What is Congestion Management?

What is Congestion Management?

Introduction

With the pace of energy transition increasing, grid operators are encountering an increasing number of power quality issues and capacity bottlenecks. These bottlenecks are caused by grid congestion. Traditionally this would have been resolved by reinforcing the physical grid. I.e. building more transformers, installing cables with more capacity. However, the speed at which the energy transition is currently taking place is too fast for this traditional approach. As a result, other solutions which can be deployed quicker are required. Congestion management is one of them.

In this blog post, we will dive into what congestion management is and why is it important. We will also look at how the Withthegrid new analytics feature enables asset managers, maintenance engineers, and inspection personnel to reduce workload, outages and extend asset lifetime. This can be done by using real-time sensor and operational data to monitor the condition of the grid.

What is Congestion Management?

Congestion management steers supply or demand in periods when the maximum grid capacity is reached. This can be due to too much supply (think sunny summer day) or with too much demand (think winter period with low wind). Congestion management can be in a form of direct control, such as the curtailment of excess renewable energy, or in a form of a market-based mechanism, where price signals are used to incentivize grid parties to adjust supply or demand.

Why is Congestion Management Important?

Without active congestion management, the electricity grid will not be able to deal with increasing renewable energy production and increasing electricity consumption. This will lead to more outages, unhappy customers, and a barrier to any economic activity.

As grid operators do not have complete real-time insight into the grid, especially at lower voltage levels, or can completely control anything connected to the grid some parts of the grid will be declared as congested. When a part of the grid is marked as congestion it does not mean there is no capacity at all. It means that based on certain forecasts at specific moments in time there is no capacity. Around this period there may be sufficient capacity as can be seen in the figure below.

Congestion management is a technique that can help utilize network capacity more efficiently while supporting the security of supply to end-users. This way, grid operators can keep the network within operating limits while increasing the share of renewables.

How to monitor Congestion Management?

The importance and dynamics of congestion management shows that managing grid infrastructure is becoming more complex by the day. From an “install and forget” approach to an “upgrade, monitor and manage” requires a different operational model and different tools. The challenge is even bigger when taking into account the general aging of the electricity grid which was built mid-20th century leading to more outages, issues, and inspections. Additionally, the availability of technical personnel to resolve these issues is decreasing. There is an aging technical workforce and there are more open jobs than skilled technical labor available.

Monitoring and implementing congestion management starts with having real-time insights into the performance of the electricity grid. Analytics and THE internet of things play a pivotal role. Below is an example of how to implement this.

Example of congestion management

Let’s use an example to show how congestion management can be applied:

1. We have a region in Utrecht with 3 lower voltage transformers.
2. 1 transformer is predicted to experience congestion in the next 24 hours due to too much solar generation
   • Estimated 0.5 MWh between 1-3 pm
3. Behind this transformer are households and businesses. 3 businesses have been identified to have some flexibility to increase their consumption:
   • Small office 1: 0 – 0.2 MWh
   • Small factory 2: 0 – 0.5 MWh
   • Office building 3: 0 – 0.3 MWh
4. The grid operator can do 2 things now:
   • Provide a market incentive (i.e. price) to manage congestion with the help of the businesses that offer flexibility
   • Based on bilateral agreements curtail excess solar energy

Using Withthegrid Analytics, we can monitor that transformers are overloading during the day. We devise a strategy to curtail solar between 1-3 pm because no flexibility is available. We then monitor whether the transformer is not overloading anymore with this new strategy. With Withthegrid both the outcome and the process are tracked in real-time. The asset owner is in control, achieves its ROI, and maintains its license to operate.

Withthegrid Analytics

At Withthegrid we believe asset management for electricity grids needs to be simplified. Only in that way complex themes such as congestion management can be realized. The analytics feature is a core part of that. It enables asset managers, maintenance engineers, inspection personnel to create their own dashboard with custom queries. In this way, their own internal KPIs can be tracked based on real-time sensor and operational data. Such a feature allows for custom dashboards that are used and tailored to support congestion management.

By connecting more smart meters at the critical locations, upgrading transformers to smart substations, operators can see in real-time how much spare capacity is still available, and in situations of peak generation, can respond to these signals by curtailing just a minimum amount of energy. The Withthegrid analytics functionality allows aggregation of monitoring devices and analysis. It is a strong tool that gives users the power to improve the monitoring of assets not only on the component level but more importantly on the system level.

Summary

The key take-aways for congestion management are:

• Congestion management allows for more efficient use of available network capacity
• It mitigates the need for unnecessary grid investments and allows grid operators to keep up with energy transition
• Deployed with direct control methods (bilateral-based mechanism such as curtailment or peak shaving) or market-based methods, or a combination of both
• There are 2 types of congestion:
  • Congestion due to overproduction (increasing PV penetration)
  • Congestion due to overconsumption (electrification)
• It is important to monitor assets in real-time to make us of congestion management