Right-Speeding EV Charging

Foreword

This report is directed primarily at local and other governmental agencies who may have or be considering requirements for EV charging in parking facilities. While US EV sales have recently declined due to the end of Federal tax credits, most industry experts believe the cost of electric vehicles will come down further and be cost-effective without incentives. According to Mary Barra, CEO of GM, electric vehicles "are still the end game." The industry needs rational guidelines to make parking "EV Ready." This report may also be useful to individuals involved in the planning, design, construction, operation, management, or approval of parking facilities.

This document is the result of work led by the author, in consultation with and peer reviewed by the 40+ members of the Parking Consultants Council. It represents their work but should not be considered inclusive of technical requirements or industry standards; it is for informational and discussion purposes and is not legal advice.

Types of EV chargers in parking applications

* Costs vary by charger type, features, and particularly new infrastructure required.   ** L3 per SAE is over 400 kW; no car sold in the US today can accept it -- it serves heavy trucks and buses. There will never be an "L4," despite current misuse of both terms.

Terminology that matters

As happens with new technology, terminology evolves and eventually settles. The paper recommends the most settled set: EVSE is the entire charging system from transformer to connector; the charger is the device that transfers power, with its ports, software, and payment functionality; a port charges one EV; and an EV station -- akin to a gas station -- is a grouping of chargers, charging spaces, and the vehicular access to them. The station definition is critical for accessibility: the Access Board applies its required-accessible-charger table to each station, not to the entire parking facility.

Three more terms are defined differently in local codes and frequently misused. The paper's settled versions:

PCC recommends against installing receptacles at EV Ready stalls: NEC requires special waterproof receptacles that create tripping hazards at four-corner locations and cannot serve accessible spaces, and open receptacles let owners charge without the property's knowledge and without the safety features of chargers meeting NEC, SAE, UL, and ISO standards. EV Ready should be designed as a future charging space, not a usable one.

Right-speeding

The National Renewable Energy Lab strongly recommends "right-speeding": determining the kW per port from the users -- the miles they typically need during recharge and the length of the parking stay.¹

Right-speeding is not only the right kW but the right number of ports. Excessive infrastructure for future ports produces an initial cost with no return for many years -- and demand for that many charging spaces may never materialize. Too many kW per port produces cars parked at chargers far longer than they draw power: if all employees plug in at shift start but draw for only an hour or two, excess kW per port inflates the service load and the simultaneous draw on the grid, while the cars cannot or will not move when charging completes. For the sake of the grid, and to eliminate unnecessary expense, every installation of chargers in parking facilities should be designed by right-speeding.

Why more is not always better

Many in the parking industry are concerned that the burden of providing community EV charging is being placed on the owners of new parking facilities -- with no subsidy, and far earlier than demand justifies. Many jurisdictions require only EV Ready or EV Capable at fairly reasoned levels. Others go much further: Boston requires certain new facilities to equip 25% of stalls with chargers today and make 100% EV Ready -- roughly five times the PEVs on the road in Boston, many of which will never charge at that facility. One can confidently say chargers will never be needed at 100% of stalls for any use other than residential. Atlanta requires 20% installed (25% city-owned) and another 20% EV Ready, all at 9.6 kW per port -- and there is no known land use that requires 9.6 kW per port for Level 2.

Requirements at these levels force capital that cannot pay back for decades and risk waste as technology evolves: roughly half the cost of EVSE is the EV Ready infrastructure. They also risk backlash among users who otherwise support sustainability -- what happens when the only stall available to an ICE vehicle is a charging space, because the supply available to it has been cut by a quarter? Jurisdictions that require chargers today should require a reasonable number, and should enact use provisions letting law enforcement ticket vehicles illegally parked in EV charging stalls on private property, as accessible-parking law already does.

Where the market actually is

PEV sales growth slowed in 2024 and declined in 2025, driven by Federal policy changes -- the end of tax incentives and tariffs disproportionately affecting PEV costs. The sales mix moved toward non-plug-in hybrids: BEVs down 4.6% year over year, PHEVs down 22%, HEVs up 23.5%. The announced end of credits pulled purchases into August and September; measured across the months without subsidies, market share appears to be stabilizing near 6%. Buyers are concerned with fuel mileage and sustainability -- they just are not comfortable with PEVs yet.

