Energy Storage
Saving energy today to make tomorrow bright!
Renewable energy – one of the terms most synonymous with climate change – has the potential to power all of the world’s electricity needs. While the use of renewable energy has been increasing at a rapid pace, only 30% of the world’s electricity consumption actually comes from renewable energy. Intermittency of renewable energy sources, like wind and solar PV, is limiting further adoption. In simple terms, you can’t generate wind power when there’s no wind, and solar PV when there’s no sunlight. If the potential of renewables is so great, what can we do to overcome this?
Integrating energy storage systems with renewable energy solutions, such that excess energy that is generated can be stored for use when renewable energy is not being generated, will be critical to addressing the current intermittency challenge.
While strides have been made in the EV battery space, with lithium-ion and lead-acid batteries dominating the market, less progress has been made on technology for grid storage which is arguably a more pressing issue. To put this in perspective, 23% of energy-related CO2 emissions come from the transportation sector, while over 40% of energy-related CO2 emissions come from electricity generation. To achieve net zero targets, IEA expects nearly 600GW of battery storage capacity needs to be installed by 2030.
In order to scale grid storage to a meaningful level, it is imperative that we employ energy storage technologies that overcome the disadvantages of li-ion and lead-acid batteries. But this is easier said than done!
Energy storage can be expensive and alternatives to li-ion and lead-acid batteries still require further technology development before they can be commercialised. In addition, current infrastructure requires further development in order to facilitate grid integration, while clearer policies and regulatory frameworks need to be implemented to ensure smooth operation and integration between stakeholders. From a technology point of view, advancements need to be made to overcome the following:
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Energy losses during storage
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Trade-off between characteristics e.g. power density vs energy density
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Large physical footprint of battery technologies
But what are these alternative energy storage technologies that we’re talking about?
We’ve done some deep work on the merits and drawbacks of each of these storage technologies – what their best application might be, whether they can scale, whether the resources are abundant, etc. While we are keeping tabs on how each technology develops, as of now, there is no clear winner.
Some of these solutions are, however, receiving more and more attention:
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Alternative electrochemical battery technologies such as Manganese Zinc Oxide and Sodium Ion batteries
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Solid state batteries and lithium metal batteries
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3D Cell Architecture
So how do we judge which energy storage technology is ultimately going to prevail? The answer is that there probably won’t be just one winner and the solution will most likely vary based on location and application. However, there are some key areas that we should consider when assessing available technology and their potential to scale. These are:
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Energy density
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Power density
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Number of cycles
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Cost per kwh
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Materials availability
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Storage duration
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Safety features and thermal properties
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Physical footprint
For example, if we take some battery chemistries that are available today, we can identify some of the pros and cons for each technology by assessing them against the above parameters
Sodium Ion
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Low cost, abundantly available materials are used.
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Energy density is almost as high as li-ion batteries.
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Safe storage and transport given batteries can be discharged to 0V.
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Existing li-ion battery manufacturing lines can be used.
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However, progress is still required in terms of the technology, particularly in terms of the anode design.
Manganese Zinc Oxide
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Manganese and zinc are light, abundantly available and low cost and can be used in the cathode of batteries.
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These cathodes can improve the life of batteries.
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Manganese zinc oxide batteries are safer than li-ion batteries.
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They are also more environmentally friendly from a recycling perspective.
There are also some exciting new technologies which are not currently available commercially, but which have the potential to be game changers.
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Solid state batteries: While in traditional li-ion batteries, the electrolyte is a liquid, solid-state cells have a separator, generally ceramic or solid polymer, which also works as the electrolyte. In theory, solid-state batteries offer many improvements over existing batteries including:
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higher energy density due to the use of a pure metal anode instead of a graphite anode
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longer life
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greater safety and smaller size
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greater ability for fast charging given liquid electrolytes tend to suffer at high temperatures, while solid electrolytes achieve high-performance at high temperatures
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However, solid-state battery technology is still in its development phase and given that production has not commenced, the cost is very high. Some estimates state that solid state batteries will not be commercially available and deployed until 2030.
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3D cell architecture: The technology for 3D cell architecture has been developing for decades and while it has been theoretically proven, it has not been commercialised yet. Batteries that incorporate a 3D cell architecture:
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Have the ability to achieve high power density and energy density simultaneously
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Enable an increased energy density within a small footprint
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Enable better thermal management due to decreased resistance within cells
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Have fast charging capability with low impact on battery life due to better thermal management
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Additionally, the technology for 3D cell architecture is not chemistry dependent and can be modified to work for different battery chemistries.
So where does this leave us? It is clear that significant technology advancements are required to scale energy storage at a grid level. But there are other things we can do in the interim to make the transition smoother. This includes advancing current infrastructure to facilitate grid integration and implementing clear and transparent policies and regulatory frameworks to ensure smooth operation and integration between stakeholders. As sustainability venture investors, one of the most important things we can do, is to understand and support the building and development of new technologies in ways outside of just capital (although that too!), by promoting resources, building our own knowledge base, connecting partners to each other, providing introductions to corporates that can support such technologies.
Partner's Note: At Peak, we like to understand complexity. Energy is not just one of our key themes, but it's arguably the single most important theme for achieving global climate goals. According to us, one of the most important areas within energy is energy storage. Simply put, you can generate all the renewable energy you want, but if you can't store it for use later - what's the point? Sarah and the team have gone deep - so deep that she's thinking about pursuing her PhD in chemistry (joking) - to understand the intricacies within different battery chemistries, and what will scale. As of now, it's still early days for many of these innovations, but that's what venture investors do best. Stay tuned to see which bet we take in this space.