*3.2. Pathway Results*

The main results from the pathway analysis, i.e., energy use per energy carriers and carbon emission reductions, for the construction of buildings and transport infrastructure up until 2045, are depicted in Figures 7 and 8. The results show that it is possible to reduce CO2 emissions associated with construction of buildings and transport infrastructure by at least 50% to 2030 (51–62%), and reach close to zero emissions by 2045 (90–94%) with the electrification and material efficiency pathways demonstrating the highest reductions. The energy use is also reduced in all pathways albeit with more variance between the pathways (6–19% to 2030 and 16–37% to 2045). In addition, regarding energy use, it is the electrification and material efficiency pathway which demonstrates the highest reductions.

The analysis demonstrates that currently, construction of buildings and transport infrastructure use approximately 32 TWh energy, accounting for around 8% of total Swedish energy use [156]. All the pathways demonstrate a reduction in total energy use over time, with the reduction varying from 6–19% to 2030 and 16–37% to 2045.

When comparing the total energy use, the electrification pathways demonstrate a total energy use of around 6–8% lower than the biofuel pathways in by 2045. This is mainly a result of the lowered energy requirements from electric propulsion compared to combustion engines for construction equipment and heavy-duty trucks combined with the energy penalty for post-combustion carbon capture for cement production.

**Figure 7.** Energy use for each energy carrier over time for the buildings and transport infrastructure pathways.

A focus on material efficiency has the potential to reduce total energy use by 8–10% to 2030 and 18–20% by 2045 for both the biofuel and electrification pathways (noting that the reduction potential would be even higher compared to a reference scenario).

Regarding biofuels, they are at current mainly used in the transport sector, and in asphalt, timber and cement production. Over time, the use is set to expand with the overall share of biofuels increasing from 15% of total energy use at current to around 30% in the electrification pathways and to 40% in the biofuel pathways by 2045. This would mean an increase from 5 TWh to 9 TWh, which can be compared with the current total bioenergy use of 89 TWh in 2017 [156].

Electricity use remain almost constant in the biofuel pathways, while increasing from 7 TWh up to 13–16 TWh in 2045, reaching a share of around 40% in the biofuel pathways and 65% in the electrification pathways.

As can be seen in Figure 8, all pathways reach close to zero emissions in 2045, with total emissions reduction of 90–94%, with the highest emission reduction potential in the electrification pathways. Up until 2030, we see potential emissions reductions of 51–56% for Pathways 1 and 2, indicating that the emissions reduction goal of 50% set by the Construction and Civil Engineering sector in in its own roadmap [49] could be met if the measures suggested in this roadmap would be implemented. Before 2030, most emissions reductions stem from increased use of alternative binders combined with reduced binder intensity in concrete (25%), as well as optimization and energy efficiency measures on the construction sites combined with biofuel substitution in construction equipment and material transports (36–40%). The biofuel substitution partly ensues as a result of the Swedish reduction duty regulation, which specifies increasing emissions reductions in line with a growing share of renewable content in diesel fuel [157]. The emission reduction up until 2030 is also supported by the use of

reinforcement steel produced only from recycled steel combined with measures, such as improved electricity emissions factors together with material and fuel substitutions regarding insulation materials.

**Figure 8.** Results on CO2 emissions for the buildings and transport infrastructure pathways from 2020 to 2045.

A focus on material efficiency provides for additional reductions, particularly in the medium term. An additional 12% brings the total emissions reductions down to around 56–62% by 2030, implying a difference of 0.5–0.6 Mt CO2 emissions per year.

After 2030, deeper emissions reductions come about as a result of continued biofuel substitution combined with hybridization and electrification for construction equipment and trucks (contributing to a large share of the emissions reductions in 2030–2035). Fuel substitution also plays a role in primary and secondary steelmaking in 2030–2035.

In the biofuel+CCS pathways, this fuel substitution is combined with CCS in primary steelmaking, as well as in cement kilns (contributing to around 40% of the emissions reductions in 2040–2045, respectively).

In the electrification pathways, plasma heating is instead used to create the necessary temperatures in secondary steelmaking, cement kilns, in cracking, and polymerization for plastic production, as well as mineral wool production (contributing to around 45% of the emissions reductions in 2040–2045 combined). Electrification in the primary steelmaking in the form of hydrogen reduction also contributes considerably in the electrification pathway (40% in 2045).

In view of the remaining carbon budget, up to 2045 the material efficiency pathways could reduce the total cumulative amount of CO2 emitted from construction of buildings and transport infrastructure over the years 2020 to 2045 by 10% compared to its corresponding biofuel/electrification pathways, equivalent to 10–11 MtCO2.
