Optimizing the Road to Electric Transit

As transit agencies accelerate transition to battery-electric bus fleets, many are discovering that electrification introduces a complex set of questions around energy supply, infrastructure and fleet sizing, operating costs, long-term scalability and the heavy upfront capital investments that are needed.

To help agencies across North America navigate those challenges, WSP has developed an in-house Microgrid and Electric Vehicle (EV) Fleet Charge Management Optimization Tool designed specifically for transit fleet electrification planning. The tool also supports microgrid and energy projects across a wide range of industries.

The tool models and optimizes how microgrids, batteries and EV fleets use energy, helping agencies identify the most efficient and long-term cost‑effective strategies for charging, discharging and sizing infrastructure over time. The goal is to provide as much clarity on the return on investments depending on the scenarios being considered prior to making any capital commitments. The tool allows for better planning and right-sizing of both the fleet size and the supporting infrastructure.

On the charge management side, the tool can evaluate different scenarios, with or without a microgrid or renewable energy sources, and conduct planning, measure the facility’s connected and utilized load, carry out operational feasibility studies, and analyze the workflow. The tool also assists in properly sizing a fleet, particularly through its charge management module. The tool is capable of providing various options depending on operational, design/constriction phases or financial constraints.

By simulating real‑world operating conditions and utility costs, it gives agencies clear insight into infrastructure needs, long‑term savings and resilient electrification strategies.

Sina Mirzaeisefat, vice president, program manager of electrification at WSP in the U.S., explained how the tool brings clarity to decisions that can otherwise feel overwhelming for agencies facing aggressive decarbonization goals.

WSP began developing its microgrid optimization platform after years of working with commercially available software and custom spreadsheets. While those tools could handle pieces of the puzzle, they often failed to capture the full picture required for transit projects.

“Many of those tools could not model complex battery operations, ignored battery degradation over time or were unable to simulate real-world depot loads that include facilities, chargers, solar generation and grid interactions,” Mirzaeisefat said.

The result was a planning gap at precisely the moment agencies needed reliable answers.

To address the challenge, WSP launched its Microgrid Simulation and Optimization Tool in 2022. In 2025, the firm expanded its platform with a dedicated Charge Management Module, creating an integrated tool that links energy generation, storage and electric bus charging into a single planning framework.

At its core, the platform is designed to answer one essential question: What is the most cost-effective and reliable way to power an electric transit fleet today and in the future?

To do that, the tool combines two complementary capabilities.

The microgrid optimization component models solar PV, battery energy storage systems (BESS), generators and grid connections.

“It simulates hour-by-hour charging and discharging behavior over one year or multiple years, accounting for utility tariffs, demand charges and battery degradation,” Mirzaeisefat said. “It models battery augmentation strategies, helping agencies understand when additional capacity may be needed to maintain performance over time.”

The charge management optimization component focuses on fleet operations. It simulates daily and annual charging schedules for electric buses, evaluates charger utilization and estimates annual energy costs and fleet mileage. Agencies can test different scenarios — varying fleet size, charger power or depot layouts — to determine what is technically feasible and financially sustainable.

Together, these capabilities allow us to evaluate how energy flows through a transit facility, from generation and storage to EV charging and facility loads.

Transit electrification projects are often grid-tied and subject to time-of-use rates and demand charges. Without careful planning, agencies can unintentionally oversize infrastructure, under-utilize assets, or face higher-than-expected operating costs.

Our optimization tool helps avoid those pitfalls by identifying the most effective charging and discharging strategies for a given site.

“By shifting energy use away from peak hours, integrating solar generation and strategically deploying battery storage, agencies can reduce demand charges and improve return on investment,” Mirzaeisefat said.

Just as importantly, the tool provides transparency. To clearly see the cost and performance tradeoffs of each option, decision-makers can compare multiple scenarios, including different battery sizes, charger configurations or expansion plans.

The tool has already been applied across a range of transit and infrastructure projects, including Capital Metro (CapMetro) in Austin, Los Angeles Metro, Sacramento Regional Transit and the Nevada Department of Transportation.

In one CapMetro analysis, WSP used the tool to evaluate multiple battery storage sizes for a solar-powered depot. By comparing capital costs, annual utility expenses, system reliability and achievable electric bus mileage, the agency was able to identify an optimized configuration that balanced performance with cost.

A key advantage of our approach is the ability to look beyond current operations. Transit agencies rarely electrify their entire fleet at once. Routes are added, depots expand and charging needs evolve over time.

“Because the tool can simulate operations over multiple years, agencies can test future scenarios alongside today’s requirements,” Mirzaeisefat said. “This helps ensure that infrastructure investments made now will still support fleet growth five or 10 years down the line.”

Unlike off-the-shelf software, the Microgrid and Charge Management Optimization Tool was developed in-house and tailored to consulting workflows. It is particularly valuable during early planning and feasibility phases, when agencies need credible, data-driven insights without committing to full operational software platforms.