What Is A Battery Energy Storage System?

Battery energy storage systems capture and store energy produced from renewable sources or harvested from the National Grid, ready to be used when needed. The ability to safely store large amounts of power is a crucial part of the UK-wide Smart Grid and is fundamental to our widespread adoption of renewable energy sources. But what is a battery energy storage system? In this article, we explain what battery storage solutions are, how they work, and why they’re the future.

Energy Storage Explained

Energy storage systems provide a way for energy producers or those who want to capture energy a means to store it away for use at another time. The power can come from anywhere: it can be taken directly from the grid or from renewable sources, like solar, wind or water. 

Battery energy storage systems (BESS), use several batteries, linked together with control systems to safely store power. The benefits and potential for battery energy storage are immense. They enable renewable energy producers to capture all of the electricity produced, storing it away to be released back to the grid when it will earn the best price. 

BESSs are also popular with commercial companies who can use the stored energy to power uninterruptible power supplies (UPS) if their buildings and critical information systems loose power. It’s a cost-effective and secure way to provide power to systems that matter.

Why Batteries?

Historically, mechanical energy storage systems have been bulky, expensive and inefficient. Recent leaps in battery technology, accelerated by the adoption of electric vehicles and supported by a significant investment from car manufacturers, have seen battery prices slashed by 87% in the last decade. These changes mean that today’s batteries are a safe and stable way to store energy.

The majority (some 90%) of the world’s battery storage systems use lithium-ion (Li-on) batteries. Lithium-ion batteries are simple to build, safe and stable – making them perfect for storing energy. Individual lithium-ion batteries are constructed from cells, modules, and packs. Battery packs are built by linking together modules in series or parallel. They’re then housed in a heavy-duty plastic case. 

Lithium-ion batteries have a high energy density, meaning they pack a significant amount of power for their size. The potential for battery storage is immense. They can work at utility-scale, as proven by the Tesla, Greensmith Energy and AES Energy Storage facility in California that can store an incredible 70 megawatts. 

One of the key benefits of a battery energy storage solution is its ability to be scaled. By adding more batteries to the system, you can increase its total storage capacity. This scalability enables producers to safely grow the size of their storage solution as they themselves grow. It’s a cost-effective solution that supports business expansion.

How Does Battery Energy Storage Work?

Wherever the power comes from (power plants supplying the electricity grid or from renewable sources) the battery storage system will draw power and charge the batteries until it reaches the desired level. Within every energy storage solution, a smart controller that manages and maintains the system, ensuring the safe charge and discharge of all batteries. It can monitor the health of each battery pack and alert the operator if there are any problems.

Each battery energy storage system built by Carter Sullivan is safely integrated into the National Grid. They’re fitted with a smart inverter that knows when to supply energy to the grid to maximise your return. Every system includes crucial safety protection like an import/export controller and G99 convertor demanded by regulators. The system is built on-sit and configured to work with minimal maintenance.

On-site battery energy storage systems work in a similar way. Power can be stored in the battery packs during off-peak periods when tariffs are lower. They can then be switched on during high-tariff (red price) periods. Over time, this can save significant amounts for organisations. During a power outage, the system can be used to provide emergency power, acting as an uninterruptible power supply, until engineers can reconnect the power or systems can be safely shut down.

How Safe Is Battery Energy Storage?

Battery energy storage systems are safe and effective if they are installed, configured and maintained by trained professionals. It’s particularly important when storage systems are integrated with the National Grid.

Specific issues battery storage systems may be susceptible to include:

• Thermal Runaway – when batteries enter into a damaging cycle where heat creates more heat, leading to the rupture of cells, the build-up of gas and fire. 
• Battery Management System Failure – If the control system of your battery fails, it can lead to over-charging, over-heating and eventual system failure.
• Surge Damage – Lithium-ion batteries are highly-sensitive and can react negatively to electrical surges and mechanical damage.

While it’s impossible to protect against every eventuality, at Carter Sullivan, we design, install and manage every battery installation with safety in mind. We’re experts at safely integrating battery storage systems within your organisation and infrastructure.

What Is The Future For Battery Energy Storage?

Battery energy storage systems will play a fundamental role in the future of power in the UK and across the world. As we shift toward the renewable generation of power, BESSs can provide stability to the grid, tackling the challenge of frequency regulation. Essentially, this means that we can all draw the power we need when we need it.

As a nation, we will need to incorporate a greater number of smaller, renewable energy providers to achieve our emissions-reduction targets. Battery energy storage systems can provide a cost-effective way for these producers to sell energy to the grid, maximising their profits while protecting the planet for all of us.

The ability to call upon these ancillary services is critical to the development of the UK-wide Smart-Grid, a flexible network that can increase or decrease power supply to the National Grid depending on demand. It’s all managed by incredible new connected technology like Smart Meters. You can read more about the Smart Energy plans for the UK here.

As the cost of energy continues to increase, larger organisations are investigating cost-effective and environmentally friendly solutions like battery energy storage. Over time, the costs of installation can be offset against significant savings on energy prices. They also provide a demonstration of solid green credentials while providing energy resilience that can be called upon any time it’s needed.

Click here to learn more about how Carter Sullivan can integrate Energy Storage into your business.