BATTERY Energy Storage Systems (BESS) have emerged as a versatile, efficient and cost-effective solution to the challenges of integrating variable renewable energy sources and maintaining grid reliability, making them an essential component in pursuing sustainable energy goals.

In recent years, the energy landscape has undergone a transformative shift, driven by the imperative to achieve climate goals and reduce carbon footprint. The growth and expansion of renewable generation globally have been among the energy sector’s greatest successes over the last decade.

However, this brings the challenge of maintaining efficient and effective power grids by properly integrating variable renewable energy sources, such as solar and wind. As the penetration of renewable energy increases, maintaining grid reliability becomes ever more challenging and costly.

Driven by technological advancements, cost-effectiveness and versatile applications, Battery Energy Storage Systems (BESS) are rapidly gaining ground over other common energy storage solutions, such as Thermal Energy Storage (TES), as a critical component in ensuring a stable and reliable energy supply.

UNDERSTANDING BESS AND TES
Before diving into the reasons behind the growing preference for BESS, it is essential to understand what these systems entail. TES systems store thermal energy for later use, primarily for heating or cooling purposes. They typically involve mediums like water, molten salts, or phase-change materials to store excess thermal energy during off-peak hours and release it during peak demand. TES has been widely used in applications such as District Heating, industrial processes and even power generation.

BESS stores electrical energy in the form of chemical energy within batteries. These systems capture excess energy generated during periods of low demand and release it when the demand is high or when renewable sources like solar and wind are not producing. Lithium-ion batteries are the most common type used in BESS due to their high energy density, efficiency and long cycle life. BESS are employed in a variety of applications, from grid stabilisation and renewable energy integration to backup power for residential and commercial use¹. One example is in Maryland, in the United States, where Hitachi Energy leveraged a BESS to solve Baltimore Gas and Electric’s challenge of meeting peaking power demand, as residents switched on their heating in the winter months. The additional power provided by the new BESS, which became operational in November 2023, not only alleviates strain on the grid and improves the reliability of the local power supply throughout the year, it also paves the way for incorporating more renewable energy into the future energy mix.

THE RISE OF BESS

One of the primary drivers behind the increasing adoption of BESS is the rapid advancement in battery technology. Over the past decade, significant improvements have been made in battery chemistry, particularly with lithium-ion batteries. These advancements have led to higher energy densities, longer lifespans and improved efficiency, making BESS a more attractive option for energy storage.

Moreover, the development of advanced power management systems has enhanced the capabilities of BESS. These systems use real-time data to optimise energy storage and release, further increasing the efficiency and reliability of BESS.

Beyond technological advancements, declining costs of batteries have tipped the scales
in favour of BESS. While TES has traditionally been seen as a cost- effective solution for thermal energy storage, the cost of lithium-ion batteries, in particular, has dropped significantly, making BESS more affordable for a wide range of applications².

Additionally, BESS can provide greater economic benefits through various additional revenue streams that make BESS a more financially attractive option for both utilities and consumers. For instance, battery storage systems can participate in demand response programmes, where they provide power during peak demand periods and receive compensation for it. They can also optimise energy usage by purchasing electricity during off-peak hours, when prices are lower, and supplying it back to the grid during peak hours to help balance supply and demand³.

A SWISS ARMY KNIFE FOR ENERGY TRANSITION
Much like a Swiss Army Knife, another key advantage of BESS is its versatility and flexibility. Unlike TES, which is primarily used for heating and cooling, BESS can store and release electrical energy for a wide range of applications. This multifunctionality makes BESS suitable for various sectors, from residential and commercial buildings to large-scale industrial operations and utility grids.

BESS also offers quick response times and high efficiency in energy storage and release. BESS systems can seamlessly integrate with renewable energy sources, providing reliable backup during periods when solar or wind energy is not available.

Continuing with the Swiss Army knife metaphor, BESS is also very adaptable to different energy sources. It can balance intermittent renewable energy sources and stabilise the grid. This capability is crucial as the world moves towards a more sustainable energy future, ensuring that power is available whenever and wherever it is needed⁴.

ENVIRONMENTAL IMPACT

While both TES and BESS contribute to reducing greenhouse gas emissions by optimising energy use and integrating renewable sources, BESS have a more direct impact on reducing carbon footprint. By storing excess renewable energy and releasing it during peak demand, BESS helps to displace fossil fuel-based power generation, thereby cutting down on emissions. Advancements in battery recycling technologies are addressing environmental concerns related to battery disposal, making BESS a more sustainable option³.

REGULATORY SUPPORT AND MARKET TRENDS

Government policies and regulatory frameworks also play a significant role in the adoption of energy storage technologies. Many countries are implementing regulations and incentives to promote the use of BESS as part of their broader renewable energy and grid modernisation strategies. These policies are accelerating the deployment of battery storage systems and encouraging investments in research and development³.

Market trends further indicate a growing demand for BESS. The global market for battery storage is expected to witness substantial growth in the coming years, driven by the increasing penetration of renewable energy sources and the need for grid stability. As economies of scale are achieved and technology continues to advance, BESS is poised to become even more cost- competitive and efficient².

The recent shift towards BESS over TES reflects the changing priorities and goals of the energy sector. Electricity will be the backbone of the entire energy system, and as the world continues to move towards a sustainable energy future, BESS is set to play a pivotal role in ensuring reliable, efficient and environmentally friendly energy storage. The future of energy storage is undoubtedly bright, with BESS leading the way in enabling a sustainable, flexible and secure power grid.

The writer is Senior Vice President and HUB Manager, Middle East & Africa for the Grid Automation (GA) Business, Hitachi Energy. He may be contacted at nader.abdellatif@hitachienergy.com