While there is no single solution to the climate crisis, energy storage offers a significant opportunity to accelerate the transition to a low-carbon energy system and make a major global impact.
In the last century, our relationship with energy (that is, the ‘ability to do work’) has only grown. From the explosion of energy use in the form of steam engines during the industrial revolution to today, energy has made our lives easier, more convenient, and helped economies evolve. But as we look to combat climate change and move towards a low-carbon future, we need to find ways to lose the chains of fossil fuelled based energy and transition to a more efficient and sustainable system.
For society to achieve rapid decarbonisation, energy storage will play a critical role.
Energy storage and the low carbon economy
Fossil fuels are the largest contributor to global warming, accounting for almost 37 billion tonnes of carbon emissions in 2021 alone. The vast majority of these come from the energy sector, which also presents a considerable opportunity to decarbonise towards net zero.
Energy storage has become one of the most significant technologies for helping to decarbonise our power systems, as well as enabling a wide range of new technologies. In fact, research from Imperial College found that the UK will need at least 30GW of energy storage if it hopes to reach net zero by 2050.
Energy storage on the road to net zero
To begin with, storing energy helps replace polluting fossil fuels in balancing the intermittency of renewable energy sources like solar and wind. Whilst renewables are a large part of the solution, they are only effective when the sun shines or the wind blows. But, energy storage has the capability to address the problem by storing excess energy during production peaks and releasing it during production dips.
As Craig Lawrence from energy transition investor, Energy Transition Ventures puts it, “energy storage is the fundamental building block of a modernised grid. It’s able to be more flexible and efficient than a grid without energy storage, where supply and demand have to be perfectly balanced at all times.”
Second, energy storage enables the electrification of economies. This means replacing polluting processes, such as internal combustion engines, with electric motors or gas-powered heating systems with electrified heat pumps. These technologies are far more efficient and directly produce zero emissions during use.
Types of energy storage
Almost everyone’s daily interaction with energy storage comes in the form of batteries, those found in portable devices such as phones, computers, and cars, but these aren’t alone in the energy storage mix:
- Pumped hydro: Dominating the global energy storage landscape, accounting for over 94% of installed capacity, pumped storage hydropower involves using two reservoirs at different elevations to store energy. During low-demand periods, water is pumped up, when demand is high, the stored water is released from the upper reservoir, powering turbines to generate electricity.
- Flywheels: Using a rotating high-strength and high-weight material, flywheels store energy as rotational energy. Often built in a vacuum to reduce drag, flywheels can be brought up to speed using excess energy, or similar to pumped hydro, cheaper energy at times when demand is low.
- Batteries: The most well-known type of energy storage and often used synonymously with other energy storage methods, batteries store energy in the form of chemical energy. When the battery is connected to a circuit, the chemical reaction between the electrodes and the electrolyte is reversed, and the stored energy is released in the form of electrical energy.
The challenges with energy storage
Technologies, such as hydro and flywheels, have very specific use cases. Hydropower, for example, can produce a considerable output, but is restricted by local geography. Flywheels have a limited energy storage time of around 15 minutes and are only suitable for quick, timely applications.
Batteries, on the other hand, have seen a rapid adoption since they are extremely versatile and have plenty of applications. But, they do have downsides, they are still relatively expensive and lack the infrastructure for mass deployment at scale.
Virginia Klausmeier, president and CEO of clean tech start up Sylvatex explains, “the shift to an electrified world will require greatly increased renewable energy production, energy storage, and mineral production. As an example, California plans to add 85 GW of production by 2035, more than doubling their current production.”
“Battery materials are infinitely recyclable” she continues. “[But] there will not be enough recycled materials to be used at scale for at least another decade, due to a massive supply demand gap”.
Another challenge with battery technology is cost. As Craig puts it, “the challenge has always been cost. Historically, with the exception of pumped-hydro storage, which is limited in geography, other energy storage technologies have been too expensive.”
Virginia shares a similar viewpoint, explaining, “today’s [battery] solutions use metal sulfates to produce Cathode Active Materials (CAM), which are the major cost and carbon component in batteries. These materials are highly inefficient, leaving roughly 60% of their mass behind in the form of sodium sulfate waste, while utilising billions of gallons of water annually in the processing.”
But these challenges are being addressed. Through innovative processes from companies like Sylvatex, the price of batteries has fallen by 97% since 1991. To put that in perspective, a Tesla Model 3 battery (50 kWh) would have cost almost £29,000 in 2013, but it would cost just £6,000 today.
The future of energy storage
Hydro and flywheels have their applications, but batteries are poised to dominate the energy storage market in the coming years. A recent report by McKinsey projects that the global battery market will grow fourfold between 2021 and 2030, reaching a value of over $400 billion (£315bn).
There are several reasons for this growth. First, batteries are becoming more affordable and efficient. Second, the demand for renewable energy is increasing, and batteries are essential for storing and delivering this intermittent power. Third, governments around the globe are stepping up support for battery research and development, as they strive to lessen their reliance on fossil fuels.
The UK government is a prime example, and in 2021, it pledged £211 million in new funding for battery research and innovation. This investment is part of the UK’s plan to reach net zero emissions by 2050. The US government’s Inflation Reduction Act from 2022 along with the EU’s Net Zero Industry Act proposal are other examples of the heavy investment being directed towards clean technologies, including batteries.
Alongside the ever popular lithium-ion battery, there are several new technologies being researched which show promise:
- Solid-state batteries are considered to be the next generation of battery technology. They use a solid electrolyte instead of the liquid electrolyte used in traditional lithium-ion batteries. This makes them safer, more durable, and have a higher energy density.
- Graphene batteries are made with graphene, a material that is stronger and more conductive than carbon. This makes them potentially faster charging and longer lasting than traditional lithium-ion batteries.
- Molten metal batteries are batteries that use liquid metal electrodes and a molten salt electrolyte.
The future of battery storage is bright. With continued investment and innovation, batteries will play a vital role in the transition to a clean energy future. They will help to stabilise the grid, provide backup power during outages, and store energy from renewable sources. As a result, batteries will make our energy system more reliable, affordable, and sustainable.