Comparison with previous studies

1.6.1 Scope and approach

In comparison to the previous analysis of potentials and costs of domestic electricity production and electricity imports (Hirschberg, Bauer et al. 2005), the scope of the present analysis is substantially more comprehensive:

• Several additional technologies are considered: large hydropower, natural gas combined cycle plants, CHP units and fuel cells, coal power, fossil power plants with CO2 capture and novel technologies (Hydrothermal methanation of wet biomass, novel geothermal technologies, nuclear fusion, thermoelectrics).

• The analysis includes an evaluation of environmental burdens based on life-cycle assessment.

• Swiss-specific ranges for both electricity generation costs and environmental impacts are – as far as possible – provided in a consistent way for all technologies.

• Sensitivity of electricity generation costs is analyzed in a consistent way for most of the technologies.

• The whole analysis has been carried out in a more systematic, transparent and comprehensive way concerning differentiation according to technology specification, used references and input data as well as underlying assumptions.

• This analysis was extensively reviewed by experts from the federal offices, industry and academic institutions.

• The results of the analysis of electricity generation potentials and costs as well as environmental impacts are provided in the context of other national and international studies.

1.6.2 Estimates for electricity generation costs and potentials

Electricity generation potentials and generation costs from this analysis are compared to previous estimates according to (Hirschberg, Bauer et al. 2005, Hirschberg, Bauer et al. 2010, Densing, Hirschberg et al. 2014, Densing, Panos et al. 2016)⁴⁰: maximum renewable generation potentials⁴¹ (Figure 1.8) and LCOE in 2050 (Figure 1.9) are used for this purpose.

Reference technologies and their applications are not always specified in detail in the various references, which might distort the comparison. Concerning generation potentials, only hydropower, electricity from biomass, deep geothermal, wind power and photovoltaics can be compared; the recent studies do not provide consistent data for other energy carriers and technologies. Concerning electricity generation costs in 2050, only LCOE from PV, wind power, natural gas CC plants and nuclear power can be compared. The evaluated studies do not provide data for other technologies and energy carriers.

The estimate for additional hydropower generation in the present analysis (“PSI 2017”) includes both small and large hydropower; it’s not clear whether this is also the case for the other studies, or whether only large hydropower is addressed. The comparatively low

40 Densing, Hirschberg et al. (2014) compiled an extensive comparison of recent Swiss energy scenarios according to major studies, with explicit comparison of renewable generation potentials and generation costs.

41 Consistent numbers from other studies are only available for hydropower, electricity from biomass, photovoltaics, wind power and deep geothermal power and refer to the “the economic and socially acceptable potential”, which is here assumed to correspond roughly to “constrained technical potentials” or “exploitable potentials”, as specified in this analysis.

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numbers from (Barmettler, Beglinger et al. 2013, Teske and Heiligtag 2013) are due to environmental issues disfavoring a further expansion of hydropower. Variations of biomass-to-electricity potentials are due to different primary data sources and different assumptions concerning conversion technologies as well as competing biomass utilization (for heating and transportation purposes). The previous analysis of PSI (Hirschberg, Bauer et al. 2005) did not include large hydropower and biomass-to-electricity potentials. Wind power potentials are relatively uniform across the studies, most of them being based on the same primary source. In case of deep geothermal power, most of the studies (including this one) refer to the federal long-term target; this can only be realized, if current geological, technical, legal, social and economic barriers can be overcome (Hirschberg, Wiemer et al.

2015). PV potentials show the highest variations; however, it’s unclear, whether all studies refer to roof-top PV installations only⁴², or also include facade and open-ground installations.

Figure 1.8: Maximum renewable generation potentials in Switzerland according to various recent evaluations. Consistent data for other technologies and energy carriers are not available. “Hydro” includes only additional generation from new and refurbished hydropower plants; for all other technologies, current generation is included⁴³. PV: photovoltaics; ETH/ESC: (Andersson, Boulouchos et al. 2011); VSE: (VSE 2012);

BFE: (Prognos 2012a); Greenpeace: (Teske and Heiligtag 2013); Cleantech: (Barmettler, Beglinger et al. 2013);

PSI-elc: (Kannan and Turton 2012b, Kannan and Turton 2012a); PSI-sys: (Weidmann 2013); SCS: (SCS 2013);

PSI 2005: only potentials for wind power and photovoltaics were quantified for 2050 (Hirschberg, Bauer et al.

2005); PSI 2010: (Hirschberg, Bauer et al. 2010); “PSI 2017” includes roof-top PV potentials only in this graph.

A more detailed comparison with (Hirschberg, Bauer et al. 2005) shows that the potential of small hydropower estimated in the present analysis is slightly lower. Wind power potentials remain basically equal, since major new estimates are not yet available. PV potentials of this analysis are higher than they have been before, due to new primary data sources and a

42 For the present analysis (“PSI 2017”), this graph only includes generation potential from roof-top PV installations; available numbers for additional potential for facade PV installations are provided in chapter 9.3.

43 Included due to limited data availability in original references.

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more detailed analysis of future technology development. The new estimates for import of concentrated solarthermal power and power from the ocean are slightly higher, but of the same order of magnitude.

Figure 1.9: Electricity generation costs (LCOE) of different technologies in Switzerland in 2050 according to various sources. Consistent data for other technologies and energy carriers are not available. PV:

photovoltaics; ETH/ESC: (Andersson, Boulouchos et al. 2011); VSE: (VSE 2012); BFE: (Prognos 2012a);

Greenpeace: (Teske and Heiligtag 2013); Cleantech: (Barmettler, Beglinger et al. 2013); PSI-elc: (Kannan and Turton 2012b, Kannan and Turton 2012a); PSI-sys: (Weidmann 2013); SCS: (SCS 2013); PSI 2005: (Hirschberg, Bauer et al. 2005). n.a.: not analyzed. Cost ranges can indicate variation in technology specification, expected technology development, site-specific aspects or interest rates and are not always further specified in the references used. Not all references provide ranges.

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Comparing estimated LCOE in 2050 from the present analysis with figures from the other recent studies shows that the range of generation costs from PV is broadest in the present analysis, since a wide range of unit capacities has been considered and large plants are substantially cheaper than small plants; in addition, this analysis takes into account variation due to the range of possible yields in Switzerland. Almost all LCOE from PV from other studies are within the range provided by this analysis. LCOE of wind power of this analysis are within the range of all other studies. LCOE of natural gas CC plants are relatively high compared to the other studies, which mainly seems to be due to the comparatively strong increase in gas prices assumed in this analysis based on authoritative sources.

A more detailed comparison with (Hirschberg, Bauer et al. 2005) shows that LCOE estimates for 2050 for small hydropower have slightly increased; new estimates for generation costs from PV are substantially lower, reflecting the strong decrease in module costs in recent years. Previous estimates for LCOE of wind power are within the range provided by this analysis. LCOE estimates for future nuclear power have increased compared to previous results. New estimates for CSP are lower than previous ones, while estimates for LCOE of deep geothermal power have increased. LCOE of electricity-to-biomass, large hydropower, wave and tidal power, electricity from natural gas CHP and fuel cells as well as coal power and natural gas and coal power plants with CO2 capture have not been quantified in (Hirschberg, Bauer et al. 2005). In general, the comparison of LCOE shows the importance of a transparent procedure in quantification of LCOE with explicit specification of technology characteristics and input data.