April 12, 2023

Substation Engineering for Renewables

An Engineer's Perspective on Best Practices
Image of several electrical lines meeting at a substation. Image of several electrical lines meeting at a substation.

The future of renewable energy is today. As more states pledge to reach net-zero emissions, the need for clean energy is increasing. However, building a renewable energy project is no easy feat, including the complex substation, transmission, and distribution network it requires to distribute renewable energy – wind, solar, green hydrogen, and other carbon-free generation – to homes and businesses. 

The complexities of renewable energy projects require the expert guidance of substation engineering to support the success of the project. From designing and building the substation to maintaining and upgrading it, substation engineering plays a vital role in ensuring the project is efficient, reliable, and cost-effective. In this article, we'll explore a substation engineer’s perspective on the best practices for substation design, importance of substation engineering for renewable energy projects, and value of working with experts in the field. 

The role of collector substations in renewable energy projects 

A collector substation is designed to collect and deliver the power generated from renewable energy and acts as the link between power generation and the electric grid. It is responsible for transforming the electricity generated from wind turbines and solar panels to high voltage levels that are suitable for transmission from point A to B. Collector substations ensure that the electricity transmitted is of the right quality and voltage level and that any excess power is fed back into the grid.  

Collector substations are not just responsible for the transformation of electricity; they also protect against electrical faults, such as short circuits and overloads. This is achieved through the use of protective relays, which detect and isolate faults before they can cause significant damage to the equipment or the power grid. They also have systems that allow operators to remotely monitor and control the flow of electricity through the substation.  

Substation Design Considerations  

When designing a substation for a renewable energy project, there are several factors to consider.  

1. Type and Capacity of the Renewable Energy  
The type and capacity of renewable energy will determine the substation size and configuration needed to step up the voltage to a level suitable for transmission. 

2. Substation Location  
Substations should be located as close to the renewable energy as possible to minimize losses from transmission. It is most efficient to have it placed in a central location for easier circuit connection and delivery of electricity. Next, the substation requires careful consideration of soil types and drainage. The soil must be able to support the weight of the substation and provide stability for the substation equipment. As water accumulation around the substation could lead to equipment damage or failure, the site should be in an area with good natural drainage or have a drainage system in place. 

3. Local Regulations and Standards for Substations  
Local substation regulations and standards are in place to make sure the substation is safe, reliable, and meets the requirements of the local grid operator. Working with experts who are familiar with the local regulations and standards ensures the substation meets all the necessary requirements. 

4. Environmental Impact of the Substation  
Finally, the substation should be designed in a way that minimizes its impact on the environment, such as using low-impact construction techniques and selecting locations that minimize disruption to wildlife habitats. 

Substation Upgrade Considerations 

As renewable energy technology advances and the demand for clean energy increases, it's important that substations are upgraded to meet the changing requirements. 

Upgrading a substation can involve replacing, adding, or modifying equipment to improve efficiency and reliability with features such as protective relays or monitoring systems. These upgrades can improve the safety and resiliency of the substation, reducing the risk of equipment failure and electrical faults. 

One of the most common reasons for upgrading a substation is to increase its capacity. As more renewable energy is added to the grid, the substation may need to expand to accommodate the increased power flow. Upgrading the substation can also improve the transmission and distribution systems' efficiency, reducing losses and improving the system's overall reliability. 

Substation Engineering Challenges and Solutions  

Designing substations for renewable energy projects can be challenging due to the unique requirements of each project. Some of the challenges and solutions include: 

  • Intermittency: Renewable energy, like wind and solar, are intermittent, meaning their power output can fluctuate depending on factors such as weather conditions. The common solution to intermittency is to build a hybrid project paired with battery energy storage systems. By incorporating energy storage, excess energy can be collected and distributed during times of low generation or high demand.  

  • Location: As mentioned earlier, the location of the renewable project can impact the design of the substation. For example, if the wind turbines are in an area with surrounding flood risk, the substation design may need to be raised above the harsh flood-risk environments. The best location for the substation can be determined through hydrology modeling consultations with a water resources expert. 

  • Safety: Substations are potentially dangerous environments, and safety is a critical design consideration. The equipment should be designed to meet safety standards, and proper training and procedures need to be in place for anyone working on or near the substation. Partnering with an engineering firm familiar with the local regulations and standards makes certain that the substation meets all the necessary safety requirements. 

The Future of Substation Engineering 

Substation engineering is an ever-evolving field, and new developments are constantly being made to improve their efficiency, reliability, and safety. Some future developments include: 

  • Smart grids: Smart grids use advanced technology to monitor and control the flow of electricity through the grid, which can help reduce losses and improve the efficiency and reliability of the system. 

  • Energy storage: As mentioned, energy storage systems, such as batteries, can help address the intermittency of renewable energy by storing excess power for use during periods of low power output or high demand. 

  • Advanced monitoring systems: Advanced monitoring systems can help detect and diagnose faults in the substation, while reducing downtime and maintenance costs. 

The Value of Working with Experts in Renewable Energy 

Complex substation design for renewable energy projects requires skill and experience. Substation engineers have the knowledge and expertise to design reliable substations which maximize performance and meet the unique requirements of each project.  

Our experienced substation team can build modern designs and innovative upgrades on large-scale greenfield projects and existing infrastructure. By designing and building the substation correctly from the start in collaboration with experienced professionals, you can reduce the risks of equipment failure and redesigns, minimizing downtime and lowering the overall lifetime cost of the substation. 

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