The “Polar Blast” of 2021 laid bare many flaws in the Texas energy supply network, and presented many opportunities for improvement. The changes that are needed – in infrastructure, policy, and operations, will be debated for months, if not years to come.
From early reports, it appears that nearly all sectors of the state’s energy supply network suffered damage or adverse operating conditions that reduced the ability to ensure continuous supply. Further, all generation sources (natural gas, fuel oil, nuclear, biomass, wind and solar) were impacted, with no single energy source being the culprit.
When examining the energy resources we use across the country, there are a number of commonalities. One important common feature is that all power sources have associated storage capability for the fuel they supply to power-producing equipment – generally enough to last days or even weeks. That is, all except one: intermittent renewable energy resources (typically wind and solar).
Coal plants have stockpiles on site. Natural gas generators have large underground storage fields plus “linepack,” i.e. the total volume of gas stored within the system. Fuel oil generators have nearby fuel tanks. Nuclear power has fuel rods that are periodically replaced. Most of our solar and wind plants, on the other hand, do not have this important long-duration storage capability included in their facilities. The result is that electricity networks are required to take the power they produce when it is generated.
We need to change this dynamic for the betterment of our grid and our nation’s energy security.
Short-duration (under four hours) energy storage from lithium-ion batteries is currently used on the power grid for some applications, such as keeping system voltages and frequencies within safe parameters, or reducing peak demand. Their durations can be from seconds to several hours.
Long-duration (more than four hours) storage technologies are now commercially available, economical to use, and able to handle massive amounts of energy. These systems can store excess intermittent energy from any source for four to 12+ hours with ease, and return it to the grid when needed. They can be cycled every day to minimize the cost of our energy supply and facilitate increased deployments of solar and wind. Indeed, long-duration battery storage is a primary mechanism for converting intermittent renewables to “firm” resources, which can be shifted in time for use when customers demand steady supplies.
They are also incredibly flexible and valuable during a power emergency.
These batteries do not require hazardous chemicals to operate, and the most environmentally friendly solutions are fully recyclable at the end of a long life of service to the grid. They can be “Made in America” without dependence on chemicals or technology from foreign countries that may be unfriendly to the U.S. They have the benefit of being deployable on a distributed basis to take full advantage of weak points in the network, or to provide resilience during emergencies. They work equally well with all generation sources.
As far as where to locate them, energy storage units can be included in new facilities but, importantly, they can also be located where recommended by grid operator ERCOT and Texas’s electric distribution companies (Oncor, Centerpoint, Entergy and others) for strategic benefits. Solutions that can fulfill this need include iron flow batteries, gravity-fed systems, pumped hydro and, in the longer term, stored hydrogen, among other options.
Long-duration energy storage systems, in conjunction with clean, renewable generation, can lead us to a better, more secure, sustainable energy future.
Michael Niggli, a Texas resident, worked for more than four decades in the energy industry, having served as President, CEO and Chairman of several major utility companies. He is currently Chairman of the Board of ESS, Inc., a manufacturer of energy storage systems.