What makes a grid smart?
For most European countries, the grid as we know it — the electrical power transmission network consisting of transmission lines, transformers, substations and much more — was built in the early 20th century. A century later, it is beginning to transform into something much smarter.
What makes a power grid “smart”? As we’ve seen in other industries, digital technology paves the way for both gathering enormous amounts of important data and taking instant action based upon that data. Sensors are deployed where power is generated, along transmission lines, on electricity meters, even on individual appliances. Communication from the sensors give us a bird’s eye view of generation and consumption in real-time.
Sensors gathering and communicating data is just one aspect. With computers, controls and automation, digital signals are used to automatically trigger actions with little or no human intervention required.
What role do energy storage technologies play?
To keep the electrical grid operating correctly, supply and demand must be perfectly balanced at all times. When they are not, the changes to grid-wide voltage and frequency can cause power outages, malfunctions and even damage or destroy electrical equipment.
When the bulk of power is generated from sources with a constant output (fossil fuels and nuclear), controlling power supply levels is relatively simple. As more renewable generation sources are plugged into the grid, their variability brings new challenges. Common occurrences, such as a cloud passing in front of the sun or a momentary drop in wind, cause a sharp drop in power supply.
The more variability that exists in supply and demand, the more difficult it is keep the grid stable. Demand constantly fluctuates depending on time of day, month of the year and end-user consumption. When clouds cover the sun or when large numbers turn on their air conditioning on a hot day, stored energy is needed to pick up the slack at a moment’s notice.
The bulk of the world’s stored energy — in 2017, approximately 95% — is in pumped hydro power. While this is great for injecting a surge of power into the grid to meet peak demand, the suitable geographical conditions for the technology are not available in every region. More importantly, the moment-to-moment fluctuations of the modern grid require energy storage systems with more flexibility and faster response times.
Recent years have shown that battery energy storage systems (BESSs) are ideally suited for smart grid purposes. When renewable electricity generation surges on windy days or hours of peak sunshine, BESSs charge by drawing the excess power. For sudden drops in supply or spikes in demand, power is injected back into the grid to instantly smooth out fluctuations. Finally, the smart digital technology connecting these networks makes these processes close to automatic.
What are the benefits of combining energy storage with smart grids?
It’s clear that both smart digital technology and energy storage work together harmoniously to increase grid flexibility and stability. But what are the main advantages, and who benefits from them?
For grid operators and utilities, smart grids come with legions of benefits. Electricity can be transmitted more efficiently, systems come back online quicker after brownouts and blackouts, peak demand is lowered and operations and management costs are reduced. Additionally, renewable energy systems with variable output can be better integrated. Recent advances have even seen multiple homes, each equipped with solar panels and battery storage, use smart technology to operate as “virtual power plants”.
End-users and consumers benefit from higher resilience — fewer outages — as well as lowered electricity costs. When they have their own residential energy storage systems, they can be almost completely self-sufficient and even profit by selling electricity back to the grid.
The cost of energy storage technology has finally dropped to a level that makes these residential and wide-scale installation economically feasible — where will it go from here?
Interested in learning more? Sign up to our newsletter for the week’s top stories or join our Energy Storage World Forum Group on LinkedIn with over 12,200 members for industry insights. We also organise training courses, industry events and conferences.