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Denmark´s Second National Communication on Climate Change

6.1 Carbon Dioxide, CO₂

6.1.1 The Energy Sector

Assessment of measures

As part of the energy action plan, Energy 21, future Danish energy consumption and CO₂- emissions related to this consumption have been assessed for the period 1995 - 2030.

The development in energy consumption and CO₂ emissions described in this section is based on Energy 21 although the projections for 1995 have been replaced by actual figures.

The short term goal of Energy 21 is to reach the Danish Government's target of reducing CO₂ emissions from the energy-consuming sectors by 20% in 2005 as compared to the 1988 level. A number of initiatives aiming at reaching this goal have therefore been implemented in the Danish energy policy, as described in Chapter 5 and Annex F.

The assessment of the development for the period 2005 - 2030 is based on more general considerations, among others

• Conservation of heat and electricity
• Use of energy efficient appliances and processes
• Use of renewable energy.

It is assumed that international common efforts during this period will contribute substantially to reducing Danish CO₂ emissions.

For the transport sector, the Government has prepared a transport action plan, the objectives of which are to stabilise the sector's CO₂ emissions at the 1988 level by 2005, and to reduce emissions by 25% before 2030. Use of energy efficient cars is one of the major contributors to the emission reduction within the transport sector, and development of such cars, internationally, is therefore of major importance.

Calculation Method

The calculation method used for the projections is described in the report Energy 21 - Preconditions and Results, (Danish Energy Agency, 1997). In the following, a brief description of the calculation method is given.

Computer models

The projections are based on calculations carried out by a number of separate models, as illustrated in Fig. 6.1. The calculations are carried out specifically for the three years 2005, 2020 and 2030, with actual energy consumption in 1994 being used as the basis for the projections. For all other years within the period 1994 - 2030 the calculations are carried out by interpolation. 

Fig. 6.1. Overview of models used for the calculation of primary energy consumption and CO₂ emissions.

Consumption model

Projections of the final energy consumption for all sectors except the transport sector are calculated in two steps using the consumption model:

First, a future energy consumption based solely on external factors is calculated. The actual 1994-consumption is used as starting point, and the development is based on assumed developments of external factors such as GDP, population, etc. Thus in this projection, no saving measures or fuel conversions are included.

Second, the changes in energy consumption due to improved efficiencies, altered consumer behaviour and conversions to other fuels and/or production methods are calculated. The calculations result in a specification of the total final energy demand, subdivided as electricity, district heating and different types of fuel.

Transport model

Projections of the final energy consumption within the transport sector are calculated in a separate transport model. The calculation principle is similar to the one used for the other sectors, i.e. the development in the need for transportation and the related energy consumption is first calculated, and the effect of improved efficiencies etc. is then added. The calculations result in a specification of the total final energy demand, subdivided as electricity and different types of fuel.

Supply model

The calculated demands for electricity and district heat are used as input to the supply model, which calculates the amounts of different types of fuels necessary for the production of heat and electricity. The calculation is based on detailed information for a large number of existing and planned power, heat and CHP plants.

Totals

The total CO₂ emission from fuel combustion in Denmark is then calculated from the total consumption of different types of fuels projected by the consumption model, the transport model and the supply model.

Key Variables and Assumptions in the Projections Analysis

Detailed assumptions used for the projections are described in Energy 21 - Preconditions and Results, (Danish Energy Agency, 1997). Some key assumptions are summarized in Table 6.1.

Table 6.1. Summary of key variables and assumptions employed in the projections analysis. The figures for 1994 are actual values. All other figures are forecasts.

The economic fuel prices used for the Energy 21 calculations are listed in Annex G. A description of the Danish energy tax system is given in Annex H.

Future Development

The energy initiatives will lead to:

• Increasing efficiencies of electric appliances and other energy equipment
• Reductions in energy consumption due to improved consumer habits
• Conversions to other fuels and/or energy supply systems at consumer level
• Increased use of combined heat and power production
• Increased use of natural gas and renewables for heat and power production.

A description of all Danish energy-related Acts and measures is given in Annex F. How these acts and measures contribute to the above described development is described below. The figures in square brackets refer to the numbers in the annex.

Increased efficiencies

Increased efficiency of electric appliances and other energy equipment will, depending on the specific appliance, lead to reductions in energy consumption of 15 - 78% by the year 2030 as compared to the average 1995-consumption.

Box 6.1. Improvements due to increased efficiency. Figures in [ ] refer to Annex F.

Improvements after 2005 are assumed to result from continuation of the above mentioned measures, intensified measures where necessary plus increased influence from international measures.

