What factors are preventing large scale deployment of long duration energy storage?

Given the current political climate, the continued deployment of renewables, energy storage and other low carbon energy solutions (like hydrogen) face significant headwinds. The latest issue of Chemical & Engineering News features an article that discusses these hurdles - specifically for long duration energy storage (LDES). The search for long-duration energy storage.

The punchline: Battery OEMs are ready to commercialize and deploy LDES technologies but utilities are unwilling to take the leap from Lithium Ion to LDES. Supporters say that there is no time to lose if we want to continue decarbonizing the grid.

Let's explore why.

Some relevant context:

• Lithium Ion batteries typically operate for less than 4 hours.
• Long duration technologies are primarily flow battery chemistries, along with emerging thermal and chemical technologies, that operate between 4 and 10 hours and as long as 24-72 hours.
• Most battery technologies have coupled power and energy. Imagine a car where the power of the engine (hP) and the size of the gas tank (gal) are directly related. One cannot independently choose the size of the engine and fuel tank.
• Energy storage facilities have useful lives measured in decades. It’s tough to build a business case for a use case that doesn't yet exist for a facility with a fixed configuration. A utility wants flexibility so that expensive, long life assets do not become stranded.
• Utilities are asked to make risky bets that are not yet rewarded. The holy grail in energy storage is an energy storage solution with exceptionally high volumetric energy density and perfectly decoupled power and energy. What if a utility could add more energy capacity as the market develops?

The challenge to solve: OEMs need real world operating experience to convince utilities to deploy but utilities won't deploy until the technology is developed and the market exists.

Who are the leading LDES contenders and what is their kryptonite? The leading LDES flow battery chemistries are Metal Redox (Vanadium, Iron, Chromium), Metal-Air and polysulfide based. All suffer from low volumetric energy density, or how much energy is stored per unit volume (ex. Btu/gal or kWh/L).

A frame of reference: 1 GWh of energy can power 100,000 average American homes for 8 hours*. This energy (1 GWh) is stored in either 83 cubic meters of gasoline or 20 Olympic swimming pools of iron flow electrolyte - 600x the volume!

A misconception: The industry focuses on efficiency. The appropriate benchmark metric is cost to serve or Levelized Cost of Storage (LCOS) for a specific use case. A high efficiency battery does not matter if the battery not cost effective.

The consequence: We will need a much larger volume (and footprint) to store a unit of energy in a decarbonized energy system. The volume and footprint will only increase further as we choose to store energy for a longer duration. Increasingly large equipment is capital intensive, so full life cycle costs must reduce disproportionately. These assets require major capital investment with long asset lives in a market that does not yet exist.

So how do we work together to bridge the gap? The first answer is always “the government should subsize it”. While I believe that the government should play a role in helping new technologies bridge the valley of death, in this case, we can all work together. It takes a village to raise a child (and to develop a new market!).

1. We must reimagine how energy storage is used to support a decarbonized grid. We must develop novel use cases and strategies to support initial deployments. Many are actively identifying creative solutions. In the early days of Lithium Ion, initial deployments earned their keep by providing ancillary services, not through peak shifting. Can we apply similar thinking on an inter-day or inter-week time scale?
2. We must jointly to develop appropriate revenue models to compensate LDES assets for the services they provide. Can ISOs pilot novel structures with initial small scale deployments? Can utilities offer a pilot program for 24/7 green energy for customers. Would early adopter consumers who are willing to pay, participate in these pilot programs?
3. End users and OEMs must partner to de-risk and commercialize current technologies in real world situations now so they’ll be ready to commit to bigger projects in the next decade when the market develop. Hard tech isn't developed overnight. Real world operating data is essential.
4. R&D must continue: OEMs and researchers must continue improving energy density and developing chemistries with decoupled power and energy.?Society's demand for energy is insatiable. We must develop novel solutions to meet the challenge.

In many jurisdictions, renewables are the lowest cost (marginal and total) generation source, even without supporting policy or tax incentives. As the penetration of renewables increases, the grid will transform at an increasing rate, requiring energy storage solutions to keep it balanced. These solutions take many years to validate, so let's work together to develop them now so they are ready when we need them.

Where can you learn more about the challenge and solutions?

• The Long Duration Energy Storage Council (LDES Council) , an industry group, and most major consultancies and market research/analytics firms (like McKinsey, BCG, Deloitte, Wood Mackenzie, and BNEF) publish relevant white papers and case studies.
• National Laboratories like National Renewable Energy Laboratory and Pacific Northwest National Laboratory have research programs underway that focus on future energy systems.
• Follow Omar José Guerra Fernández at NREL. He does great research and modelling of deeply decarbonized energy systems.
• Ascend Analytics (and similar analytics firms) publish case studies that explore creative solutions for deployment and long term valuation of future energy systems (example Assessing Energy Resource Value: Opportunity Cost Forecasting Framework Outperforms Traditional Cost Models). I like their work because they rigorously apply sound economic principles to their modelling.

?* Average consumption of 30kWh/d per home