The Future of Microgrid Development & Training

According to the U.S. National Renewable Energy Laboratory (NREL), a microgrid is a group of interconnected loads and distributed energy resources (DERs) that acts as a single controllable entity to the grid. It can connect and disconnect from the grid to operate in grid-connected or island mode. The benefits of microgrids include improved grid resilience, reduced power outages, cost savings, enhanced energy efficiency, and integration of renewable energy.

Microgrids can operate independently during grid outages, providing continued power to critical facilities and communities. By enabling local power generation and energy storage, microgrids minimize the impact of grid disruptions.

Microgrids can also help reduce energy costs by leveraging on-site renewable energy and optimizing energy consumption. They can optimize energy usage and reduce waste by using energy storage and demand response technologies. Microgrids facilitate the integration of renewable energy sources, contributing to a cleaner energy future, and provide a dispatchable renewable energy source for electric utilities and system operators.

Each one of these benefits will improve the overall power quality (PQ) that customers require to control and reduce the cost of operating their businesses while improving the security, quality, reliability, and availability (SQRA) of the power required to run their businesses.

Applications include:

• Critical facilities: hospitals, data centers, and emergency services rely on microgrids for reliable backup power.
• Commercial and industrial sites: businesses, campuses, and industrial plants, improving operational continuity and reducing energy costs.
• Communities and remote areas: communities, especially in remote areas or those with unreliable grid connections. Smart cities can play a vital role in developing smart and sustainable urban environments.

Challenges of microgrids include:

• Regulatory hurdles: They may face regulatory challenges related to grid interconnection, safety standards, and grid services.
• Technical complexities: Managing the interactions between different energy sources and energy storage technologies can be challenging.
• Cost: The initial investment in microgrid infrastructure can be significant.
• Public acceptance: Community acceptance and support are crucial for successful microgrid deployments.

All of these challenges can be overcome by applying new technologies, engineering practices, and installation methods along with a well-trained technical staff.

Given these benefits, applications, and challenges, microgrids will require a specialized technical staff that can install, service, and maintain them in the field regardless of their location — on a hillside interconnected to a transmission grid or behind a data center interconnected to the customer’s power feeder. Providing these critical services is essential to ensure the benefits, meet the application requirements, and tackle the challenges head-on.

This new technical staff will consist of engineers, technicians, installers, and maintenance personnel, among others. Each staff group will require specialized training customized to microgrid hardware and software components, as well as specialized skills related to grounding, PQ monitoring, surge protection, and PQ data analysis, to name a few. Human resources from various energy-related segments can help meet the staffing requirements, but many new technical staff having little to no energy experience will be needed to fill the gaps as microgrids materialize across utility grids and customer sites.

Microgrids and safety

The safety of any system must be top priority to its designers, manufacturers, testers, and end-users. Electric utilities view safety as a top priority when designing, installing, servicing, and maintaining their power systems. The safety of electric utility crews, as well as their engineering and other technical professionals, is vital to their business and the communities they serve. Electric utility power safety programs were designed and implemented based on centralized power generation plants interconnected to the transmission and distribution power system. These systems were designed to support electrical power flow in one direction.

However, with DERs and microgrids interconnected with electric utility power systems and at customer sites, power can flow in either direction. This is because DERs and microgrids serve as energy sources interconnected throughout the transmission and distribution system, including directly on customer property, serving the loads of an individual customer.

The design, manufacturing, installation, commissioning, servicing, and maintenance of DERs and microgrids must properly address the total safety requirements of each microgrid component and the system as a whole. Electric utility workers and technical staff working with DERs and microgrids must be kept safe while doing their work. Ensuring safety for the workforce requires an in-depth understanding of which DER and microgrid sources are energized, when they are energized, and when they must be automatically disconnected when unfavorable electrical conditions that could compromise safety are detected.

