Why does GCP matter?
A grid connection point is crucial for both power generators and the end consumers and represents the interface between consumers’ assets and the broad grid network. It is the juncture where consumers are linked to the public grid, encompassing both low-voltage and mid-voltage levels, serving as the vital interface between end-users’ assets and the broader electrical distribution network. This critical point ensures the seamless exchange of electrical power to the grid and consumers, facilitating the flow of electricity for various applications and purposes.
GCP can be categorized into two primary types, managed by different entities within the energy grid infrastructure.
Types of grid connections
In Europe, high-voltage (HV) connections typically refer to electricity systems operating at voltage levels ranging from 10 kilovolts (kV) to 380 kV, which are overseen by Transmission System Operators (TSOs). These connections primarily manage the transmission of power from large generation facilities with a net capacity exceeding 100 megawatts (MW). HV connections are further classified into three.
Maximum voltage (transmission voltage): these connections are designed for the long-distance transport of electricity in high-voltage transmission lines and connect large power plants (including coal, gas, pumped storage, hydro and wind power plants) and substations (nodes to subordinate grids) to the grid.
High-voltage connections: they are used for electricity transport in transmission lines, ensuring efficient distribution across regions. They connect medium-sized power plants (for example coal, gas, pumped storage, hydro and wind power plants) and substations (nodes to higher and lower-level grids) to the grid.
Mid-voltage connections: they serve the dual purpose of supplying power to both high-consuming industries and, in some cases, electric vehicle charging stations for e-mobility purposes, while remaining less common for the latter. They also connect small-scale power plants (such as gas, pumped storage, hydro, wind and solar power plants) as well as substations and transformer stations (nodes to higher and lower-level grids) to the grid.
A low-voltage connection pertains to the part of the distribution grid managed by Distribution System Operators (DSOs), typically consisting of local and regional energy distribution networks with voltage levels ranging from 250 to 400 volts (V). These connections play a crucial role in integrating renewable energy sources, supporting electrification, and empowering consumers with distributed energy resources. Typically, this is where consumers, including households and charging sites, are seamlessly linked to the grid.
GCP for different renewable energy sources
In the context of photovoltaics, a grid connection point refers to the specific location where a photovoltaic system is connected to the electric grid. This connection point enables the solar energy generated to be fed into the grid, allowing the excess energy to be distributed and used by other consumers within the electrical grid, (if storing locally is unavailable).
The GCP serves as the interface between the solar power system and the broader electrical grid infrastructure, facilitating the transfer of solar-generated electricity to the grid, and vice versa when the PV system isn’t producing enough power, such as during night-time or cloudy periods.
The grid connection point in wind energy has a critical task in ensuring a stable and reliable electric grid. Through load flow and contingency analysis studies, the GCP allows for a comprehensive examination of how wind generation affects voltage variations under normal operating conditions and during contingencies.
In particular, wind generation impact studies conducted at the GCP identify the essential reactive power support levels needed from wind farms, including the determination of various control modes (voltage, droop, or constant power factor), the required reactive power range, and the potential need for additional reactive compensation devices within the grid system. These measures are essential for optimizing the integration of wind energy into the grid.
Other renewable energy sources
In the case of geothermal energy, hydropower, ocean energy, and bioenergy, a well-planned and strategically located connection to the electrical grid is important for harnessing and distributing the generated power. However, each energy source may present unique considerations. For instance, geothermal energy systems often require proximity to geothermal reservoirs, while hydropower plants are in proximity to water bodies with suitable flow rates. Ocean energy, on the other hand, may require specialized marine infrastructure, and bioenergy facilities necessitate easy access to feedstock sources.
Regardless of the difference, a well-placed grid connection point optimizes the effectiveness of these renewable energy sources and contributes to a more sustainable energy landscape.
Challenges in establishing a new grid connection
The grid connection process, in Germany alone, has grown increasingly complex in recent years, posing challenges for both renewable energy project developers and grid operators.
