Remote measurement and control systems in District Heating
The operation of smart heat energy networks now requires the extensive exchange of information and data between parties interconnected in the energy system. Such an interconnection is the thermal substations of consumers in district heating networks. Thermal substations are the interface between the distribution network and the heating systems of interconnected consumer buildings.
In the past, even to date, measurement downloads were collected one or more times a year. Today, the technology available for smart metering and control allows automatic reading of the readings by the energy integrators and the programmers, thus minimizing the cost of taking hourly metering data.
In the district heating systems, faults and discrepancies occurring in the consumer thermal substations are transferred directly to the thermal power plant (transmission and distribution pumping stations as well as thermal power plants) directly through the distribution network.
In order to avoid additional costs for both consumers and thermal energy supply and distribution operators, smart metering and control are required in the thermal substations that incorporate the capabilities to detect and record errors and deviations. Optimization of plant operation is not possible if the measurement of operating parameters is not available.
Necessity and goals
The ultimate goal is to substantially improve the energy performance of district heating installations. The energy efficiency of networks, on the one hand, ensures their viability and, on the other hand, makes them a competitive and attractive option for end-users.
Improved energy efficiency of district heating installations will allow installations:
- to reduce their operating costs
- to ensure surplus thermal power for their further geographic development and the provision of new energy services.
Increasing energy efficiency and better utilization and use of available thermal power are a preferable option to the alternative of continuous upgrading of distribution and transmission pipelines, as well as pumping capacity and thermal energy production capacity, saving operators considerable investment capital.
Without frequent measurements – and preferably on an hourly basis – district heating plants are not able to know where and how improvements can be made to their systems. They are also unable to evaluate the results of the actions they take.
Improving the energy efficiency of systems and operating them as close as possible to their optimum limits requires continuous monitoring and improvement in all segments as well as all installed thermal substations that interconnect end-users. To do this, they need to know exactly what is happening in their networks – especially in the critical places – in real time. Taking remote measurements and checking is the only way to ensure the above. Today it is provided by smart metering technologies.
Advantages of using smart technologies to remotely measure and control
To date, the main reason for taking energy measurements was the need for operators to charge end-users based on their energy consumption. This was usually done with on-site visits, or road crossing outside the connected buildings, and remote metering from a short distance without the end users being disturbed. Furthermore, these data were manually transferred from the staff to a central computer system – usually unconnected with the accounting department – where compliance validation was performed by qualified personnel. These data were generally used exclusively for the issue of the accounts.
However, the measured data can be used much more efficiently and mainly preventively and diagnostically for the operation of facilities. The availability of today's economically feasible smart metering and control technologies – is able to provide significant added value to existing infrastructures.
Remote Measurement and Control gives district heating facilities the ability to have a detailed picture of the actual distribution network status by providing accurate flow and temperature information combined with additional measurements such as differential pressures on strategic sections of the network. In this way, plants are able to solve and solve issues that are extremely important for their operation, such as high return temperatures or excessive average flow rates, ensuring significant energy savings for themselves and their customers.
The application of automatic measurement systems allows continuous monitoring of temperatures in district heating networks. In this way, plants are able to determine whether their systems can operate at lower feed-in / return temperatures, thus improving overall energy efficiency. Low operating temperatures in district heating plants entail higher energy efficiency, lower energy losses, but also the involvement of the end-user.
Frequent reception of metering data also provides additional benefits. Facility operators are able to issue billing accounts more often, on a monthly basis, for example, thereby improving their financial cash flow, allowing for the smooth implementation of their investment plans.
It also provides the ability to quickly and accurately detect faults in consumer thermal substations by facilitating pre-maintenance and recovery planning by minimizing costs and reducing energy losses.
Final User Participation
End-user participation is crucial and essential to achieving a balance of energy supply and demand. Intelligent measurement technologies allow plants to focus on consumer groups with low energy performance by providing incentives for improvement. Low-level energy behavior (unnecessary over-consumption of energy) puts pressure on the distribution networks of district heating leading to their limits. At the same time they have a significant impact on the overall system.
However, encouraging end-users in this direction and improving their energy consumption profile is not an easy task and requires operators to take on the advisory role as well as incentives and disincentives in this direction.
Remote Measurement and Control with data analysis applications allows the creation of a new interactive environment with the end user. It also improves the credibility of operators and improves the level of confidence of final consumers towards energy providers. The latter, using the above-mentioned tools, are able to play their role as energy consultants and to expand the service to end consumers. Preserving and delivering historical energy consumption data to users can contribute to them in conjunction with cost savings.
The European Union has recently placed energy consumers at the center of their power and an obligation for operators to access tools that will help reduce energy consumption and improve the energy profile of users.
Alternative ways of charging are also another way of motivating end-users. For example, pricing may depend on profiles and levels of energy consumption combined with the time it occurs (peak period) by providing discounts or charges.
Pricing problems – Alternative choices
Thermal energy billing for long periods (3 or 4 times per session) leads to the issuance of large bills for final consumers as a rule. It is one of the reasons (among others) that in the end the operators of the district heating plants are unable to collect the debts and at least recover their operating costs. Until now, system operators have historically required the payables of building managers – who are always at risk of unpaid individual consumer debt.
Applying a pay as you go system can ensure a fair and accurate charging system while also transferring the risk of default to the service provider. The use of wireless technology (such as wireless GPRS) allows remote remote management of units and interruption of heat supply in case of overdue debts. The rationale for this pricing is combined either in individual thermal substations units at apartment level or even in the case of centralized substations with pre-paid cost of thermal energy (based on historical data).
Adaptation to European Legislation
The European Union has recently revised the Thermal Energy Measurement and Charging Regulation, which was incorporated as part of the European Energy Efficiency Directive. In particular, the European Commission has updated the guide on the implementation and control of feasible costs for the installation of thermal energy meters in existing buildings connected to energy networks of district heating.
In this context, the existing software tool for the Heat Metering Viability Tool developed by the Department of Energy and Climate Change has been reviewed. This tool is used by thermal energy providers to check whether upgrading / rebuilding of the thermal energy meter on the final consumer side is economically viable for their installations.
According to the regulations, the meter must be located in the heat exchanger at the building or at the point of entry of the district heating network pipelines in the building. There is also a continuing obligation to ensure the continuous operation, proper maintenance and periodic inspection of errors by the heat supplier.