Microgrids & power quality

Improving the quality of power (voltage and current) is one of the key driving factors for the development and installation of microgrids. The inherent characteristics and engineered performance of microgrids will improve the quality of power delivered to energy users, but only if careful consideration is given to how microgrid components must be compatible with each other, the grid, and customer loads. Because they can be located very close to customer facilities, they will have significantly reduced exposure to the causes of PQ problems.

Causes include the exposure of power distribution lines to foreign objects — trees, limbs, animals, other objects — and weather events that produce lightning and other disturbances caused by lines interacting with other lines. Reduced exposure to these objects means fewer disturbances (e.g., voltage sags, swells, transients, etc.) will occur, which will lower the risk of malfunctions, damage, and failure of customer power systems and their loads. When a microgrid operates in an islanding mode, disturbances caused by the common everyday grid operations cannot reach microgrid components or the customer’s building electrical system (BES) or loads.

However, because microgrids are made up of physical equipment that takes up space on customer property or in a community close to the customer’s site, they are facing new PQ challenges associated with these environments. Microgrids bring together traditional energy sources such as motor-generator sets combined with new DER technologies such as solar photovoltaic (PV), wind turbines, fuel cells, and other DER systems that use inverter-based resources (IBRs) to convert DC power to AC power. Solar PV, wind, and fuel cell-based DER technologies all use electronics in their inverters for energy conversion (i.e., converting DC to AC) as well as for controlling individual DER systems. Microgrids can also include load banks, which also utilize electronics to control load bank elements and provide their interconnection to microgrids when needed to simulate a microgrid load for testing.

Energy conversion of DC power to AC power for injection into an electric grid and/or customer facility requires the use of inverters, which are large power electronics-based “power supplies.” The inverters in DERs may be a few large single inverter systems to receive combined DC power from hundreds of solar panels or individual inverters on the backs of panels. Regardless of the power capacity of the DER, how DC power is converted into AC power, and where the DER is interconnected to the utility or customer power system, PQ across the DER system, at the point of interconnection (POI), and along the utility circuit is critical to the success of the microgrid.

The use of specialized electronics-based communications systems adds another layer of PQ challenges with microgrids because electric utilities and their customers must be able to actively control each component within a microgrid. Grounding for communications systems first relies on power grounding. Implementing high-performance grounding at the power system level will lower the risk of PQ problems within the communications system. Communications system components must also be well protected against voltage surges, especially since microgrids will be located out in remote areas and near customer sites where the probability of lightning will be higher. Electrical noise must also be very well managed across microgrids to avoid slowing down or interrupting the communications between microgrid components and between microgrids and utility distributed energy resource management systems (DERMS).

Microgrids and PQ/EMC testing

Testing end-use electronic loads for PQ and electromagnetic compatibility (EMC) improves the performance of loads and lowers the risk of malfunctions, damage, and failure of customer equipment. Improved performance means equipment that is less likely to have a problem when electrical disturbances occur. Equally important is customer equipment that is less likely to cause PQ problems within customer facility electrical systems and electric utility power systems. Customized test methods based on what occurs in real-world electrical environments have been developed to determine how electronic loads react to disturbances and poor electrical conditions.

The same applies to microgrids and their components. Understanding the PQ/EMC performance of the individual components of a microgrid is critical. However, understanding the PQ/EMC performance of a microgrid as a complete system, especially when it’s interconnected to an electric utility power circuit or customer power feeder and customer loads, is even more critical. This is because electrical systems as a whole are known to perform differently from their components. Electrical components always behave differently when connected in a system, especially when they are connected to other systems with a higher exposure to electrical disturbances. Understanding how microgrids as a complete interconnected system will require that on-site PQ/EMC testing be carried out as a part of the design and testing of microgrid systems.

In conclusion, the application of microgrids requires not only a diverse engineering and technical group of people but also customized education and training for those doing specific jobs related to the design, manufacture, installation, commissioning, servicing, and maintenance of microgrids. This specialized training ensures the success of DERs and microgrid installations as the world’s electrical load grows.