Abstract

This master thesis aims to develop an assessment tool for the decision-making regarding the future establishment of low-temperature district heating (LTDH). The tool is created as an indicator system on behalf of Södertörns Fjärrvärme AB (SFAB). SFAB is currently responsible for the distribution of high-temperature district heating (HTDH) to customers in the municipalities of Huddinge, Botkyrka, and Salem. The indicator system is designed to, in a first assessment step, examine the initial conditions that a delimited area should have for conversion to lower system temperatures to be possible. Each indicator is quantified and graded to a complete scale. When using the system, a weighted final judgment is generated which tells whether an area is suitable for LTDH or not. Furthermore, the purpose of this thesis is to also evaluate the assessment tool by applying it to various areas within SFAB. This enables analysis and discussion regarding the tool’s function in a real context.

The development of the indicator system is the main result of the study. It consists of four indicators that take the following aspects into account: qualitative conditions (KA), conditions on the customer side (AA), the economic benefit (CRG), and the system condition (STA). The results from the implementation show that one out of five case areas have a good potential to be suitable for conversion to LTDH, while the remaining fall below the limit for what is considered acceptable. No area from this project ends up over 75% of the maximum score, which is a result with very good potential. To validate the indicators, Pearson’s correlation coefficient was calculated. The results show that there is a negligible to a weak correlation between all indicators, except KA & STA which has a strong correlation.

For an HTDH area to be relevant for conversion to LTDH, the qualitative context of the area should be suitable, and the secondary side should be able to be supplied with lower temperatures. Furthermore, there should be an opportunity for increased system capacity and finally, a conversion should generate an economic benefit. The application of the indicator system is an efficient and uncomplicated approach that makes it possible to identify areas that have the potential to develop district heating in a more sustainable direction. It is also possible for stakeholders to subsequently modify the indicator system if desired. In the longer term, the indicator system is an incentive for new business opportunities, increased energy efficiency, and increased economic benefits.