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Empowering Smart Grids: The Role of MQTT in Advanced Power Flow Control

by Shashank Sharma
20 min read

In an era where the global energy sector is transitioning towards sustainability, the ability to efficiently manage the flow of electricity across an increasingly complex grid has never been more important. Advanced Power Flow Control (APFC) systems, which enable precise management of electrical flows to enhance grid efficiency and reliability, are critical in this transition.

An important element in the implementation of APFC technologies is MQTT, a lightweight publish-subscribe messaging protocol designed for the fast, reliable transfer of information between numerous devices in large-scale networks.

This blog post discusses APFC in detail and highlights how an MQTT platform enables Grid Enhancing Technology (GET), which I had introduced in my previous blog. 

Recap on Grid Enhancing Technologies (GETs)

Simply put, GETs maximize electricity transmission across the existing electrical transmission system. Adding these technologies helps an electrical transmission system to continue connecting to clean, renewable energy like solar and wind to decarbonize the grid while meeting its energy demands. 

The GETs can be briefly classified into the following categories:

  • Dynamic Line Rating (DLR) 

  • Advanced Power Flow Control

  • Topology Optimization

  • Energy Storage Integration

Why are GETs Beneficial? 

Because GETs can quickly enhance existing power grid infrastructure, they also save money and avoid the complexity of building new transmission lines. 

According to the Department of Energy report of the U.S. government, the sum of real-time congestion cost among major U.S. electrical utility system operators in 2016 was $4.8 billion. The congestion costs for 2022 are estimated to be $20.8 billion. Congestion costs for energy utility providers refer to the additional expenses incurred when the demand for electricity exceeds the available transmission capacity in a part of the power grid. This trend highlights a need for optimizing costs without requiring huge infrastructure investments.

To enable these technologies, grid operators and decision-makers often rely on sensors, smart meters, and monitoring devices that collect real-time data, helping them make informed decisions and respond quickly to grid changes.  

Advanced Power Flow Control (APFC) 

Typically, power flow controllers are commonly used in electrical transmission networks. They can be defined as hardware and software used to push or pull power, helping to balance overloaded lines and underutilized corridors within the transmission network. 

An advanced power flow controller is a device that can increase or decrease power flows on a circuit. Let’s understand some common challenges to electricity flow in Alternating Current (AC) networks to understand how increasing or decreasing the power in an AC circuit to the right amount is not trivial. 

Physical Challenges for the Flow of Electricity in AC Networks

The need for advanced power flow control is very well-defined in this case study from the U.S. Department of Energy. Typically, the alternating current flow in high-voltage systems depends on network impedance. Here, impedance can be defined as the resistance and reactance a network offers to the flow of the alternating current (AC). This makes electrical power flow routing different from other routing problems such as the routing of an autonomous vehicle or packet routing in a telecommunication system. The electrical power flow always depends on the path of least impedance. For APFC, the advanced controller can inject a voltage in quadrature with the line current to synthesize a capacitive or inductive reactance, thereby increasing or decreasing power flows. 

An additional challenge in optimizing electrical power flow is the limited option to store electricity, unlike a warehouse for common consumer goods. Here, the end user always requests how much electricity they need. This challenge becomes even more complex in the presence of Distributed Energy Resources (DERs).

Complexity Added by Distributed Energy Resources (DERs) 

The increase in production and use of DERs like solar panels and wind turbines has significantly complicated the landscape of electrical power flow. Unlike traditional power generation sources, DERs are often intermittent and decentralized. This decentralization means that power is generated in multiple, often fluctuating, points across the grid rather than at a few stable and predictable sources. This leads to:

  • Variability and Intermittency: Solar and wind energy depend heavily on weather conditions, leading to variable power outputs. This unpredictability makes it challenging to manage the flow of electricity through the network, as the amount of power being injected into the system can change rapidly and frequently.

  • Reverse Power Flows: Traditional power systems are designed for a unidirectional flow of electricity from large-scale power plants to consumers. However, DERs can cause power to flow in the opposite direction, from consumers back to the grid. This can lead to issues such as voltage regulation problems, potential overloads, and even safety risks if not managed correctly.

  • Complexity in Maintaining Grid Stability and Reliability: With multiple points of power generation, maintaining the stability and reliability of the grid becomes more complex. The grid must adapt to sudden changes in power generation and consumption, requiring more sophisticated control strategies to ensure continuous, reliable service.

Risks of Not Implementing APFC 

An absence of advanced power flow control increases the risk of one or more of the following: 

  • Grid Instability: Without advanced controls, the power grid could become less stable, leading to increased frequency and voltage fluctuations. These instabilities can cause damage to sensitive electronic equipment, disrupt industrial processes, and even lead to widespread power outages.

  • Inefficiency and Increased Costs: Failing to optimize the power flow can lead to inefficiencies, such as overloading some power lines while others are underutilized. This not only increases wear and tear on the grid infrastructure but also raises the cost of electricity as more resources are spent on maintenance and less efficient power delivery.

  • Inability to Fully Integrate Renewable Energy: Without the necessary controls, it may be difficult to integrate and maximize the use of renewable energy sources. This can hinder efforts to reduce carbon emissions and meet renewable energy targets, potentially leading to higher environmental and social costs.

  • Economic Risks: The operational risks and inefficiencies can translate into economic risks for utilities and grid operators. These include potential revenue losses from unserved demand, higher operational costs, and potential penalties for failing to meet regulatory standards for reliability and service quality.