With the country’s ambitious goals for expanding renewable energy sources, particularly wind and solar power, the demand for grid connections has surged. However, this surge has led to delays and administrative hurdles, making it essential to explore ways to streamline and simplify the grid connection process.
This complexity arises from various factors, including technical requirements, regulatory frameworks, and the sheer volume of projects involving renewable energy sources (RES) in the pipeline. With this, it becomes crucial to consider making the grid connection process for renewable energy more efficient, transparent, and accessible to meet the nation’s renewable energy targets while ensuring the sustainability of its grid infrastructure.
Identify the responsible grid operator
In order to facilitate a smooth and compliant grid connection for their renewable energy projects, producers must first identify the responsible distribution system operator (DSO). While institutions like VDE aim to establish standardized procedures, actual compliance can vary. To proceed, producers often need to manually gather essential data from various sources, such as installation records, which may not involve a CRM system. Once this critical information is compiled, it is submitted to the grid operator.
To enhance this process, standardization and automation are key. This entails the development of standardized procedures and digital tools that enable producers to swiftly identify the appropriate DSO, access necessary data, and submit required documentation, simplifying and expediting the grid connection process. In this context, the initial step of identifying the right grid operator is crucial as it marks the starting point for the subsequent streamlined and automated procedures.
The proximity of a power generation facility to existing grid infrastructure can have a substantial impact. Power generation facilities located near established grid assets can lead to cost savings and operational efficiency by minimizing the need for extensive infrastructure build-outs and facilitating a smoother integration process. This applies to various methods of electricity generation, however, this is particularly relevant to low and medium voltage energy generators like solar and wind farms.
The capacity of a generator directly impacts grid stability, as large generators can disrupt voltage and power balance. It also dictates infrastructure requirements, such as substations and transmission lines, necessitating grid upgrades for high-capacity generators and localized solutions for smaller ones.
Voltage level of the network
High-voltage connections are typically used for large generators, while low-voltage connections are more suitable for smaller, distributed generators. Matching the generator’s voltage with the network is essential for seamless integration.
Existing infrastructure of the network
Upgrading or expanding the grid infrastructure is often necessary to accommodate a new or extended connection. It is key to evaluate the grid’s capacity, load and any potential bottlenecks to ensure a reliable and efficient grid connection.
Grid readiness for Distributed Energy Resources (DERs)
In an era characterized by the decentralization, decarbonization, and digitalization (three Ds) of the energy industry, ensuring grid’s readiness to seamlessly integrate distributed energy resources (DERs) is of utmost importance. This readiness encompasses various critical aspects, including the ability to efficiently connect, control, and optimize DERs, as well as aligning the production and consumption of energy with the broader requirements of the grid. It is an essential step towards realizing the ambitious goal of achieving net zero emissions by 2050.
Capacity at grid connection point
To address the challenge of potential grid connection point overload caused by numerous distributed energy resources, a more comprehensive approach is needed. While the physical grid infrastructure can be expanded or modernized, these efforts are often time-consuming and costly. Even with these physical improvements, the grid connection point may still become overwhelmed due to the sheer volume of energy inputs and outputs.
In such scenarios, an energy management system (EMS) emerges as an effective solution for regulating and optimizing electricity flow. This system operates on a 15-minute optimization cycle, intelligently balancing supply and demand by considering real-time factors such as electric vehicle (EV) charging loads. It ensures that predefined limits are not exceeded within each 15-minute interval, aligning with the billing practices of the distribution system operators (DSOs) who bill peak power consumption.
By dynamically adjusting the power demand of connected devices based on the overall load within the optimization interval, this approach not only minimizes grid fees but also performs peak shaving, helping to reduce the highest demand peaks during each billing period. This holistic strategy harmoniously integrates physical infrastructure enhancements with advanced EMS technology to tackle the challenges posed by the diversity of distributed energy resources, all while ensuring that peak shaving and load optimization are achieved to support grid stability and efficiency.