Key Challenges in Expanding Hawaii’s EV Charging Infrastructure 

Hawaii is at the forefront of clean energy adoption, with a statewide goal of reaching 100% renewable energy by 2045. A key part of this vision includes expanding electric vehicle (EV) charging infrastructure to support the growing number of EVs on the road.

While progress is being made, developing a reliable and accessible EV charging network in Hawaii comes with unique challenges. Factors such as increased electrical demand, limited space, high installation costs, and infrastructure integration can add complexity to both new and existing projects. Understanding these factors—along with the specific requirements of EV charging systems—is essential for making informed decisions and contributing to Hawaii’s clean energy future.

1. Building Electrical Infrastructure

Many stakeholders are not fully aware of the scale of electrical upgrades involved in EV charging installations. While adding chargers may appear straightforward, the process is often far more complex—particularly at larger properties where demand can increase significantly.

EV Charging Systems without Load Management

The 2020 National Electrical Code (NEC) requires that electric vehicle charging loads not equipped with a load management system must be considered continuous loads, meaning that all circuits, overcurrent protection, and distribution equipment associated with EV charger(s) are required to be sized at 125% of the EV charging load being served.

Examples:

• A 40-amp, 208-volt, single-phase Level 2 charger, when calculated at 125 percent, is required to be considered a 50 amp load when sizing circuits and equipment.
• In a smaller commercial building, installing 12 of these chargers, evenly balanced across the phases, would require 346 amps at 208Y/120V, 3-phase or 150 amps at 480Y/277V, 3-phase to be considered the total load of the EV chargers—a significant increase for a small building.
• In a condominium building with 300 units, installing one of these chargers for each unit would require 8,660 amps at 208Y/120V, 3-phase or 3,753 amps at 480Y/277V, 3-phase.  These values would require two 208Y/120V, 3-phase services or one 480Y/277V, 3-phase service dedicated to the EV chargers.
• If each of the 300 condominium units used a Tesla wall connector rated at 48 amps, requiring the charger to be considered a 60 amp load, the total demand would rise to 10,392 amps at 208Y/120V, 3-phase—highlighting the scale of infrastructure needed for full-building EV readiness.

EV Charging Systems with Load Management

In an effort to minimize the impact EV chargers can have on a power distribution system, the 2020 NEC contains a special provision that allows an automatic load management system to be implemented.  When an automatic load management system is implemented, the required calculated EV charging load is allowed to be the maximum load permitted by the automatic load management system.

An automatic load management system for a system of EV chargers is a software-driven system that can limit the total power drawn by the EV charging system, while simultaneously optimizing the charging for each charger.

If the small commercial building example above only had 200 amps available that could be allocated to EV chargers, the load management system would limit the total power drawn by the 12 chargers to some pre-programmed value of less than 200 amps, ensuring the building infrastructure will not be overloaded.  The load management system will also prioritize the chargers that have vehicles with a low charge state by maximizing the power given to those chargers, while reducing the power serving the chargers that are serving vehicles with a higher charge state.

Automatic load management systems do have their caveats.  An EV charger’s output power is directly related to the charger’s input power, meaning that the output power is reduced if the input power is reduced.  Electric vehicle charging times are directly related to the output power of the connected charger.  Therefore, when an automatic load management system reduces the power to an EV charger, the charging time associated with that EV charger will increase, which could lead to user complaints based on their experience at other charging facilities.  In addition, severely limiting the managed systems output to match the existing electrical service conditions often leads to a reduced total number of chargers that can be reasonably supported on an existing service.

2. Space Constraints for Electrical Upgrades

Space limitations, particularly in dense urban areas like Honolulu, create significant challenges for expanding EV charging infrastructure. While installing commercial charging hubs, like at gas stations, is feasible, space constraints become more pronounced when considering installations within buildings.

In new developments, architects and engineers must juggle competing priorities for space. Allocating room for electrical distribution and charging infrastructure near parking areas may result in losing valuable parking stalls. This tug-of-war over space often forces EV infrastructure to be deprioritized during value engineering efforts.

Retrofitting existing buildings is even more complex. Electrical rooms in older facilities are often too small to accommodate upgraded switchgear required for EV charging. If the building’s utility service needs to be upgraded, the new service must meet stringent requirements, such as encasing utility feeds in concrete—a near-impossible task in a fully built structure.

3. High Cost of Upgrading Electrical Services

The cost of upgrading utility services and installing EV infrastructure can be excessively high, especially for large properties. Retrofitting a condominium with sufficient capacity to support multiple EV chargers requires costly upgrades to services, electrical panels, transformers, and distribution systems.

With respect to new construction, designing to accommodate widespread EV adoption triggers enormous electrical service requirements, which are often cut during value engineering due to their high construction cost.

For older buildings, utility upgrades are often out of reach. If the electrical service was sized decades ago based on historical loads, there’s often little room to add charging stations without triggering a complete overhaul—an investment that many building owners are hesitant to make.

4. Limited Grid Capacity and High Demand during Peak Hours

As EV adoption grows, so does the demand for electricity—especially in the evening when most people charge their vehicles. Unfortunately, this is also when energy usage is already at its highest and solar production drops off, creating a mismatch between supply and demand.

Programs like demand-side management, demand response, and time-of-use rates weren’t created specifically for EVs, but their existence highlights a larger issue: There are already production challenges during peak hours. Utilities are actively working to manage demand, but the growing number of EVs will only increase pressure on the grid when it’s least equipped to handle it.

Without careful planning and infrastructure upgrades, the system may struggle to support the added demand from widespread EV charging during these critical hours.

5. Expectations and the Need for Clear Guidance

Installing EV chargers can seem straightforward at first glance, but large-scale implementation—especially in multi-unit residential buildings—often involves significant electrical and infrastructure considerations. Without a clear understanding of what’s involved, expectations around cost, feasibility, and timelines can differ from the actual requirements.

At the policy level, efforts to support EV adoption, such as rules that prevent condominium boards from denying charger requests, are a positive step forward. However, these policies may not always reflect the full scope of upgrades needed to support widespread charging in existing buildings. Clearer guidance can help all stakeholders—including property owners, developers, and policymakers—navigate the technical and financial realities of expanding EV infrastructure effectively and efficiently.

Conclusion: What Property Owners and Developers Need to Know

Understanding the impact of EV charging on electrical infrastructure is key to making well-informed decisions. With growing demand and evolving regulations, it’s important to consider the electrical load, space requirements, and cost implications early in the planning process.

EV charging projects can be challenging—but they’re far from impossible. With the right planning and support, these efforts can be successfully integrated into both new developments and existing buildings. Hiring experienced consultants early in the process can help you navigate technical and logistical hurdles, avoid costly surprises, and move forward with confidence.

Schnackel Engineers has decades of experience guiding clients through complex infrastructure projects. Whether you’re planning a new development or exploring options for an existing property, our team can help you implement EV solutions that are practical, scalable, and aligned with your long-term goals.

Ready to get started? Contact Schnackel Engineers today to discuss your EV charging project. Let us help you turn challenges into opportunities for long-term success.