Table 7.17. Danish energy demand 1992 in PJ per year (S0rensen et al., 1994a).

Table 7.17. Danish energy demand 1992 in PJ per year (S0rensen et al., 1994a).

The current demand is shown in Table 7.17 and the energy system in Figs. 7.22 and 7.23. These are based on 1992 data, because these were used as starting point in the ecologically sustainable scenario, including the attempt to distribute the end-uses on categories of energy quality. From 1992 to 1996, the Danish oil and gas production in the North Sea increased, although this is not expected to continue to 2030 (the scenario year for the future scenarios), because of the limited resources expected in the Danish part of the North Sea. In 1992, coal is still the major source of electric power production, and renewable energy use is increasing although still modest.

The delivered energy in Table 7.17 is the energy delivered to the end users. The net energy subtracts conversion losses in local boilers and furnaces, but does not correct for conversion losses in the transport sector. The estimated end-use energy is the true net energy needed to deliver the services of the actual system, had all been delivered by the most efficient devices available today (note that the subdivisions are different from those of the left-hand side of the table). The net energy for heating includes hot water used in the domestic and service sectors, whereas this has been listed as low-temperature process heat in the end-use column. The net energy for electrical appliances includes heating of water and low-temperature cooking, which in the end-use column is included under process heat below 100°C, and some stationary mechanical energy used in the service industry. The net process energy includes not only true process heat used in agriculture and industry, but also space heating, hot water, stationary mechanical energy and energy for electric appliances used in these sectors. In the end-use columns, an attempt has been made to categorise these correctly, and again to adjust to the efficiency of the best conversion equipment. For the transportation sector, the end-use energy is obtained by applying an average conversion efficiency of current vehicles.

Figures 7.22 and 7.23 gives a picture of the 1992 conversions between the primary and end-use energy in the Danish system, starting in Fig. 7.22 with a picture of the agricultural sector in energy units. This illustrates the large magnitude of agricultural energy manipulations and the small fraction of these presently contributing to energy supply, i.e. wood, straw, biogas and residues, not counting the energy provided by food. Each device is described by three numbers: energy input, loss and energy output. In this way, the assumed efficiency of each conversion can be seen.

The energy conversions illustrated in Figure 7.23 indicate a fairly efficient range of intermediate conversions, followed, however, by a relatively inefficient range of end-use conversions, particularly as regards the combustion engines used in the transportation sector. Efficiencies of electrical appliances have not been estimated here, but may be found together with efficiency analyses of other conversion equipment in Serensen (1991), and in a condensed form in Serensen (1992a). Non-energy uses of fuels (e.g. oil as feedstock for the plastics industry and tar for road construction) have been omitted from the overview.

In Table 7.18 the results of LCA calculations for the current Danish energy system are given. The two variations of the calculation are based on the product view (labelled "F" for full chain calculation) and the economy view

Figure 7.22. Overview of 1992 Danish biomass sector, with energy links but excluding indirect energy inputs for fertilisers, farm machinery, etc. Units are PJ y-1 (Soren-sen et al., 1994a; Sorensen, 1996c).
Figure 7.23. Overview of Danish energy system 1992. Units are PJ y 1 (Sorensen et al., 1994a; Sorensen, 1996c).

(labelled "D" for calculation based on impacts arising from domestic activities), as explained above. As there are impacts not evaluated, this is a partial analysis, and the sum of all calculated impacts cannot be taken as representing the totality of impacts.

In the year 1992 used as basis, Denmark imported some hydro-based electricity from Norway (cf. Fig. 7.23). This gives rise to an externality cost of 13.3 Meur y-1, which has been included in both calculations. The calculation also estimates the greenhouse warming impacts of materials used in the energy sector, assuming that they are all imported, and of international transport. These are included in the F-calculations, but not in the D-calculations, where they constitute 10800x106 kg CO2-equivalent or slightly more than the difference between the F- and D-calculations, owing to the net energy import in the year considered. For occupational impacts, the accidental deaths are small numbers that exhibit statistical fluctuations from year to year, whereas the larger numbers of injuries are more statistically significant and less fluctuating between years.

Impacts from traffic are taken as entirely domestic impacts except for emission-related impacts. For impacts such as visual, noise, and barrier effects of traffic infrastructure, this is evident. In case of greenhouse warming, the F-type calculation includes international traffic on Danish carriers, whereas the D-calculation considers only domestic transportation. For air pollution impacts other than greenhouse warming, only impacts from domestic traffic were included in both calculations, because the data on dispersal and dose-response available to us assumed emission over land. For international sea or air transportation, the emissions would reach populated areas only after some atmospheric travel. This could be calculated using existing models, but we did not attempt such calculations.

It is seen that greenhouse warming impacts and a range of other impacts from the transportation sector dominate the picture of impacts included. It is believed that this would also be the case if impacts such as biodiversity and other impacts listed in section 7.4.3 were considered. However, if the valuation of greenhouse warming impacts were altered in the downward direction, e.g. by changing the statistical value of life or making it dependent on economic activity in different regions of the world, then the relative important of other impacts would increase, and it is no longer certain that impacts not included in this evaluation would have a negligible effect.

The evaluation of LCA impacts uses the Table 7.6 example for coal-fired power plants. This means that the atmospheric dispersion calculated for emissions from this particular power plant is considered representative for all Danish power stations. For other fuel combustion, the impacts are scaled up or down from those of the power plant calculations, using data such as those of section 7.4.12 for scaling. For fuel combustion in the transportation sector, the low emission height is considered in estimating the health impacts of land transportation. Also the several non-emission-related impacts identified in the transportation sector are included for this sector only.

Environmental impacts and public health


monetised value

Range of uncertainty

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