Lithium-based battery technology for utility-scale battery energy storage system (BESS) installations is advancing rapidly. Manufacturers are continually modifying designs to optimize the configurations of battery modules, bidirectional inverters, thermal management systems, AC main breakers and controls so units can be shipped as ready-to-install units. These advances are changing the way that megascale battery energy storage facilities are designed and built.
These changes are making it even more important to engage in detailed site planning and to efficiently execute a wide range of preconstruction tasks with early input from construction.
An Installation Game
Though much of the battery equipment is becoming commoditized with standardized dimensions and other specifications, preconstruction planning to optimize transport and efficient installation on the site is more important than ever. Developers are recognizing that remaining competitive means controlling costs through efficient installation. That makes it imperative for the construction team to develop a site plan that optimizes constructability.
An increasing number of sites today are in urban areas, rather than in rural locations. This means tight restrictions on available space for equipment and materials laydown. This requires careful planning of logistics for delivery of materials and equipment. But even in rural areas with more open area, geotechnical and civil engineering will be important to determine whether pile foundations will be needed and whether there are any other subsurface conditions that could impact the facility.
Focus on The Four M’s
Preconstruction that is integrated with the engineer-procure-construct (EPC) project delivery model can provide a number of benefits in managing the four M’s: manpower, materials, machinery and methods.
With shortages of craft and trades being a well-documented trend throughout all sectors of the construction industry, a contractor that can provide custom fabrication can minimize the number of people actually needed on-site at any given time. Though industry is moving away from custom-designed enclosures, unique elements of most sites often make custom solutions a necessity for racks and other elements.
Self-perform capability can provide options for prefabrication of certain components, all while optimizing scheduling for crews with needed specialties for installation. Crews can arrive on-site and efficiently complete tasks such as connecting DC systems to inverters and then running power cables to the substation that connects with the grid. Once these tasks are complete, they are off to the next job, minimizing site congestion by the time the next crew arrives.
Supply chain difficulties are a common factor throughout the industry, making it rare that one vendor can deliver everything specified on a single purchase order at the same time.
This reality is making supply chain management a highly complex proposition that requires careful management and planning so that all materials are scheduled for delivery in the correct sequence. From batteries and transformers to inverters and bulk cable, all items must be scheduled so they arrive at the right location at the right time. With larger suppliers like ABB and GE facing the same realities as smaller vendors, value-added planning of supply chain logistics sometimes may require finding equivalent suppliers for certain components and integrating all of them once delivered on-site.
Modules and other equipment coming to the site from manufacturers are frequently arriving as loads that are at the maximum weight limits for surface roads in the area. Unloading these heavy materials today requires much bigger cranes with rigging that allows greater lifting capacities. Planning these lifts becomes even more important as cranes must be positioned directly beneath the weight centers of the load in order to perform a safe lift.
For urban sites with multilevel battery module installations, constrained footprints are often the case. This places an even greater premium on constructability planning as multiple cranes, forklifts and other types of materials-handling equipment often are required. Finding ways that support stacking of batteries in either open or enclosed configurations requires value engineering and constructability design that accounts for fire codes and other safety factors.
As the industry evolves, heritage battery technology designed primarily for electric vehicle applications is still on the market. As BESS facilities began being built, earlier designs favored placing them inside custom-fabricated structures that were erected before batteries were placed inside.
As fire codes have evolved to address thermal risks of these facilities, options to integrate battery modules into custom enclosures were developed. Today, these structures must meet all regulations ranging from seismic stresses on structural integrity to fire suppression for vertical structures. Construction methods must account for a significant amount of integration that still must be done on-site, even with more modules coming from manufacturers as ready-to-install units. From fire protection systems to piping, all components must be integrated into a common control system.
Mitigate Risks Through Better Constructability
Increasingly, early planning must go beyond initial construction and keep operations and maintenance and future augmentation in mind.
The energy storage market is on the upswing with many developers ready to deploy investment capital, even without full awareness of what is required for capital construction. For these players, the most valuable partner will be a one-stop shop that can deliver full EPC capabilities. From permitting to engineering, technology selection, procurement and construction, a project that is fully integrated with all disciplines reduces the likelihood of surprises, and that is always the goal.
As more battery energy storage facilities are developed, building these facilities vertically is an increasingly viable option, though it can create challenges for airflow, thermal management and maintenance.