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DEFRAM - A database for facilitating better energy efficiency assessments and improvments

DEFRAM is a project that was funded by the Swedish Energy Agency. The project started on the 10th of December 2012 and ended on May 10, 2013. The project was run at Linköping University and involved researchers from the Department of Energy Systems at Linköping University (Patrik Thollander) and the Department of Computer and Information Science at Linköping University (Eva Blomqvist), and was implemented in close cooperation with the Swedish Energy Agency (Coordinator: Lara Kruse). Project Manager was Eva Blomqvist, Linköping University.


Along with an increased share of renewable supply of energy, increased energy efficiency is the single most important means of achieving sustainability in our energy usage, both locally, regionally and globally. Energy efficiency in industry is, according to the IPCC (2007), the single most important means of preventing global warming. Many studies, both national and international, demonstrate the presence of a so-called "energy efficiency gap", i.e., a difference between what should be implemented according to a rational analysis, when the technology is clearly cost-effective, and what is the de-facto implemented. This "energy efficiency gap" is usually explained through the existence of various barriers to improved energy efficiency, such as lack of time, lack of information about possible technical solutions, management's lack of prioritization of the issue of energy efficiency, etc. In order to overcome these barriers to improved energy efficiency and try to reduce the gap, a broad range of activities in society are required.

Tools for energy audits to be used in national energy audit programs are mentioned as a key component to achieve comparable results that can be used for evaluating, researching, and later improving such programs. It should be noted that a tool can not replace the skill of a competent auditor, when it comes to proposing measures for improvement, but can still be an important support. A "database" that includes energy efficiency measures previously implemented as a result of energy audits is a tool that can assist an auditor when developing improvement proposals and recommendations. Having such a tool means that the effort required from an auditor can be reduced, and it also assists auditors who are not deeply familiar with all the processes in the company. A "database" with previously proposed energy efficiency improvement measures can thus improve the quality of an energy audit, ensure that the actual proposed measure is reliable (by relying on what others have done before), and thus result in a more valid energy audit report. Such a "database" may also be of value to a customer, by enabling validation of offers from energy service companies.

The data required for such a "database" are already freely available, but are not easy to access and use, because they are spread across several organizations and represented in multiple formats. For example, the results of the Swedish Energy Agency's PFE project are available as a downloadable Excel-sheet, while IAC's surveys in the U.S. are available through a search interface on the Web. Today (before the project) there are no connections between these data sources and no way to jointly search the data from different sources, and additionally there is not any simple way to include the data from these sources into software applications.

Vision and goals

The long term vision of the project is to make data on energy audits more accessible, both for application developers and end users, such as auditors. The goal of this project is to make available a number of datasets containing technical energy efficiency improvement measures (found today mostly as downloadable Excel files) as Linked Data on the Web (for more information on what this means see the LOD project). By integrating, i.e., interlinking, these data sets, a user can search in all datasets through a common service (e.g. a SPARQL endpoint) or through any tailor made search interface, or an application that uses the service.

Project results

The project started from three datasets: (1) IAC's (Industrial Assessment Center) database of around 120 000 recommendations (until late 2012), which is by the way the world's largest energy audit program with more than 10,000 energy audits performed so far, (2) results from the Swedish PFE project, from the first program period, and (3) the results of the Swedish Energy Agency's energy audit support, the so-called "energy audit checks" (EKC), during 2011-2012. To demonstrate the user benefits and usefulness in linking these data sources have first created an OWL vocabulary, i.e., a new common data model for the datasets, built as a vocabulary for representing the data elements, and most of the actual data were then transferred to the RDF format, structured according to the new vocabulary.

For interlinking the different data sources a number of manual mappings have been implemented. Among other things, measures were as far as possible reclassified according to a new taxonomy of task types developed by Energy Systems researchers at Linköping University. To integrate IAC data with Swedish data, a mapping was also made both between the IAC's ARC codes (action types) and the taxonomy, as well as between the industrial classification SIC (used by IAC) and the Swedish SNI-2007.

The result of this work is published through a so-called SPARQL endpoint, which provides direct access to the linked data stored in an underlying triple store. In the current release (as of 2013-09), there are about 2,200 Swedish recommended measures published, and 120,000 recommendations from IAC. Access to these data can be gained through an interface for writing your own SPARQL queries, as well as a demonstration interface for end users (in Swedish), where questions can be formulated through various menu options. The complete dataset can also be downloaded as an RDF-dump. Note that a continuous quality control going on, so data can be changed and the project or its participants cannot be held responsible for any errors in the data - the results are used at your own risk. Note also that the result is a demonstration of what is possible to implement, not a full-scale operational solution - we can not guarantee the uptime and response times for the demo service.


For more information, contact the project manager: Eva Blomqvist.

Page responsible: Eva Blomqvist
Last updated: 2013-10-08