Over the last decade, operating utilities and distribution grids has become a significantly more complex and ambitious undertaking.
Grid evolution spurs innovation
Key challenges include large-scale integration of variable generation (such as wind and solar), managing different voltage levels, and the ongoing evolution of policies and market structures. All of this introduces additional uncertainties for grid resilience and reliability, says Andreas Luxa, Director Marketing Energy Management, Siemens, who will be presenting at the upcoming European Utility Week. The topic is “Challenge meets opportunity: A comprehensive power distribution with Totally Integrated Power.”
In an exclusive interview with Engerati, he explains that this kind of “grid evolution” spurs immediate innovation in distribution grid technologies — such as intelligent transformer substations, remote monitoring and automatic fault detection.
“Beyond conventional grid development, utilities will need to install additional communication-enabled products and solutions in order to get real-time information about the medium- and low-voltage grid — which is currently not sufficiently transparent.”
Even more complex demands are emerging, especially with respect to grid management and load control. In particular, these application areas are likely to play a major role:
• Peak demand management
• Distributed energy resources integration and management, including energy storage solutions
• Flexible load integration and management
• Grid optimization
Maintaining system stability with the right technologies
According to Luxa, one option for stabilizing the grid is to use an energy storage system as a buffer.
The instant capability of a power grid to rapidly increase power in-feed if additional loads are connected is a key measure of grid stability. However, producers of wind or solar energy usually cannot provide this because of missing spinning reserve.
When energy is supplied to the grid from distributed sources, it can also cause a reversed load flow. In distribution grids not designed for these requirements, damage to equipment and power outages can result.
Luxa points out that this situation is creating a strong demand for energy storage solutions, which can improve voltage and power quality by providing active and reactive power on demand.
Additionally, storage solutions can play an important role in microgrids, to enhance reliability of electrical grids in isolated locations and places where access to power is limited, explains Luxa. Our recent interview, Utilities Should Overcome Their Fear of Microgrids, with Bernd K. Koch, Director, Siemens Microgrid, Energy Automation, expands on the benefits of microgrids.
Energy storage solutions can also help utilities avoid expensive peak loads, while providing a sustainable solution for industrial processes, infrastructure businesses and energy-efficient buildings.
“During low-load periods, energy can be taken from the grid and stored for use during peak load periods. This creates savings for customers as well as utilities, since exceeding the agreed-upon maximum load can result in very high energy bills.”
Luxa points out that secondary substations represent another emerging opportunity for grid stability. “These often have very low-tech communication infrastructure (or none at all), and therefore are seldom monitored or remote-controlled.”
In critical situations, grid operators must be able to respond quickly, explains Luxa. To do this, it helps to equip a utility’s most important secondary substations with intelligent protection systems and control technology — as well as with components that are adjustable and that can be remote controlled.
“One example of this is the latest generation of intelligent medium-voltage switchgear. This offers several advantages, including adaptive protection, extensive automation and multifunctional communication. When deployed at secondary substations, this switchgear can be monitored and remotely controlled — helping to locate faults more quickly. This minimizes outage times and electricity losses, and generally improves the availability of the grid.”
Mission-critical power consumers’ expectations
“Today, you can’t think about sustainable energy supply that doesn’t include renewable energy resources,” explains Luxa. He adds that while the pace of transition from fossil and nuclear power plants towards wind, solar and bioenergy varies from one country to another the general framework for energy supply has already been established.
Of course, deploying renewables on a large scale leads to new challenges for grid stability. Even the shortest interruption of energy supply can lead to a complete failure of production plants — yielding an enormous loss of quality and time, along with noticeable financial costs.
Luxa points out that most industries face diverse challenges, such as managing complex processes, improving energy efficiency, enhancing security and meeting regulatory requirements. “This is where Siemens can help with its integrated, tailored solutions and services to efficiently identify and respond to a wide variety of events that could threaten business continuity or profitability – all in compliance with regulatory requirements.”
Often the complexity of these projects requires in-depth, one-on-one consulting plus consistent, end-to-end planning of systems and plants. Luxa says, “To this end, Siemens has developed special planning tools for dimensioning electrical power distribution systems, and we can assist our customers with a diverse range of support services.”