Efficient use of district heating boosts cost-effectiveness


Wholly owned by the Danish city of Brønderslev, the Brønderslev Forsyning A/S holding company is responsible for the district heating and water supply, as well as for wastewater treatment.

Brønderslev Forsyning A/S is a pioneer in the field of smart energy and is implementing, among other things, a “District Heating of the Future” concept for the city of Brønderslev.

The utility relies upon its own combined heat and power unit – one of the most efficient plants worldwide due to the combination of solar, biomass and heat pumps – for the generation of power and district heat. Brønderslev Forsyning A/S was thus awarded the 2018 prize for district heating by the Danish District Heating Association for its decentralised combined heat and power plant.

One important component of Brønderslev Forsyning A/S’s intelligent district heating is smart metering. Before the implementation of a comprehensive fixed network solution by Diehl Metering, the Danish utility was unable to record the energy efficiency in its heating network.

Since the old mechanical meters were unable to provide current values on the temperature conditions in the distribution network, it was not possible to efficiently control the forward and return temperature.

Households that do not use their district heating water due to disadvantageous heating behaviours – known as “bad coolers” – have led to very high return temperatures.

Brønderslev Forsyning A/S therefore had to deal with unfavourable (i.e. low) temperature spreads and high return temperatures, and as a consequence the heat produced in the power plant was not used effectively. This meant that both consumer and utility had to bear unnecessary extra costs.

In order to stay true to the ‘District Heating of the Future’ concept, Brønderslev Forsyning A/S decided to implement an innovative fixed network solution for fully automated reading of more than 4600 SHARKY 775 ultrasonic energy meters. In order to provide consumers with intelligent leak protection, the utility has opted for the additional implementation of SHARKY FS 473 ultrasonic flow sensors in each house’s return pipes.

The flow sensors are connected to the SHARKY 775 meters installed in the flow pipe to automatically record and compare the flow rates in the flow and return pipes. Should a value deviate from the predefined range, the ultrasonic energy meter will set off a leak alarm. The SHARKY 775 can reliably detect a burst pipe after just 90 seconds as well as low flow rates, caused for example by a dripping heater.

“This Diehl Metering solution has enabled us to offer our customers an additional security service. Thanks to the regular, fully automated reading of meter data, we can notify our customers of leaks in their houses via email or SMS – if they so wish. This service is well received by our customers because it effectively prevents costly damage to houses”, says Thorkil Bartholdy Neergaard, managing director of Brønderslev Forsyning A/S.

Utilities can monitor and analyse the difference between forward and return temperature (spread) for each consumption meter in the IZAR software by Diehl Metering and thereby optimize the network performance over time.

Because the SHARKY 775 sends all measured values such as forward and return, flow rate, energy consumption and alarms via radio, it provides a solid basis for increasing efficiency as part of a fixed network. Using the meter data management software IZAR PLUS Portal, Brønderslev Forsyning A/S can see the difference between the forward and return temperature (temperature spread) for each meter in an innovative analysis cockpit.

This allows defects, abnormal operating conditions at the transfer stations and disadvantageous consumer heating behaviour to be detected quickly.

In many cases, consultation with the consumer is enough to achieve high temperature spreads and a considerable reduction in the return temperature.

“Because IZAR software enables us to perform smart analyses, we can better adapt heat generation to our customers’ consumption patterns and notify them of disadvantageous heating patterns. This has allowed us to reduce our return temperature from an average of 40°C to 37°C, which corresponds to cost savings of €60,000 per year. We can invest the money saved, directly in our ‘District Heating of the Future’ concept”, Thorkil Bartholdy Neergaard explains.

The Information is provided by Diehl Metering