Energy Management – Provable Results

Customer

The Swiss company Aspiag (Austria SPAR International AG) operates a network of 35 Interspar hypermarkets and 13 Spar supermarkets in the Czech Republic and another dozens of Interspar hypermarkets and Spar supermarkets in Hungary, Slovenia, Croatia and in other countries. We have worked with this customer since 2004, when the construction of hypermarkets was in full swing. Since 2004, all new hypermarkets and supermarkets in all four countries have been equipped with a Domat control system and have gradually been connected to central dispatching in individual countries (hypermarkets and supermarkets) and local headquarters (in the case of hypermarkets).

As part of our long-term cooperation, a standard has been created for furnishing of shops from a measuring and regulation point of view. The document describes standards in furnishing of technology (air handling units, heat sources, chillers, etc.), measuring and regulation, and these standards are part of the tender documentation. Thanks to this approach, the building control system across all facilities has been harmonised, which results in standardised control of technology, measurement of similar variables and the option of their comparison, etc.

Project

The investor, as part of reduction of operating costs, has decided to establish closer cooperation with Domat Control system also in the field of energy management. In the first round, a total of 11 facilities were examined. All of them were of a similar character, and an important role in energy consumption was played by the sales area, where the measured temperature in various markets ranged between 17 and 23 °C. During calculations, the input data were information regarding temperature and heat consumption. For four selected markets, situational indicators were calculated, specifically energy consumption per m² and year, which relatively closely copied these temperatures. In view of the similar character of use of buildings, there was a possible coincidence.

Energy management occurred from June to December 2013 and included two hypermarkets in the northern part of the Czech Republic: Liberec and Česká Lípa. Since from all facilities, data regarding consumption was registered on a long-term basis, the investor and the energy auditor had a sufficient amount of data when deciding regarding deployment of external energy management.

Procedure

The auditor prepared a detailed energy audit for two selected facilities, a supermarket with area of 15,658 m² in Liberec and a similar facility in Česká Lípa. The buildings were classified in energy class D. At the end of the report, there were three variants for implementation of saving measures, including calculation of savings and periods of return.

The investor selected the first variant, which involved only implementation of operating measures, without changes in technology and with practically zero investment costs. During the start of the heating season in 2013, the administration of control systems was transferred under the dispatcher of Domat, and the implementation was supervised by the auditor. The operating parameters were checked on a daily basis by a technician from Domat and configured as needed and based on the auditor’s recommendations.

Results

After four months, savings were calculated for the period September to December 2013. The total achieved savings for the period amounted to 32.5 % of the reference costs, which corresponds to the amount of EUR 11 000. The period until recuperation of invested costs was 52 days. The estimate of average savings during broad application to all other facilities only in the heating scope will range from 17 to 25%. The investor immediately decided to apply the test procedure for other markets, including the cooling season, where the cost savings should be even higher.

Conclusion

This is basically a post-warranty service, for which Domat Control System offers its products. It is also possible to provide it at facilities where a control system of a different brand is installed. It includes integration of the control system into central management station and the ContPort service, which evaluates the measured data. Ideally, the facility will be equipped with heat meters and electric meters, but at least in the testing phase, manual readings and/or invoices for energy consumption are sufficient for analysis. Energy management is closely related to so-called postcommissioning, or subsequent fine tuning of the control system after changes in the use of the building or after several years of operation. A key task for successful economic profitability of the project is minimisation of its costs, and therefore the variant without replacement of technology, but only with expert work with the existing control system, seems very attractive. The replacement of technology will be possible in later phases if it proves to be economically attractive and technically necessary.

Energy management - Case study SPAR