The evolution of energy storage batteries: from emergent technology to a mature market

In our pursuit of a sustainable future, energy storage has emerged as a crucial component of the global energy landscape. Indeed, as more and more homeowners look to transition towards clean, low-cost energy, the installation of energy storage batteries is spiking.

With this rise of the home storage battery has come rapid technological advancement.

Driven in part by consumer demand, in part by the needs of the climate crisis, and in part by surging energy poverty – manufacturers are pumping intensive R&D into battery storage tech.

In the past decade alone, the payoffs have been incredible. Battery storage has evolved from an emergent technology into an increasingly mature market. And, in the process, the technology has made extensive advancements in a remarkably short window. 

Here, we delve into the improvements revolutionising the energy storage industry.

Capacity: pushing the boundaries 

One of the most significant advancements in battery storage is the exponential increase in capacity over the past decade. Simply, home batteries can now store and discharge much larger amounts of energy over time.  

The early lead-acid batteries, which had limited capacity, paved the way for nickel-cadmium (Ni-Cd) batteries that offered a higher energy density. Then came Lithium Nickel Manganese Cobalt Oxide (NMC) batteries, which again boasted improvements on predecessors. 

However, it was the advent of the Lithium Iron Phosphate (LiFePO4) battery that truly sparked a revolution in capacity. With LiFePO4 batteries – and their prismatic cells –  also came the potential for substantial gains in power density, lifespan, performance, and safety.

We’ll use our own systems as a living example. In 2018 – only five short years ago – the most powerful GivEnergy residential battery had an individual capacity of 5.2kWh. Fast forward to 2023 and this capacity has more than doubled. Now, we offer a capacity of 13.5kWh from a single system.  

This kind of increase is representative of the accelerated pace with which the home battery is evolving to meet ever-bigger power needs.

Life span: prolonging battery lifetimes

As the demand for battery storage increases, so does the need for longer-lasting and durable batteries. The early generations of batteries had a more limited cycle life, degrading after a certain number of charge-discharge cycles. This limitation was a major hurdle for the widespread adoption of battery storage systems. 

However, with advancements in materials, manufacturing processes, and battery management systems, battery life span has significantly improved. Take LiFePO4 batteries. Storage batteries built using LiFePO4 technology have undergone extensive research to mitigate degradation issues and increase the number of charge-discharge cycles they can endure. 

We’ll use another real-world example to illustrate this point. For our earlier batteries, the GivEnergy performance warranty guaranteed that each battery pack would retain 70% use of its capacity for usage of 10MWh of energy throughput per 1kWh of usable capacity at 90% depth of discharge. (Equivalent to 5000 full cycles.)

The newer batteries in our range now allow unlimited cycles for 12 years and still be covered, at 100% depth of discharge. In terms of impact, this improved life span has not only made battery storage more economically viable, but has also reduced environmental footprints. (By minimising the need for replacements.) 

Again, such gains highlight the impressive – and fast-moving – journey of energy storage technology.


Depth of discharge: tapping into more energy

A phrase mentioned above was “depth of discharge”, or DoD. A critical metric for energy storage systems, DoD indicates the proportion of energy that can be extracted from a battery before recharging.  

For example, if a battery offers 80% DoD, then 80% of that battery is usable. Higher DoD values, then, translate to greater flexibility in energy management and higher overall system efficiency.

Historically, batteries had limited DoD to protect them from damage caused by deep discharging. However, modern battery technologies have significantly improved in this aspect. Less than a decade ago, 80% discharge was considered highly competitive. Today’s LiFePO4 batteries can now achieve a DoD of 100%.

So, in a short space of time, the leading battery storage manufacturers have succeeded in hyper-optimising the utilisation of stored energy – allowing customers to tap into more energy than ever before.

Round trip efficiency: maximising energy output

Some energy is always lost in the transfer process. Round trip efficiency, then, is a measure of how efficiently a battery can store and release energy. In simple terms, it represents how much energy is put into storage that is subsequently retrieved. (I.e., not wasted.) The higher the round-trip efficiency, the less energy is lost in the storage process. 

Older battery technologies suffered from lower round trip efficiency – with 80% being considered a good benchmark. This resulted in an average ~20% energy loss during the storage and retrieval process.

However, with advancements in chemistry and battery management systems, modern batteries now boast much higher round trip efficiency rates.

To use our own R&D as an example, we can now achieve round trip efficiency of 93%. Such solid efficiency makes battery storage an increasingly attractive option for both residential and commercial customers alike.

Installation ease: empowering consumers

Alongside technological advancements, installation ease has played a vital role in the growth of the energy storage market. As the industry matures, manufacturers are increasingly focusing on making energy storage systems more accessible and user-friendly.

In the early days, energy storage systems often required specialised expertise for installation and maintenance. However, as battery technologies advanced and standardisation efforts were made, installation processes have streamlined. Now, any qualified electrician can learn how to fit storage batteries within just a couple of hours. 

Plus, systems themselves have become easier to fit over time. Taking an example from GivEnergy, our latest All in One system – combining an integrated battery and inverter plus a backup gateway – comes with inbuilt isolator, CT clamp, metering, and switchgear. So, from an installation perspective, there’s very little to fit plus minimal wiring. 

Meanwhile, plug-and-play solutions, improved safety standards, and user-friendly interfaces have empowered installers and consumers alike to adopt energy storage systems with ease.

A bright future ahead

The evolution of energy storage batteries – from an emergent technology to a mature market – has been nothing short of extraordinary. The rapid advancements in capacity, life span, depth of discharge, round trip efficiency, and installation ease have paved the way for a sustainable energy future. 

At GivEnergy, we firmly believe that the journey is far from over. The energy storage sector will continue to witness groundbreaking innovations, with research and development ever pushing the boundaries of what is possible. 

Further reading