  • Safety Risks: Finally, without proper flow controls, there is a higher risk of accidents and safety incidents. This includes the risk of fires from overloaded equipment or failures in safety mechanisms meant to protect the grid and its users.

Implementing advanced power flow controls is thus essential not just for optimizing the use of resources but also for ensuring the safety, reliability, and efficiency of the modern, increasingly decentralized power grid.

Why implementing advanced power flow controls is essential

Here is a simple representation of a grid that does not contain an APFC mechanism. Without that, it can result in grid instability as represented above.

How Do MQTT and HiveMQ Enable APFC? 

In my previous blog post, I explained how MQTT is a lightweight publish-and-subscribe protocol that is specifically designed for such use cases. MQTT also offers an easy way to connect to existing infrastructure, create a standard data layer, and push data to make it available to any cloud or enterprise system. Integrating an MQTT platform into your network does not need heavy hardware investments upfront.

An MQTT Platform like HiveMQ can offer additional qualities that help enable APFC.

Enhancing Grid Stability with Real-Time Communication

MQTT provides a foundation for real-time, reliable communication across a grid. HiveMQ extends these capabilities by offering high availability and reliability that ensure messages are delivered efficiently, even in highly distributed environments like a modern electrical grid.

  • Monitoring and Control: HiveMQ’s MQTT platform is easy to integrate with existing grid infrastructure, enabling more efficient data flow and quicker response times. Its ability to handle millions of messages per second ensures that data from countless sensors and devices, including those in remote renewable energy sites, is processed in real time. Additionally, with the help of HiveMQ Edge, any non-MQTT data can be brought into MQTT protocol by using protocol adapters or SDKs.

  • Predictive Analysis: Beyond simple MQTT functionality, HiveMQ offers integrations with big data platforms and analytics tools, allowing grid operators to perform more sophisticated predictive analytics. This helps anticipate and mitigate the variability of renewable energy sources. Additionally, HiveMQ Data Hub provides mechanisms such as data transformation, data normalization & contextualization, and behavior transformation to define how in-flight MQTT data is handled in HiveMQ Broker. This ensures that data quality is assessed early in the data supply chain, which helps with predictive analysis and other similar data-intensive use cases. 

Optimizing Power Flow

While MQTT supports decentralized power flow control, HiveMQ enhances this by providing more robust and scalable solutions that are critical for implementing Advanced Power Flow Control (APFC) in grids with high DER penetration.

  • Decentralized Control: HiveMQ’s distributed architecture optimizes data routing and reduces latency, which is essential for local adjustments in power flow required by DERs.

  • Scalability and Flexibility: HiveMQ can scale to connect up to millions of devices. As the grid adds new renewable resources, HiveMQ’s MQTT platform can easily meet the increasing connectivity needs. It ensures that addition of new network nodes and increased data traffic do not compromise grid management system performance.

Reducing Operational and Economic Risks

HiveMQ adds layers of reliability and efficiency, reducing operational risks and costs more effectively than what the vanilla MQTT specification offers.

  • Enhanced Fault Detection and Response: With features like high availability and fault tolerance, HiveMQ ensures that communication is maintained across the grid without interruptions, which is crucial for detecting and responding to faults promptly.

  • Cost Efficiency: By optimizing the communication layer, HiveMQ reduces the operational load on grid systems, helping to decrease maintenance costs and extend the lifespan of existing infrastructure.

Securing the Grid

MQTT provides fundamental security features. HiveMQ enhances these with more sophisticated security capabilities tailored to the needs of critical infrastructure like power grids.

  • Secure Data Transmission: HiveMQ supports advanced security configurations including TLS/SSL, and also offers options for integrating additional security mechanisms such as OAuth or integration with enterprise security systems.

  • Configurable Quality of Service Levels: HiveMQ’s fine-grained QoS management ensures that critical messages receive prioritization over less crucial data, which is vital for maintaining grid stability and safety.

  • Granular Role-based Permission for Clients and Administrators: HiveMQ supports client authentication and authorization via certificates, tokens, and usernames/passwords. This allows the necessary communication between the infrastructure to happen securely. Moreover, the security features not only take care of unauthorized client access but also provide secure access features for administrators and other users who may need to access the MQTT broker.

Representation of how MQTT enables APFC to meet the changes in energy supplyThis graphic is a simplified representation of how MQTT enables APFC to meet the changes in energy supply. With HiveMQ Edge and a Broker (which can be fully-managed), HiveMQ’s MQTT Platform enables real-time data collection and access across various assets along the energy supply chain. In turn, this enables real-time data-driven decision-making and thereby APFC.


Adopting HiveMQ in grid management systems brings a transformative shift towards more resilient, efficient, and secure power networks. With its enhanced capabilities over standard MQTT, HiveMQ is particularly well-suited to meet the challenges posed by integrating high levels of DERs in the grid.

For grid operators and energy providers aiming to enhance their systems' reliability and efficiency in the face of increasing complexities introduced by DERs, HiveMQ offers a robust, scalable, and secure platform.  

Stay tuned to our blog as we roll out another post on enabling other grid-enhancing technologies with MQTT. In the meantime, explore HiveMQ Cloud Self-Service to discover how you can use it to develop, test, deploy, and scale production IoT use cases without a substantial investment.

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Shashank Sharma

Shashank Sharma is a product marketing manager at HiveMQ. He is passionate about technology, supporting customers, and enabling developer-centric workflows. He focuses on the HiveMQ Cloud offerings and has previous experience in application software tooling, autonomous driving, and numerical computing.

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