 114.00 114.97 0.97 0.85 % TWh

Primary NG 617.39 602.69 -14.7 -2.38 % TWh

Energy - NG for Mobility 31.56 31.25 -0.31 -0.99 % TWh

Consumption - NG for Elec. 196.24 189.41 -6.83 -3.48 % TWh

Elec. Imports 50.08 63.60 12.80 25.21 % TWh

Solar & Wind^a 37.79 37.29 -0.49 -1.30 % TWh

Geothermal^a 6.19 6.08 -0.10 -1.63 % TWh

Renewable Waste 17.16 16.99 -0.17 -0.97 % TWh

Wood 76.52 78.74 2.22 2.90 % TWh

Biomass for Elec. 42.25 46.51 4.26 10.08 % TWh

- Biogas 22.81^b 22.19 -0.61 -2.68 % TWh

Global 1464.35 1481.15 16.8 1.15 % TWh

Technologies DHN 10.49^c 10.45 -0.04 -0.36 % TWh

Output CHP 35.06^d 35.80 0.74 2.11 % TWh

CO2 emissions (Fossil) 305.04^e 310.12 5.08 1.67 % Mt-CO2

CO2 emissions (Biomass) 45.99^f 47.86 1.87 4.06 % Mt-CO2

aData for renewable primary energy consumption are reported from [160] and from Sec. 3.1.8 in [144].

bFrom [127].

cFrom Table 9 in [6].

dFrom Fig. 17 in [158].

eFrom Table 1 (s1-s2) in [99]. Emissions of CO2 are evaluated considering only energy-related emissions and removing fugitive emissions from fuels (no aviation/navigation).

fFrom Table 1 (s2) in [99]. Emissions data are provided separating the operating emissions from fossil fuels and the emissions from biomass.

in Sec. 2.3.1. The main differences with respect to the actual values are due to some approximations: first of all, the electricity from Combined Heat and Power (CHP) plants is underestimated since the model is not able to deduce the effective alternation between co-generative and non-cogenerative mode of production (this latter contribution is not considered). Thus, in order to fill this production gap, Italy Energyscope overestimates the amount of imported electricity. Ignoring the use of derived heat for DH, the contribution of some biomasses classified as “Biomass for Elec.” in [156] and other minor fossil fuels such as coal by-products and half-processed oils contributes to other small differences between model outputs and the actual 2015 values in terms of energy flows.

In order to check the consistency of the environmental impact of the Italian sys-tem modeled, the actual energy related emissions from fuel combustion in 2015 are calculated in 310.12 Mt-CO₂ from [99], not including the contribution of fugitive emissions from fuels and the impact of internal navigation and aviation, not imple-mented into the modeling framework. This number is faithfully estimated by the Italy Energyscope model. The higher environmental impact of the modeled energy system is a consequence of the aforementioned approximations: principally, since imported electricity is related to an higher gwp_op than natural gas burned in CHP

plants (see Sec. A.5 in Appendix A), the emissions obtained by the model validation are higher than reality.

Finally, the proposed LP model formulation is able to offer an accurate rep-resentation of the Italian energy system in 2015 even if it does not fully consider the climatic and technological differences at a regional scale yet. The regional con-figuration of Italy, in fact, needs to be further studied and modeled since it can significantly impact on national energy consumption and emissions. Nonetheless, the model validation shows the consistency of the results provided by Italy Ener-gyscope, demonstrating its accuracy and reliability as modeling tool for strategic energy planning.

Decarbonization pathways

Energy models can help researchers and policy-makers to identify the best pathways towards low-carbon configurations of complex and heterogeneous national energy systems during the so-called energy transition. In this context, the Italy Energyscope modeling framework proposed in Ch. 2 has demonstrated to be suitable for Italian applications.

In this Chapter, starting from the Italian energy system described in Sec. 2.3.1, the future national energy transition is defined as well as the sectors in which stronger efforts in decarbonization are required. Then, the developed three-regions modeling zonal division of Italy Energyscope is presented and applied to the Italian case study with a 15-year planning horizon. Finally, a scenarios analysis is performed aiming at defining alternative pathways of decarbonization up to 2030 and beyond. These are classified in reference or policy scenarios, while the underlying assumptions considered for their definition are fully documented.

3.1 Case study: the Italian energy system in 2030

As described in Sec. 1.1.3, Italy has recently put in place new ambitious political measures in order to actively implement energy transition policies towards a low-carbon society. The key points of these policies, listed in “NES 2017” [155] and in the most recent “Proposta di Piano Nazionale Integrato per l’Energia e il Clima” [130], are: (i) strong decarbonization of the power sector; (ii) increase of electrification in the mobility and the heating sectors; (iii) improve of energy efficiency. In this context, the 2030 is considered a reference year in both European [56] and national directives [157] to check consistency and progresses of the proposed energy strategies towards the aforementioned goals.

In order to meet the ambitious emissions targets set by the EU and to guarantee a gradual shift towards electrification, Italy has planned several actions aiming at partially decarbonizing its energy system. The priority is not only to decarbonize, but also to modernise and innovate in a less carbon- and resource-intensive direc-tion. Firstly, a global phase-out of existing coal power plants has been scheduled by the year 2025, at the end of their technical lifetime [155, 88]. As illustrated in Figure 2.8, in 2015 thermal power plants fueled with coal had a 16% share of the total net electricity production representing an important flexible base-load capacity [160]. Thus, the planned phase-out of coal has to be reached with a parallel effort in finding alternative solutions for electricity generation. In this context, the next

decade will be likely characterised by a sharp increase of both already established (i.e. PV and onshore wind) and innovative (i.e. off-shore wind, Concentrated Solar Power (CSP), wave energy) RES for power generation [130]. This energy transition will be also favoured by the progressive decrease of the investment costs for all the renewable technologies as already experienced during the last few years. At present, in fact, wind and PV are in fact already close to being cost competitive with tradi-tional fossil-based generation options [12]. At the same time, the larger and larger availability of renewable electricity will contribute to promote the electrification of the mobility and the heating sectors through affordable and efficient technologies such as electric vehicles [26] and heat pumps [16]. The decarbonization strategy could then be extended to other fossil fuels such as petroleum products by 2050, with undoubted environmental and health benefits [45] and with an additional con-tribution to national objectives of increasing RES penetration and improving energy efficiency [88].

The energy transition of the Italian energy system up to 2030 will be however significantly affected by:

• regional availability and price of fossil resources, extremely difficult to predict and thus subjected by a huge uncertainty, as shown by Bezdek and Wendling [28];

• European constraints and prices related with CO2 emissions;

• R&D efforts in storage technologies and carbon capture, able to compensate the variability of RES and to reduce the environmental impact of traditional power plants;

• the strong modernisation of the electric grid in terms of security and adequacy, to handle the increasing intermittent and distributed electricity generation from RES;

• private investments on modern energy conversion technologies to make all the end-use sectors more resource efficient and electrified.

Thus, the future developments of the Italian energy system towards an efficient low-carbon configuration are multiple, hard to predict and strongly dependent on economic and technological efforts. In this context, the Italy Energyscope LP mod-eling framework described in Sec. 2.2 can be used as a supporting tool to asses and forecast which could be the most interesting pathways of decarbonization in terms of costs and environmental impact up to 2030. So, it will be applied to the Italian energy system with a 15-year planning horizon, starting from the configuration intro-duced in Sec. 2.3.1 and modeled in Sec. 2.3. However, identifying these alternative paths in an accurate and reliable way firstly requires further analysing the Italian energy system by taking into account the availability of resources, the efficiency of technologies, the productivity of RES and the energy demand at a (macro-)regional scale.