A reduction in consumption of up to 30% has been registered after the transition
from joint to individual metering. The reduction in consumption occurs rapidly – usually one to two years after the transition to individual metering – and the reduction is maintained in the subsequent years. Consumers must be provided with detailed information well ahead of the transition to individual metering
if a rapid reduction in consumption is to be achieved. The introduction of metering is a prerequisite if district heating consumers - be they members of building associations or people in dense/low dwellings - are to be motivated to invest in energy-saving activities. This article is an updated version of the article
“The installation of meters leads to changes in consumer behaviour” from News from DBDH 3/1999.

Background
The expansion of the municipality of Albertslund, located to the west of Copenhagen, took off at the beginning of the sixties. Prior to 1963, the area contained only the villages of Herstedøster, Herstedvester and Vridsløselille, as well as a number of farms and nurseries. As the municipality grew, the first steps towards the building of Albertslund Fjernvarme (the local district heating plant), were taken in 1963. The introduction of a district heating system guaranteed a source of cheap heat for the consumers who were connected to the network. In addition, it offered the possibility of exploiting the surplus heat from the municipal waste incineration plant which became operational in 1969. The explosive expansion of the municipality meant that by 1974 the capacity of the heating plant had increased to 149 MW. The share of the district heating production which did not originate from the waste incineration plant was based on fuel oil.
Albertslund Fjernvarme was set up as a municipally owned company, unlike the majority of the district heating companies in Denmark, both then and now.
As fuel oil was so inexpensive at the end of the sixties and the beginning of the seventies, it did not make sense economy wise to install meters in the homes of consumers. The district heating charge applied at the time was very simple: consumption was calculated on the basis of the floor area (in square meters) of the individual building in relation to the total floor area supplied by Albertslund Fjernvarme.
In the beginning of the seventies, 92% of the Danish energy consumption was based on imported oil. Therefore it came as a shock to the country when Denmark, along with the rest of Western Europe, fell prey to the serious oil supply crisis that dominated the winter of 1973/74. One immediate
consequence of the supply crisis was a threefold increase of the price of oil over the course of just six months.
In both 1974 and 1977 the municipality of Albertslund issued reports which showed that potential savings in the consumption of district heating were not thought to warrant the additional costs associated with the introduction of a meter-based charging system, regardless of the dramatic increases of the price of imported oil. The reports concluded that the introduction of other energy-saving measures would be more profitable in economic terms than the installation of meters. The municipality therefore prepared an ”Energy Saving Plan” in which all aspects of buildings supplied with district heating were examined in detail. A list of possible energy-saving measures was prepared, out of which the following may be mentioned:

• Sealing of gaps.
• Additional insulation provided by secondary glazing.
• Reinsulation of outer walls and/or roof.
• Insulation of external cellar walls to approx. 1 meter below the ground.
• Outdoor temperature-dependent control with night/weekend reduction.
• Adjustment of heating systems.
• Regulation of room temperature by means of radiator thermostats.
• Regulation of room temperature by means of room thermostats that start and stop the heating system.
• Increased recirculation/periodic operation of ventilation systems.
• Replacement of hot-water tanks.

Legally, however, Albertslund Fjernvarme was unable to force individual district heating consumers to implement the suggested energy-saving measures. There was insufficient motivation to invest in the energy-saving measures, since the existing settlement charge was not based on individual consumption in individual homes.
The introduction of meters was therefore necessary if the energy-saving measures were to be put into place. The district heating consumption could be measured using the branch pipe that leads to the individual building, or using an area reading taken from the branch pipes that supply a group of buildings such as a housing estate. The delimitation of an area reading was defined as follows: ”The area delimited by a branch pipe with one decision-maker for the implementation of energy-saving measures”.
In areas with building associations and owner-occupied flats, the readings would be taken from the main branch pipes (joint settlement). For other consumers, the readings would be taken where the branch pipes were connected to the individual properties (individual settlement). In cases of joint settlement, it was up to the individual building association to distribute the costs amongst the individual homes.

Building associations usually chose to distribute consumption according to the floor area of the individual home in relation to the total floor area of the apartment block. This ”charge” was simple to administer, but it did not motivate individual consumers to reduce their heat consumption.

Following the installation of a total of 2,400 meters in 1981, Albertslund Fjernvarme changed its system on January 1, 1982, when a two-part charge was introduced:

• A fixed charge designed to ensure that the fixed costs of the heating plant were covered regardless of the district heating consumption. The charge was set as a fixed sum/m2 of connected heated area.
• A variable charge designed to cover the variable costs of the heating plant. The charge reflected the consumer’s registered consumption.