Why EVs and AVs are inextricably linked

Robotaxis may travel 100 or more miles per day and 100,000 miles per year; nearly all autonomous vehicles used for shared rides will be electric and reported as passenger-vehicle sales. In the near term, fleet purchases are expected to prop up EV sales. As robotaxi demand grows, two facility types emerge: a home base for overnight recharge, cleaning, and maintenance at the perimeter of dense areas, and daytime waiting zones -- multiple, convenient off-street locations where vehicles charge while holding between calls. Ideally both charge autonomously: the vehicle talks to the station's scheduling app and moves itself to a charger when one opens. Robot connectors and wireless pads are both in development. The big benefit: one charger serves many vehicles at far better utilization, reducing the chargers needed anywhere cars park longer than they charge.

Walker has tracked the AV impact on parking demand since 2015. The 2026 update pushes both AV and EV adoption five to six years later than prior projections, compounded by the Census Bureau's reduced population outlook. PEVs on the road in 2030: 6.5% in the base case (down from 7% projected in 2022), 7.2% under high mobility disruption -- higher share, but fewer total vehicles, as each robotaxi replaces several owned cars.

The NREL 2030 projection, read correctly

The key point: the need for Level 2 charging in parking is very low. Even in NREL's aggressive scenario -- built on prior-administration climate goals and at least a third above Walker's high case -- roughly 2% of all ports needed nationally are at multi-family residential and workplaces, under 4% at all other parking destinations, and 0.65% DCFC. 93.5% of all ports are needed at single-family homes. Tariffs and lost incentives shift even that further out: NREL's 2030 number may describe 2040.

What we do not know about 2030, much less 2050

Rapid technology change makes it difficult to plan EV Capable and EV Ready infrastructure today. Cars may charge faster or go farther at the same kW. Solid-state batteries -- "the holy grail"² -- may reach the public between 2027 and 2030, with longer range, faster charging, and better fire stability; a prototype-equipped Mercedes EQXS drove 745 miles without recharging in 2025. Higher-voltage architectures may make everyday DCFC cost-effective and safer, moving daily charging to gas-station-like locations and reducing destination charging further. Autonomous parking plus automated charging could let 10% of stalls with chargers serve 40% or more of parked cars per day. Today's chargers have a 7-to-10-year life but may be obsolete sooner, and improved load management at replacement can multiply what today's service assumptions support. And above all: PEVs do not need to charge every time they park. Even at 100% PEVs on the road, the vast majority will charge at home at night.

The rate of charging, and a special case

Right-speeding tailors delivered kW to adequate miles in the typical time parked. The paper's working rate is 3.1 miles gained per kW, from 2024 BEV models weighted by 2023 sales using DOE efficiency ratings -- a reasonable rate for the next ten years and the life of chargers installed today. The average car drives about 13,500 miles a year per FHWA: 37 miles a day, the number that anchors residential and workplace charging.

The airport case makes the argument by itself. Three months of dashboard data from an airport terminal deck -- four Level 2 ports at under 1% of spaces, at the moment more chargers seemed needed: 109 sessions across three months, nine sessions per port per month. Average stay: 50 hours. Average charge: 5.9 hours. Cars were connected 63% of the time and drawing power 12% of the time parked -- charging-time utilization of about 7.5%. The spaces looked full; the chargers were nearly idle.

The airport survey

To size airport public charging, the paper develops a metric: percent of charging spaces per 1% of PEVs on the road in that state. California -- with statewide requirements since 2013 and aggressive PEV goals -- tops the table at 1.35%; most airports, including several in high-PEV states, sit far below a quarter of one percent.

State PEV registration source: afdc.energy.gov/vehicle-registration

Recommendation: for facilities over 200 spaces, provide chargers at 0.2% of spaces for each 1% of expected PEVs on the road in the design year (roughly two years after installation). Colorado at an expected 2.5% on the road: 0.5% of spaces. A California airport at 5%: 1.0% of spaces.

The recommendations: right kW, right count

Recommended kW per port follows typical distance traveled and time parked, in six land-use groupings. kW per port is the maximum the breaker delivers; dual-port devices share power, and shared ports plus automated load management across devices reduce the total service load as NEC permits.