The next point of view is written by Eric Svahn, Director of SGA
Cities are where the highest demand for electricity occurs, as dense populations, commercial activity and critical infrastructure feed heavily into the grid, often simultaneously. This strain is intensifying as electrification accelerates in buildings and transport, and as extreme weather events cause sharp spikes in demand for heating and cooling.
During these times of peak load, network systems are pushed to the limit, exposing vulnerabilities in throughput and response times. In response, utilities are increasingly turning to utility-scale battery energy storage (BESS) systems that feed directly into the utility grid, placing them closer to urban areas.
For these facilities, proximity is essential. As urban demand continues to grow, locating utility-scale grid-connected storage closer to dense urban areas can reduce transmission losses, provide faster response during peak events, and strengthen overall grid reliability. However, the open land needed for traditional field facilities is simply not available in metropolitan areas, forcing developers to rethink how BESSs are built.
Why traditional battery storage doesn’t work in cities
BESSs have typically been designed as horizontal containerized installations with rows of units spread across large open plots of land in suburban or green settings, typically three times the land of vertical equivalents. These layouts rely on ample space with limited surrounding development, conditions that are increasingly rare in dense urban environments.
In cities, available land is scarce and expensive, zoning regulations are more complex, and sites must compete with higher-value uses such as housing or commercial development. Also, battery storage works best when it’s near an electrical substation, because that’s where the power is connected to the grid. However, in dense metropolitan areas, land near substations is often scarce, built on, or zoned for other uses. As a result, the traditional model of battery storage does not translate to the realities of cities, making it clear that the only viable option is to build.
Building vertically is a new approach, and many municipalities haven’t even come across it or been introduced to it. Reconfiguring the traditional approach, vertical battery storage facilities are multi-story, enclosed facilities specially designed for the constraints of urban environments. By stacking batteries, floor usage is reduced, making a smaller batch more feasible.
Stacked System Engineering
The vertical BESS represents a fundamental change in both infrastructure planning and building design. These facilities are highly organized systems where the placement of each component affects performance, safety and efficiency. In a stacked configuration, batteries generate DC (direct current) power that travels through wiring to banks of inverters, which convert it to AC (alternating current) and feed transformers that step up the voltage to match grid requirements. Optimizing these pathways is critical to reliability. Short logic circuits reduce power loss and ensure that the system can respond quickly to peak load events.
Stacking batteries also presents structural and spatial challenges. Racks weighing tens of thousands of pounds must be supported by reinforced slabs and structural systems, with floor-to-floor heights designed to accommodate wiring, piping and ventilation. Thermal management, explosion prevention and separation between battery rooms and control spaces are carefully designed to keep the installation safe and resilient. In essence, the building functions as a circuit board where every element, from the battery rack to the transformer and wiring, is placed for maximum efficiency and reliability.
Benefits of sustainability
BESS plays a critical role in advancing the sustainability of the electricity grid. By storing excess energy from renewable sources such as solar and wind when generation is high and releasing it when demand increases, BESS helps reduce reliance on fossil fuel power plants and smooths the variability of renewables. Storage also shifts the use of electricity to times when low-carbon energy is available, avoiding the need to use backup fossil generators and reducing overall CO₂ and pollutant emissions.
By storing energy when it is cheap or clean and discharging it when it is expensive or dirty, BESS helps to optimize the energy usage pattern, reduce costs and reduce overall emissions. Its fast response also enables ancillary services such as frequency regulation and voltage support that improve grid reliability without burning fuel.
As new energy codes are revised to meet carbon reduction targets, building systems are increasingly required to be fully electrified. BESS plays a key role in enabling this transition. By providing grid flexibility and support, BESS helps ensure that electrification targets can be met with clean, low-carbon energy rather than fossil fuel backups, making compliance with sustainability codes practical and effective.
Navigating the municipal and regulatory unknowns
Incorporating BESS into a closed building is a new frontier. Few have been built, and they proposed new questions in the matter of fire protection by local municipalities. Municipalities in denser communities are skeptical about the benefits and dangers these BESS systems bring or may create. Zoning codes, building classifications, and permitting processes were typically written for conventional industrial buildings or horizontal containerized systems, leaving gaps when projects proposed multi-story enclosed battery facilities.
Successfully navigating these regulatory unknowns requires extensive coordination and education. Architects, engineers and code consultants play a critical role in guiding city officials, fire departments and utility agents through the design, safety and operational principles of stacked BESS.
For example, fighting a lithium-ion battery fire, whether in an electric vehicle (EV) or BESS building, is very different from fighting a typical gasoline or electric fire. The main concern is thermal runaway: a chain reaction inside battery cells that can cause re-ignition hours later. Current EV firefighting strategies involve pulling the car into an isolated area and dousing it with water to keep it cool and contained. Car batteries are well protected inside the vehicle, making it difficult to extinguish. In a building, batteries are very heavy and cannot be moved. Therefore, fire protection systems are designed as dangerous, with a greater flow of water. If a BESS building catches fire, firefighters are unlikely to enter the battery room. Instead, they would put out the fire from outside space. The high volume of water, from the high hazard sprinkler system and additional hose streams, would require effective drainage and removal from the room.
Beyond on-site fire response considerations, battery systems must undergo compartmental testing prior to deployment. The exact battery configuration is assembled and then stress tested, typically by overcharging a battery and starting a fire, to assess system performance under failure conditions. A BESS consists of smaller, brick-sized batteries arranged in shelves and stacked in racks, making the containment strategy central to the overall security of the system. Stress test results provide data on how effectively thermal events are contained, measuring whether a fire spreads from one attempt and from frame to frame.
Vertical BESS projects are also accelerating the shift from traditional design-bid-build to integrated EPC (engineering-procurement-build) and construction management delivery models, where design, procurement and construction occur in parallel. This is to accommodate the rapidly evolving technology and high complexity of urban battery systems, allowing the project to adapt to site-specific conditions, regulatory requirements and operational constraints without delay.
A New Frontier
Unlike traditional industrial buildings, the vertical BESS must accommodate highly technical systems while responding to site constraints, zoning regulations, and community concerns. By treating energy storage as a building and infrastructure system, architects help ensure that vertical BESS projects are operationally efficient, integrated and contextually appropriate for the urban environment.
Transforming the way cities manage and deliver energy, these facilities enable utilities to manipulate energy flows more efficiently while offering customers lower costs, reliability and cleaner, smarter energy management. As urban populations and electrification continue to grow, the need to store energy close to demand centers will only increase, making vertical installations an attractive and practical solution for cities moving forward.
Eric Svahn, director of SGA, it concentrates on the commercial and life sciences markets. Although he is involved in all phases of the project, his specialty is construction documentation and construction administration.