Experience
The following sections focuses on the heat consumption of a number of representative dwellings during the period 1991–2005, in order to establish whether the location of the meter (i.e. the use of joint or individual metering) affects the behaviour of consumers and thereby the heat consumption.
The following use of the term “individual metering” refers to the measurement of heat consumption in individual households, using either energy meters or evaporation meters located on radiators. The behaviour of consumers in individual households will thereby be directly reflected by the individual readings and, consequently, the amount paid by the consumer.
The term “joint metering” applies in all other cases.
The figures given here cover consumption resulting from heating and the production of hot domestic water. The figures for consumers have also been adjusted according to the numbers of degree days to reflect the yearly mean consumption, thereby enabling direct comparisons to be drawn.
The buildings are characterised by having either joint metering for the entire period, or by having changed from joint metering to individual metering over the course of the period. The study focuses on three types of buildings:

• Dense/low owner-occupied dwellings (terraced houses)
• Dense/low rented dwellings (terraced houses)
• Multi-storey buildings

Dense/low owner-occupied dwellings (Figure 1)
In this case, the buildings were Platanparken (160 houses) and Elmehusene (106 houses). They are identical in terms of their construction time, size and ownership.
This enables any potential differences between the settlement method and consumption to be seen clearly. The only difference between the two developments is that Platanparken had individual metering
for the entire period. Elmehusene had joint metering until July 1,1995, when individual metering was introduced. In both cases, heat consumption is based on the readings taken from the main meter.
The results show clearly that the consumption figures for Elmehusene (joint metering)
were significantly higher (up to 44%) than those associated with Platanparken during the period before 1995. Following the introduction of individual metering at Elmehusene, the consumption was significantly
reduced and is now on par with the consumption at Platanparken. Since 1991, the consumption at Platanparken has been reduced by 17%. At Elmehusene, however, it was reduced by 31%. The introduction of individual metering has therefore resulted in a significant reduction in consumption.

Dense/low rented dwellings (Figure 2)
The buildings in this case were Hyldespjældet (390 houses) and Morbærhaven (1,063 houses). Hyldespjældet had joint metering until the end of 1997, when the houses switched to individual metering. On the other hand, the buildings at Morbærhaven had joint metering for the entire period.
The results clearly show that the consumption
at Hyldespjældet fell by 31% in comparison with the consumption in 1997, following the introduction of individual metering in 1998. Over the entire period from 1991, consumption has been reduced by more than 42%. The consumption at Morbærhaven has been reduced by around 28% since the introduction of meters in 2000. The fact that it was possible to reduce consumption at Hyldespjældet by more than 42% and at Morbærhaven by more than 36% since 1991 must be seen in light of the fact that the consumption in 1991 was relatively high. This created a good basis for a reduction.

Multi-storey dwellings (Figure 3)
The buildings in this case were Topperne (383 houses), Albertslund Nord (224 houses) and Banehegnet (184 houses). Topperne had joint metering until the end of 1992 when individual metering was introduced. Both Albertslund Nord and Banehegnet had joint metering until the end of 1995 when individual metering was introduced.
Once again, the results speak for themselves.
Consumption is reduced following the transition to individual metering, with the reduction appearing at the latest two post-transition years. The reduction was highest in the case of Topperne, with a registered drop in consumption of 21% from 1992 to 1994. A drop of 15–17% from 1995 to 1997 was registered in the case of the other two developments. All three developments noted a further reduction up till 2005.

Summary
A reduction in consumption of up to 30% can be registered following the transition from joint to individual metering. The reduction becomes apparent relatively quickly, usually one or two years after the transition to individual metering, and it is maintained in the subsequent years. It is also possible to conclude that houses which have identical consumption figures in connection with joint metering show sizeable variations of up to 20% following the transition to individual metering. It is therefore impossible to calculate the exact expected reduction in consumption following the transition to individual metering. However, a drop of at least 15–17% is a realistic result.

The speed with which the reduction in consumption is registered following the transition to individual metering depends on a number of factors, including the quality of the information given to consumers before the transition to individual metering.
When a general requirement to reduce energy consumption exists, and if district heating consumers - be they housing associations or members of other consumer categories - are to be motivated to invest in energy-saving activities, it is absolutely vital that metering is introduced. Only if the consumers themselves feel that they benefit from the advantages achieved by investing in energy-saving measures, will they choose to make such investments.

For further information please contact:
Albertslund Varmeværk
Att.: Mr. Michael Poulsen
Postadresse: Vognporten 9,
DK - 2620 Albertslund
Phone: +45 4364 8692
Fax: +45 4364 3888
E-mail: michael.poulsen@albertslund.dk
VEKS
Att. Mr. Lars Gullev
Roskildevej 175
DK - 2620 Albertslund
Denmark
Phone: +45 4366 0366
Fax: +45 4366 0369
E-mail: lg@veks.dk