The increases in efficiency have been assessed separately for the trade and industry sector, the residential sector and the institutional sector. The detailed assessment is presented in Energy 21 - Preconditions and Results (Danish Energy Agency, 1997). As an example, Fig. 6.2 shows the development in specific energy consumption for equipment used in trade and industry.

Fig.6.2. Planned development in specific energy consumption in trade and industry. Improved consumer habits

Apart from general response of energy taxation, reductions in energy consumption due to improved consumer habits are assumed to be rather small.

Box 6.2. Improved consumer habits. Figures in [ ] refer to Annex F.

Fuel conversions

Consumer-level conversion to other fuels and/or energy supply systems comprises conversion from the use of oil, coal and electricity (for space heating) to the use of natural gas, district heating, heat pumps (based on electricity and natural gas), solar heat, straw, wood and other kinds of biomass. After 2005 conversion from natural gas to district heating is also assumed to take place due to expansion of the district heating networks.

Box 6.3. Fuel conversions. Figures in [ ] refer to Annex F.

Improvements after 2005 are assumed to result from continuation of the above mentioned measures plus intensified measures where necessary.

To illustrate the effect of fuel conversions, the assumed conversions for industry are shown in Fig. 6.3. The use of heat from local CHP plants instead of oil and coal constitutes a major part of the conversions. The detailed assessment of fuel conversions is presented in Energy 21 - Preconditions and Results (Danish Energy Agency, 1997), for the industrial, commercial, institutional and residential sectors, respectively.

Fig. 6.3. Conversion to other fuels and energy sources for process energy and space heating in industry.

The increased use of combined heat and power production contributes substantially to the improvement of overall energy efficiency.

Combined heat and power production

Box 6.4. Combined heat and power production. Figures in [ ] refer to Annex F.

The development in electricity production is shown apportioned by source in Fig. 6.4.

Use of natural gas and renewables

Fig. 6.4. Electricity production by source.

The increased use of natural gas and renewables for heat and power production will result in a gradual phasing out of coal and oil by 2030. Today, coal is mainly used at the large power plants, while only a minor amount of oil is used in electricity production. In Energy 21 it is assumed that all new plants to be built until 2030 will use natural gas and/or renewables. The use of coal and oil will then be reduced as the existing plants are being scrapped. Additionally, a large increase in use of wind turbines plus a certain use of photovoltaic energy, geothermal heat and wave energy is assumed in the last part of the period. After 2005, energy crops will contribute to the supply with renewable fuels.

Development in the consumption of different fuel types for electricity and district heating is shown in Fig. 6.5.

Box 6.5. Use of natural gas and renewable energy. Figures in [ ] refer to Annex F.

Development in the consumption of different fuel types for electricity and district heating is shown in Fig. 6.5.

Fig. 6.5. Fuel consumption for electricity and district heating.

Transport sector

Within the transport sector, a large number of measures are assumed to be implemented in order to obtain the CO₂ emission reduction goal for this sector.

Box 6.6. The transport sector.

Main Results of the Projections Analysis

Primary energy consumption

On the basis of key variables and assumed future developments, projections have been made of total primary energy consumption for the period 1996 to 2030. This is shown apportioned by fuel type in Fig. 6.6.

Renewable energy

The use of renewable energy is projected to grow rapidly during the period. The expected use of renewable energy is shown apportioned by source in Fig. 6.7.

Fig. 6.6. Expected primary energy consumption apportioned by fuel type.

Fig. 6.7. Use of renewable energy shown apportioned by source.

CO₂ emissions

The expected CO₂ emission related to the energy consumption is shown in Fig. 6.8 which also shows the expected CO₂ emission for a "Business-as-Usual" scenario, updated from the Energy 2000 Plan drawn up in 1990. This scenario illustrates how CO₂ emissions would have developed from 1990 if no steps had been taken in order to reduce the emissions. Emissions from international transport are not included in Fig. 6.8.

The values for the period 1990 to 1995 are historical data corrected for variations in space heating demand and electricity exchange due to climatic variations. For comparison, uncorrected values for this period are shown as well.

The long-term development in the period to 2030 is expected to result in gradually increasing electricity export from Denmark. This export is not due to climatic variations, but arises from the technical lay-out of the power production system, with increasing shares of cogeneration and wind energy. Since the this export is not caused by climatic conditions, the projected CO₂ emissions are not corrected for this export.

Fig. 6.8. Planned development in CO₂ emissions from fuel combustion.

