7.5.1 Electricity savings

Electricity savings are of particular interest, since they feedback into the mitigation potential calculation for the energy sector and because of the potential for double counting of the emissions reductions. Section 7.3.2 indicates that in the EU and USA electric motor driven systems account for about 65% of industrial energy use, and that efficient systems could reduce this use by 30%. About one-third of the savings potential was assumed to be realized in the baseline, resulting in a net mitigation potential of 13% of industrial electricity use. This mitigation potential was included in the estimates of mitigation potential for energy-intensive industries presented in Table 7.8. However, it is also necessary to consider the potential for electricity savings from non-energy-intensive industries, which are large consumers of electricity.

The estimation procedure used to develop these numbers was as follows: Because data could not be found on other countries/regions, US data (EIA, 2002) on electricity use as a fraction of total energy use by industry and on the fraction of electricity use consumed by motor driven systems was taken as representative of global patterns. Based on De Keulenaer et al. (2004) and Xenergy (1998), a 30% mitigation potential was assumed. Emission factors to convert electricity savings into CO₂ reductions were derived from IEA data (IEA, 2004). The emission reduction potential from non-energy-intensive industries were calculated by subtracting the savings from energy-intensive industries from total industrial emissions reduction potential. Using the B2 baseline, 49% of total electricity savings are found in industries other than those identified in Table 7.8.

Table 7.8: Mitigation potential and cost in 2030

Table 7.8 continued

Notes and sources:

^a Price et al., 2006.

^b Global total may not equal sum of regions due to independent rounding.

^c Kim and Worrell, 2002a.

^d Expert judgement.

^e Emission intensity based on IAI Life-Cycle Analysis (IAI, 2003), excluding alumina production and aluminium shaping and rolling. Emissions include anode manufacture, anode oxidation and power and fuel used in the primary smelter. PFC emission included under non-CO₂ gases.

^f Assumes upgrade to current state-of-the art smelter electricity use and 50% penetration of zero emission inert electrode technology by 2030.

^g Humphreys and Mahasenan, 2002.

^h Hendriks et al., 1999.

ⁱ Worrell et al., 1995.

^j Ren et al., 2005.

^k Basis for estimate: 10 GJ/t NH₃ difference between the average plant and the best available technology (Figure 7.2) and operation on natural gas (Section 7.4.3.2).

^l Rafiqul et al., 2005.

^m Worrell and Galitsky, 2005.

ⁿ Farahani et al., 2004.

^o The process emissions from ammonia manufacturing (based on natural gas) are about 1.35 tCO₂/t NH₃ (De Beer, 1998). However, as noted in Section 7.4.3.2, the fertilizer industry uses nearly half of the CO₂ it generates for the production of urea and nitrophosphates. The remaining CO₂ is suitable for storage. IPCC (2005a) indicates that it should be possible to store essentially all of this remaining CO₂ at a cost of <20 US$/t.

^p IPCC, 2005a.

^q US refineries use about 4% of their energy input to manufacture hydrogen (Worrell and Galitsky, 2005). Refinery hydrogen production is expected to increase as crude slates become heavier and the demand for clean products increases. We assume that in 2030, 5% of refinery energy use worldwide will be used for hydrogen production, and that the byproduct CO2 will be suitable for carbon storage.

^r Total potential and application potential derived from IEA, 2006a. Subdivision into regions based in production volumes and carbon intensities. IEA, 2006a does not provide a regional breakdown.

^s Extrapolated from US EPA, 2006b. This publication does not use the SRES scenarios as baselines.

^t See Section 7.5.1 for details of the estimation procedure.

^u Due to gaps in quantitative information (see the text) the column sums in this table do not represent total industry emissions or mitigation potential. Global total may not equal sum of regions due to independent rounding.

^v The mitigation potential of the main industries include electricity savings. To prevent double counting with the energy supply sector, these are shown separately in Chapter 11.

^w Mitigation potential for other industries includes only reductions for reduced electricity use for motors. Limited data in the literature did not allow estimation of the potential for other mitigation options in these industries.