With decarbonization moving forward, it has become clear that energy storage will be one of the key enablers. This is for a variety of reasons. To phase out fossil fuels, there will be more renewable energy resources integrated into the grid. However, the absence of flexibility provided by gas-fired plants will not be addressed by wind or solar given their variability from moment to moment. In addition, the influx of new energy sources places a strain on the existing infrastructure, already exacerbated by booming electrification. Energy storage serves as the bridge, providing the flexibility needed to not only fill in the gaps, bringing the necessary balance between supply and demand, but to also shift surplus generation to more optimal times.
Energy storage is crucial for the energy transition. The long-term targets are clear, but the pathway can be considered indeterminate. The near-term focus has shifted to long-duration energy storage (LDES). To note, the definition of LDES has evolved over time. Initially it was any storage for longer than 2 hours; perhaps this was a limitation of its time where 2 hours was significant and potentially harder to achieve. This imprecise term has covered systems rated for 6+ hours of full capacity discharge .
LDES has significant potential to make an immediate impact on a grid-level. When located in front of the meter, this energy storage directly feeds into the power grid to be transmitted to end users. From this location, a system can address many of the short-term needs. For instance, the general increase in electrification is intensifying the load on the grid. The direct way to solve this would be to update the infrastructure; this would involve building out the transmission lines, fortifying them for greater capacity . Most of the legacy equipment was designed and built to deliver electricity from centralized resources, such as thermal power generation; becoming decentralized and more interconnected will allow for more distributed generation resources . This kind of construction need is easy to identify but the actual implementation is complicated. There are multiple stakeholders at play from the government level to the utility to the grid operators to municipalities and beyond. Coordination of these stakeholders and acquiring the necessary investment takes considerable time. An LDES can allow this kind of network-strengthening investment to be deferred, optimizing how finances are allocated and reducing risk of a long-lasting project not being used when finally ready . The infrastructure changes then can be approached systematically without a deficit in the grid.
With the integration of intermittency from renewable generation, the capacity of the grid can become unstable. Grid operators must monitor which power sources are available to meet the demand. The dispatchability of LDES creates a firm capacity, facilitating better tuning of grid frequency and ensuring a consistent supply of electricity, resulting in grid stability . This allows a balance in the use and transition between resources. In addition, this provides security in supply since energy storage can fill the gap when another system is unavailable. An obstacle to embracing the full potential of storage has been the need for supportive policy and market frameworks . The industry as a whole needs to standardize the approach to energy storage at least to some level. At least there has been global consensus on the need and efforts are being made to create a framework for regulations in the future .
So is LDES the solution moving forward? The answer is yes, but it is one of many. It is Nilar’s belief that there will be a multitude of different solutions working in synergy to truly gain the decarbonization desired; collaboration and concurrent progress are the key. It appears the world is coming together to invest in many different pathways forward. And according to recent assessments by the International Energy Agency (IEA) and Intergovernmental Panel on Climate Change (IPCC) for the United Nations, there is still time to have an impact on climate change through decarbonization as long as we act swiftly, now