The present document summarizes the activities within work package 5 of the H2020 TEMPO project, focusing on the intermediate results of the innovations packages in the monitoring seasons 2019-2020 and 2020-2021. The TEMPO innovation packages are demonstrated in two sites, in Italy and Germany.
Demonstration site 1: The network in Brescia is heated by a waste-to-energy plant (~70% coverage), residual heat from industry and CHP, and peak-load gas boilers. The A2A network in Brescia currently operates at temperature levels of 120/60°C. In January 2020, the local supply temperature in one branch of the network was lowered progressively to around 92 °C in order to analyses the direct effects and to implement different TEMPO innovations.
First results show reduction in return temperatures (around 1.5 K on a daily average) at the expense of a small increase in thermal demand, leading to an overall increase in primary energy demand. However, limited testing time was available due to the requirements for creating training data for the controller, and further tests are expected to improve the results.
In the next steps, the controller will be refined using the generated data and optimized combinations will be further tested. Further testing will also include additional buildings previously not considered. The testing schedule for the next season will consider the necessity to test each technology in a range of outdoor temperatures as possible in order to obtain comparable data. Where some of the previous tests could only be carried out during working hours, this should make more significant improvements possible. The corresponding effects will be reported in the next report.
Demonstration site 2: a new district heating network in Windsbach (Germany) is heated by a biogas plant, biogas CHPs and a backup gas boiler. The main TEMPO innovation is the implementation of decentralized buffers, which aims at reducing the peak load, thus allowing pipe dimensions to be reduced.
One of the main challenges was the much higher return temperatures than expected due to
a) ongoing optimization of the capacities and control parameters of the decentralised buffers,
b) the local activation of a temporary bypass during winter to avoid freezing (solved) and
c) few faulty buffers that were physically not able to complete their charging process and returned hot water instead (solved)
d) the presence of radiator heating in many buildings,
e) missing hydraulic balancing of the heating system in some of the building installations,
f) the requirement of a multi-family building to have a continuous circulation of 60°C.
As a result, only a few weeks were suitable for proper measurements. It should be noted however, that the measured return temperature with the decentral buffers is significantly lower than in the standard design of ENERPIPE, which foresees a return temperature up to 50 °C (for a supply temperature of 80 °C) for classical radiator systems. As a result, the distribution losses were reduced by 7 %. The reduction in pipe dimensions also results in savings of about 5 % in investment costs.
As an overall conclusion of the first monitoring period, first positive results of the TEMPO innovations were shown in both demonstrators. However, a direct comparison between the baseline and the test periods (with TEMPO innovations) is a challenging task for different technical and operational reasons.
The final results and conclusions are included in the report for the whole reporting period is now available here.