Batteries Get Smart: The Use of Energy Storage Solutions in the Smart Grid

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Homeowners worldwide are embracing renewable energy sources and local power generation to reduce their environmental impact and ensure energy security. Meanwhile, the same technology that provides the power for the smart grid is delivering new alternatives to the traditional power network. With this new era of power management on the horizon, this blog explains how smart grid technology works and investigates some of the applications that can provide key benefits to users.

Distributed Generation

The smart grid is changing how we create and distribute our electricity. New energy production methods allow local generation to become a viable alternative to the traditional network. Instead of relying on large-scale power stations, users can now generate power efficiently at a much smaller scale. These small power plants are known as distributed energy resources (DER) and can use solar, wind, or biomass technologies in a process known as microgeneration.
 
In this new paradigm, consumers remain connected to the traditional power network but become active participants. When demand outstrips their local power generation, the consumer draws power from the network to satisfy their needs. When their requirements are reduced, consumers sell the surplus energy they generate back to the network, reducing their overall costs.

Energy Storage Solutions

As part of this development, consumers install high-capacity batteries on their premises to store the energy they have generated for later use. These energy storage solutions (ESS) require sophisticated battery management systems (BMS) to ensure safe and efficient operation. Once the ESS is connected to the smart grid, data will provide the vital link that allows the grid to control how the batteries are utilized.

Microgeneration is an investment for the individual user, supplying energy to the wider grid to reduce their overall costs. However, the utility company responsible for the grid must retain control. For example, there will be no need to draw upon the user to supply energy at times of low demand. Here is where we see just how vital data is for the management of the grid. The data link between the grid and the user controls how much, if any, the grid will take energy. There is also a safety consideration. If work is undertaken on the physical infrastructure, it is hazardous to transmit power. Therefore, the grid controls the flow of energy, and reliable data sharing again becomes critical to this process.

Virtual Power Plants

As more energy users become energy providers, generating energy locally and storing it in an ESS ready for use by the grid, the concept of a virtual power plant (VPP) becomes attractive. A VPP comprises several independent renewable energy generators linked to a single power plant controlled by a central control system. It is virtual because renewable energy sources are physically separated and operated by independent owners who combine their output.

One of the largest VPPs currently running in Europe connects the electrical output of around 1,400 independent power producers, giving a total capacity of over 10,000MW.(1)  All are controlled remotely and integrated into the smart grid. The central control provides the utility company with a large and reliable energy source they can call upon as needed. For the generators, the VPP delivers economies of scale, allowing the users to communicate with the grid collectively, maximizing their profits and keeping energy prices low for consumers.

Resilience for Medical Applications

There are also applications in which a reliable source of energy is critical to safety. Hospitals have long been installed with backup power supplies to ensure continuity in the event of outages. These are usually conventional generators powered by fossil fuels. However, large generators can take as much as two minutes to start. For surgeons, these could be the most critical minutes of a complex operation.

Beyond the operating room, a reliable power supply is vital for ongoing care. More than 2.5 million patients depend upon critical medical equipment in the US alone,(2) a situation repeated worldwide. In the face of this demand, an ESS provides resilience and rapid response. Battery management systems monitor the demand constantly and are ready to provide power in fractions of a second, ensuring a clean and constant supply of energy in the event of an outage. The instant response of an ESS, controlled by the smart grid, plays a huge role when power supply resilience is of critical importance.

Electric Vehicles as Mobile Energy Storage 

The smart grid will also incorporate mobile energy storage in the form of electric vehicles. Employing the same technology in the form of Lithium-Ion batteries as static ESS, electric vehicles are becoming a common sight on our roads. Despite the new power source, personal vehicles share the same usage pattern as conventional cars, spending many hours stationary in car parks or outside homes. Connected to wall-mounted charging stations, these mobile batteries become part of the power network, a technology called vehicle-to-grid (V2G).

As ESS devices, they play a dynamic role in managing energy controlled by the smart grid, acting as a potential energy source at times of high demand. This use case is not limited to domestic cars. Many organizations are transitioning their fleets of vehicles to electric power that remains static for much of the day. School districts worldwide use buses to transport students to and from home, but their use is limited to a few hours per day. They are stationary in the school parking lot the rest of the time.

The batteries that power these vehicles constitute a sizeable VPP that can be utilized both as an energy source during the school day and as a potential resource for the smart grid. Oakland, California, has recently introduced one of the first all-electric school bus fleets in the US.(3)  The 74 vehicles will reduce pollution, creating a healthier student environment. When not in use, the buses provide the storage capacity for a VPP that will supply 2.1 gigawatt-hours of electricity to the Bay Area power grid, enough energy for several hundred homes.

Conclusion

Energy storage systems are poised to form an essential element in the power grid of the future, providing a source of energy that is ready at a moment’s notice. The smart grid combines high-speed data connection with the latest power generation and storage technologies to meet the challenges of modern electricity demands and ensure a resilient and sustainable energy future.

(1)Virtual Power Plants: What are they and what are their advantages for renewable technology?, March 13, 2020. https://actionrenewables.co.uk/news/virtual-power-plants-what-are-they-and-what-are-their-advantages-for-renewable-technology/#:~:text=The%20biggest%20VPP%20currently%20running,capacity%20of%20over%2010%2C000MW. 

(2)“Why Energy Storage is Vital for Healthcare,” Power Sonic, https://www.power-sonic.com/blog/batteries/why-energy-storage-is-vital-for-healthcare/.