Results for Energy Production

Once the cost per kg has been determined, multiplication by the emitted quantities of the pollutants yields the cost per activity, for instance per kWh of electricity produced by a power plant. A complete accounting of the damage costs should involve a LCA, i.e., a complete inventory of emissions over the entire chain of processes involved in the activity. The total damage cost per kWh of electricity should include impacts upstream and downstream from the power plant, such as air pollution from the ships, trucks, or trains that transport the fuel to the power plant. That has been done for the fuel chain results of ExternE. A few results for France are shown in Figure 4.6.

For the fossil fuel chains, the lion's share of the external costs comes from air pollutants emitted by the power plant, the main impact categories being global warming and public health. Air pollutants from upstream and downstream activities make a relatively small contribution (roughly 10% of the GHGs). Apart from CO2, the damage cost is mostly due to health impacts, especially mortality.

The emission of toxic metals is highly uncertain and variable from one source of fuel to another; the numbers shown are not necessarily typical. However, they are in any case so small that their contribution to the total damage cost is negligible.

Recently updated and more complete results for power production in Europe have been calculated during the ExternE-Pol phase of the ExternE series (Rabl et al. 2004); they are shown in Figure 4.7 and Figure 4.8. The numbers are not completely comparable with those in Figure 4.6 because the methodology has been evolving. In particular, the numbers in the following are based on detailed LCA inventories provided by the ecoinvent database. Also the methodology for nuclear damage costs in Figure 4.7 is different from the one in Figure 4.6.

Results obtained for new and current technologies on the basis of ecoinvent are discussed in the remainder of this section. Figure 4.7 presents the results for current and advanced electricity systems, with the external costs per kWh in part a) and the contributions of the individual pollutants in part b). Likewise Figure 4.8 summarizes the results for the different heating systems.

cents/kWh

cents/kWh

FIGURE 4.6 Typical damage costs for electric power plants in France, for plants operating during the mid-1990s and for plants that respect the new EU regulations issued in 2000. Costs for nuclear are upper bound (0% "effective discount rate"); 90% of cancers from nuclear occur only after the first 100 yr. Retail price of electricity is about 7 cents/kWh; production cost of base load electricity about 3 cents/kWh.

FIGURE 4.6 Typical damage costs for electric power plants in France, for plants operating during the mid-1990s and for plants that respect the new EU regulations issued in 2000. Costs for nuclear are upper bound (0% "effective discount rate"); 90% of cancers from nuclear occur only after the first 100 yr. Retail price of electricity is about 7 cents/kWh; production cost of base load electricity about 3 cents/kWh.

Current fossil systems exhibit the highest external costs, in the range of 1.6-5.8 c€/kWh (Figure 4.7). Introduction of advanced technology (CC and PFBC) substantially reduces the external costs of fossil systems, but they still remain in the range 1-2 c€/kWh. This also applies to cogeneration, for which gas technology generates external costs one-third lower than diesel technology. Greenhouse gas (GHG) contribution to total costs prevails over other species for advanced fossil technologies, making about 80% of total external costs for CC and PFBC. Current averages of coal and oil plants show still high contributions from SO2, depending on the extension of installation of scrubbers in UCTE.

Nuclear external costs are below 0.19 c€/kWh of which 70% is radioactivity dependent. However, with discounting this contribution would strongly decrease, because most of the calculated damages from radiation are either related to very long-term emissions (e.g., radon from uranium mill tailings) or to very long-lived isotopes giving very small doses. On the other hand, the present estimation of external costs from ionizing radiation is based on a preliminary calculation using the disability-adjusted life years (DALY) concept, a rough attribution of cost/DALY, and an incomplete but important subset of isotope releases from the ecoinvent database. It is recommended to rework the estimation of damage factors from radioactive emissions in future projects of the ExternE series. The nuclear power plant itself contributes 5% or less to external costs from the nuclear chain.

Wind onshore with nearly 0.09 c€/kWh performs slightly better than wind offshore with 0.12 c€/kWh. Monocrystalline silicon photovoltaic (PV) panels of European fabrication, installed in Southern Europe cause nearly 0.28 c€/kWh, which would mean 0.41 c€/kWh for the average yield of 800 kWh/kWpeak yr in Central Europe. Assuming improvements in manufacturing technology of crystalline silicon, improved cell efficiency, and an expanded PV market, 0.21 c€/kWh has been estimated for future (2010) systems. External costs associated with imported panels may differ due to different manufacturing technology and electricity supply. Due to the relatively high material intensity of PV and wind, the contribution from heavy metals is about 15% and nearly 25%, respectively. Hydropower exhibits the lowest external costs of all systems, below 0.05 c€/kWh, but costs may increase on sites where higher direct emission of GHG from the surface of reservoir occur.

In general, gas boilers have lower external costs than boilers burning light oil: approximately 0.6 c€/kWhth vs. 0.94 c€/kWhth (Figure 4.8). The upstream chain of gas and light oil contributes

FIGURE 4.7 External costs of current and advanced electricity systems, associated with emissions from the operation of power plant and with the rest of energy chain. (a) The costs in €cent/kWh. (b) The contribution of the individual pollutants.

Cogeneration (all.exergy) Gas

UCTE El.

Nuclear El.

UCTE El.

Nuclear El.

□ Conversion unit

i

Iii Ii

H

-

1

II

i

Wood

Cogeneration (all.exergy)

Cogeneration (all.exergy)

FIGURE 4.8 External costs of heating systems, associated with emissions from the operation of boiler/cogeneration unit and with the rest of energy chain. (a) The costs in €cent/kWh. (b) The contribution of the individual pollutants.

roughly one-third to the total external costs. GHG contribute two-thirds of the total external costs for oil, over 80% for gas boilers. Burning heavy oil gives the highest damages with over 1.7 c€/kWhth, where S02 makes about 33% and GHG 38% of the damages. A range of about 0.7-0.8 c€/kWhth has been calculated for wood boilers, where the upstream chain contributes 20%-30% to total damages. Particles and nitrogen oxides emissions contribute most, i.e., nearly 60% and about 30%, respectively, to total damages. The modern fireplace gives more than 1.5 c€/kWhth, mostly due to the high particle release. GHG contribute 7% or less to total external costs for modern wood systems, because the CO2 from wood combustion is compensated by tree sequestration.

Cogeneration plants perform well when allocation is based on exergy: 0.36 c€/kWhth for diesel and an average of 0.27 c€/kWhth calculated for the gas units. The magnitude of external costs of heat pumps (HP) is controlled basically by two factors: the seasonal performance factor (SPF) and the energy supply source. For current systems and average UCTE electricity mix the external costs are nearly 0.7 c€/kWhth and 0.9 c€/kWhth for the air-water HP and brine-water HP, respectively. Due to the fact that about 26% of the UCTE electricity mix is from coal systems, damages from SO2 contribute nearly one quarter to the total external costs. For future HP technologies and electricity delivered by gas CC or nuclear, these costs go down to 0.26 c€/kWhth and 0.21 c€/kWhth, or nearly 0.08 c€/kWhth and 0.06 c€/kWhth, respectively, for the two heat pump systems and the two electricity supply cases (Figure 4.8).

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