Store4HUC-Pilot: Parish Church in Weiz, Austria


In the region and municipality of Weiz a lot of experience with renewable energies and EMS are available from various previous projects. In the project Store4HUC, the focus of the demonstration site will be on the integration of a thermal storage for the church on Weizberg, which is connected to the public district heating grid. A group of local stakeholders was identified to observe and support the project. They are for example technical experts in different fields, local authorities or members of the biomass network. The technical experts for example will help W.E.I.Z. and the regional actors to check the installations progress and perform final verification. With the members of biomass networks an intense knowledge transfer is planned. The goal is, that at the end the project team as well as every external stakeholder should enrich their expertise by the participation in a deployment desk.

The parish church in Weiz

Description of the Pilot

Within the project Store4HUC a thermal storage will be implemented in the parish church of Weizberg which is connected to the public heating grid. The parish church is located on a hill in the historic area of Weiz. The history of the parish church goes back to the 11th century, when the church on the "Himmelberg" was popular for pilgrims. In this time, it was a three-nave Romanesque basilica with a two-storey east tower. The basilica was enlarged in the mid-14th century by the addition of a choir. As the only windows have been hatches under the roof, it was very dark in the church. Various attempts to renovate the church and to improve the lighting conditions failed, which is why the dean decided to build a new church in the 18th century. This church is on the Weizberg, on a hill in the north of Weiz. With date of 6 December 2017, the church, was raised to the Basilica Minor, making it the fifth church in the Diocese of Graz-Seckau, which has received this title.

Location of heating system and planned storage

The biomass heating plant Weizberg has been operated by 24 innovative farmers for 20 years (founded in 1999). Through the use of regional wood chips, the added value remains in the region. The heating plant supplies a total of 12 objects on the hill of Weizberg, including the elementary school as well as some commercial enterprises and residential buildings. Using renewable energy, the guiding principle of the farmer cooperative "Energy from the region for the region" is completely fulfilled in regard to the following rough figures:

  • Heat consumption: Max. 812 kW / 1.200 MWh/a
  • Wood chips consumption: About 1.500 loose cubic metre per year (100 % wood chips from regional farmers)
  • Heat plant: 300 kW and 540 kW biomass boilers with rotation combustion

Furthermore, the comfort in the individual rooms should be increased. Through the installation of a building management system, visualisations and the continuous recording of measured values, the plants should be able to be optimized in retrospect by evaluating this "historical data". Moreover, the reduction of the return temperature to the biomass district heating is also a huge target, and if it is possible a new thermal storage with a volume of about 38 m³ will be installed. 

The parish church of Weizberg, which is under monumental protection, is connected to a district heating grid with a heating load of about 220 kW. The heating station with its four separate transformer stations is located close to the church. Only regional biomass is used as fuel. In course of the project Store4HUC new regulations, heat exchanger, thermostatic valves and a monitoring system will be installed.