Understanding Energy Storage Systems – New Trends in Technology

Electricity in its original form cannot be stored on any scale, but with the use of an Energy Storage System (ESS), it can be converted to other forms of energy that can be stored. These forms of energy can later be reconverted to electricity when needed.

An ESS provides a wide array of technological approaches to managing our power supply in an effort to create a more resilient energy infrastructure and bring cost savings to both utilities and consumers. Current electricity storage system technologies include batteries, flywheels, compressed air, pumped hydro storage, and others. Today, all of these systems are still limited in the total amount of energy they can store, but research continues to improve these technologies at a rapid pace.

The US electric power grid is based on a delicate balance between the electricity supply generated and consumer demands. An effective way to help balance fluctuations in electricity supply and demand is to store electricity during periods of high production and low demand, then release it back to the grid during periods of lower production or higher demand.

In this issue, we will discuss how electricity storage provides reliability, economic, and environmental benefits. Depending on its deployment, electricity storage could help the US power grid operate more efficiently, reduce the likelihood of brownouts during peak demand, and enable more renewable resources to be utilized.

Growing Need for Electricity Storage

Since the discovery of electricity, researchers and scientists have sought effective methods to store energy for use on demand. Over the last century, the energy storage industry has continued to evolve and innovate in response to changing electricity requirements and advances in technology.

Today, US consumers use electricity 24 hours a day. Whether awake or asleep, the need for electricity is continuous. Many people take for granted how easily they can access the energy required to power devices, appliances, tools, machines, vehicles, and more.

Now, the rapid acceptance of electric vehicles is putting additional pressure on the power grid. Furthermore, advancements in renewable energy markets—such as solar and wind—are significantly increasing the need for energy storage, given their substantial impact on the grid.

Energy Storage Technologies

The electric power sector generates a relatively fixed amount of electricity over short periods, while demand fluctuates throughout the day. Developing technologies that store electrical energy for future use represents a significant shift in electricity distribution.

Energy Storage Systems

Energy storage systems (ESS) are designed to manage the power required to supply customers at peak times. They will help make the integration of renewable energy into the distribution system smoother and easier. ESS also helps balance microgrids, achieving a stable balance between generation and load. These systems provide frequency regulation and support high-tech industrial facilities, contributing to a more reliable power supply.

High Voltage Power Electronics

High voltage power electronics, such as switches, controllers, and inverters, allow electric power to be rapidly and precisely controlled. These devices help the system operate efficiently and respond quickly to disturbances. Efforts to reduce the cost of energy storage technology and power electronics are ongoing to ensure faster market acceptance.

Reaching the Goal of Net-Zero Carbon Emissions

The Long Duration Storage Shot (LDSS) target is critical to achieving net-zero carbon emissions from the electricity grid by 2035 and across the economy by 2050. Energy storage increases local control of the power system and enhances resilience, especially for communities facing frequent power disruptions or limited access to the grid.

With falling costs of solar and wind technologies, the share of variable renewable energy will continue to rise. Energy storage is essential to accommodate this variability while ensuring uninterrupted output. The integration of renewables into end-use sectors highlights the crucial importance of electricity storage in achieving deep decarbonization.

Energy Storage Systems Technology

ESS offers a wide range of technological solutions for managing power supply and building resilient energy infrastructure, reducing costs for utilities and consumers. Below are the various approaches currently being deployed worldwide.

Battery Storage

Since Alessandro Volta invented the first battery in 1800, scientists have expanded our understanding of electricity. At its core, a battery is a device containing one or more electrochemical cells, where chemical reactions produce a flow of electrons, creating electric current. Advanced chemistry batteries, flow batteries, and capacitors convert stored chemical energy into electrical energy.

Types of Batteries

All batteries have a cathode (positive side), an anode (negative side), and an electrolyte that chemically reacts with them. Common rechargeable batteries today include:

• Lithium-ion batteries
• Lead-acid batteries

Supercapacitors

Capacitors store electrical energy on two metal plates separated by a semiconductor. Supercapacitors, used in energy storage systems requiring frequent charge-discharge cycles, have evolved with special electrodes and electrolytes. They charge and discharge quickly, making them suitable for applications such as electric vehicle charging.

Mechanical Storage

Mechanical storage systems rely on rotational or gravitational forces to store energy, including flywheels and compressed air systems. These systems store kinetic energy and release it to generate electricity when needed.

Pumped Hydropower Storage

Pumped hydropower storage involves two water reservoirs at different elevations. Water released from the higher to the lower reservoir generates electricity, while power is used to pump water back up, recharging the system.