The national target of reducing CO₂ emissions from fuel combustion by 20% from 1988 to 2005 will be fulfilled by implementing the Energy 21 Action Plan, as the emissions covered by the target are projected to decrease slightly more. The targeted emissions include emissions from international air transport, while flaring is excluded. The target for 2005 as well as the base level of 1988 are defined in terms of emissions corrected for both electricity exchange and outdoor temperature variation.

CO₂ content of fuel mix

The average CO₂ content of the fuels consumed will decline markedly during the period. In 1995, the CO₂ content of the fuel mix was approx. 72 kg/GJ, which is close to the CO₂ content in fuel oil. In 2030, the CO₂ content will be approx. 35 kg per GJ, due to a large contribution from renewable energy. The expected development in CO₂ content of the fuel mix is shown in Fig. 6.9.

Fig. 6.9. Development in CO₂ content of the fuel mix.

6.1.2 Land use change and forestry

CO₂ uptake due to afforestation and in existing forests

When establishing new forests through afforestation, the CO₂ uptake per ha is not linear over time, but follows a non-linear pattern over a 70 - 150 year period with low starting and ending values, but with high net uptake in the middle period around 30 years after planting. While the average uptake over a 150 year period is around 0.004 Gg CO₂ per ha, much higher values are reached in the peak period. As a rough approximation projections have been made using the average value of 0.0041 Gg CO₂ per ha per year until 2009, and a higher average, influenced by peak uptake, of 0.016 Gg per ha per year from 2010 to 2030.

6.1.3 Total Carbon Dioxide Emissions

The expected development in CO₂ emissions is shown apportioned by purposes in Table 6.2. A more detailed breakdown of the emissions from the fuel combustion is given in Annex B, which contains sectoral energy balances and resulting CO₂ emissions for the years 1990, 2000, 2005, 2010, 2020 and 2030.

Table 6.2. Projected CO₂ emissions from Denmark for the period 2000 - 30 compared to the emissions in 1990.

As a contribution to the overall stabilisation of CO₂ emissions by the year 2000 for the EU countries, Denmark has committed itself to achieve a 5% reduction in 2000 compared with 1990.

As can be seen from the table, the Danish CO₂ emission will decline from 59,958 Gg in 1990 (corrected for electricity exchange and outside temperature variation) to 54,309 Gg in 2000. This corresponds to a decrease of 9.4%, and the 5% target is therefore expected to be fulfilled. The CO₂ benefit of increasing the forest area has not been taken into account in these figures.

6.2 Methane, CH₄

6.2.1 Agriculture.

Due to the EU ceiling on the national milk production and the increased milk production pr. milking cow both the number of milking cows and the cattle stock are expected to decrease in 2010. As the same emission factors are used for 1990 - as in Chapter 4 - and 2010, methane emissions are reduced accordingly compared to the 1990 - level.

On the other hand, however, the production of pigs is expected to grow substantially from 1990 to 2010, and the reduction in methane emissions gained from cows/cattle is largely offset by the increase in the methane emissions from pigs.

Table 6.3. Projected methane emissions from Denmark over the period 2000 -10 compared to the emissions in 1990.

6.2.2 Waste.

The effect of the Action Plan for Recycling and Waste is expected to be a substantial reduction in landfilling of waste from the domestic sector, gardens and the commercial sector before 2000. After 2000, the landfilling from these sectors is expected to cease completely and the most important sources would then be bulky waste, industrial waste, waste from building and construction, sewage treatment and ash & slag.

Using a half-life of 10 years, the total integrated CH₄-emissions from open landfills are estimated to be as shown in Table 6.3.

Total Danish methane emissions in 2000, 2005 and 2010 are therefore predicted to be 408, 377 and 362, respectively.

6.3 Nitrous oxides, N₂O

Danish initiatives to substantially reduce the use of in particular commercial fertiliser before 2000 are expected to significantly reduce N₂O emissions from the agricultural sector from an estimated 30 Gg in 1995 to around 26 Gg per year from 2000 onwards.

Table 6.4. Projected N₂O emissions from Danmark over the period 2000 - 10 compared to the emissions in 1990.

Total Danish N₂O emissions 2000 - 10 are predicted to be 28 Gg.

6.4 Other emissions

The projections also includes NO_x, CO, NMVOC and SO₂ - emissions.

In Table 6.5 the national totals of these projections are shown.

The projections are based on the Danish action plans and include the fullfilment of the Danish commitments under the Convention on Long-Range Transboundary Air Pollution.

Table 6.5. Projections of Danish NO_x, CO, NMVOC and SO₂ - emissions 2000 - 30 in Gg compared to the emissions in 1990.

Note: Numbers in colums may diverge from table 4.5, 4.6, 4.7 and 4.8 due to the use of different calculation methods.

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