We have utility scale batteries with the solar arrays, in my area, which takes care of that issue
Unfortunately, I don't think BESS is the silver bullet some make it out to be. (I work closely with energy projects worldwide, and I landed late last night from a very large-scale project outside of the USA where the BESS has failed/again.)
To be clear, modern battery systems can provide extremely fast frequency response and reactive-power support, and newer systems employing grid-forming controls can emulate some of the behavior traditionally provided by synchronous generation. But that isn't identical to the inherent physical inertia, fault-current contribution and other characteristics provided by large rotating synchronous machines.
Grid-following and grid-forming BESS also need to be distinguished. Grid-forming systems are specifically designed to operate in weaker grids and can establish a voltage and frequency reference rather than simply follow one. Nevertheless, what a BESS can actually deliver remains constrained by its inverter rating and controls, current limits, available energy/headroom, state of charge and the characteristics of the surrounding power system.
The April 2025 Spanish/Portuguese blackout is an interesting example that I am very familiar with. Contrary to some of the early speculation, insufficient inertia was not identified as the cause. In fact, inertia immediately before the event was above recommended level. The final investigation instead identified a combination of oscillations, inadequate voltage/reactive-power control, rapid reductions and disconnections of generation, and cascading voltage increases.
What is relevant to this discussion is that Spain had an unusually low number of synchronous generating units connected that day, the lowest since the beginning of the year according to the Spanish government's investigation and the system ultimately had insufficient dynamic voltage-control capability.
That illustrates my concern rather well. Renewables and batteries clearly work. The problem is that when synchronous generation is displaced by inverter-based generation, we have to make sure we deliberately replace all of the system characteristics and ancillary services those rotating machines were providing; not merely their MW output.
That includes frequency support, voltage/reactive-power control, system strength, adequate fault-current contribution, disturbance ride-through and, where required, physical or synthetic inertial response. BESS can provide several of these functions and grid-forming BESS are becoming increasingly capable, but simply adding MWh of batteries does not automatically solve every one of those problems.
There is also another tradeoff that tends to get glossed over. Large lithium-ion BESS installations introduce a different risk profile, including thermal runaway, fire propagation and potentially deflagration. The technology, chemistry, detection and mitigation systems continue to improve rapidly, but the hazard has certainly not disappeared. There is a reason UL 9540A and NFPA 855 devote so much attention to thermal-runaway propagation, large-scale fire testing, separation distances and deflagration.
It's an issue I deal with closely in my work, where I have been involved with more than 200 catastrophic situations so far. Many modern utility-scale installations now use modular outdoor enclosures or containers, with engineered physical separation between units, rather than concentrating very large amounts of battery energy in a single enclosed space. The industry has become considerably safer, but the standards themselves recognize that the underlying hazard has not disappeared.
With every failure we learn more and improve. As one of my engineer friends likes to say, “Every one of these projects is, to some degree, a prototype. It's real-world R&D".
To bring it back to our audio world, I would say that the wattage number doesn't tell you everything about how the amplifier behaves into a difficult load.
