By Terance J. Harper, M.S., NABCEP May 4, 2021
Over the next 10 years, electric vehicles (EVs) are expected to increase their share of the automobile market significantly. According to a report from Deloitte, its “global EV forecast is for a compound annual growth rate of 29% over the next 10 years
[with] total EV sales growing from 2.5 million in 2020 to 11.2 million in 2025 and reaching 31.1 million by 2030.”
With such exponential growth expected in the EV market, the question of how to keep all those vehicles charged without relying on fossil-fuel produced electricity is emerging as a central concern for homeowners and businesses across the country. As more residential and commercial buildings decide to add EV chargers to their properties, many of them are choosing to marry their EV charging stations with solar installations.
The synergy is obvious. EVs are designed to lower the transportation sector’s carbon emissions, while solar installations are designed to reduce the carbon footprint of electricity production. Most importantly, the two technologies are easy to integrate, making them cost-effective for projects where saving money is at a premium.
In this article, we will discuss the current state of the EV charger market, how to choose the type of electrical panel necessary to support EV charger networks, and why engaging an engineering firm early in the process is essential to getting the job done right.
The Current State Of The Market Is Strong (And Growing)
As more consumers gain access to EVs, the push for increased charger accessibility is coming from the EV owners themselves. In particular, luxury apartment tenants are demanding that their buildings add EV chargers to their garages.
As a result, apartment landlords (particularly ones for luxury apartments) are retrofitting their older parking structures — or building new parking garages — with upward of 10 or more chargers, an increase that indicates significant changes are occurring (specifically, Illumine-i has seen luxury apartment owners in Arizona, in particular, take heed of this burgeoning trend).
Recent reporting suggests that the Biden Administration has proposed $174 billion to support EVs and the necessary charging network, including up to 500,000 new EV chargers. The spending would be made through grants and tax incentives, which could lead cities to start mandating EV chargers in their buildings (though we have not seen any specific moves in that direction yet).
Single-Phase Vs. Three-Phase Design
Adding EV chargers is an enormous, positive step forward as the U.S. vehicle fleet
transitions away from internal combustion engines. As more homeowners consider adding chargers to their properties, however, it’s essential to take the capacity of the property’s electrical panels into account. That’s why we recommend only doing one to two EV chargers at most residences because these chargers can be considerable extra loads on single-phase electrical panels.
A competent design engineer will do the appropriate load calculations to make sure there is no overloading of the residential circuits. For commercial applications, the EV charger load becomes too large for a single-phase panel to handle, the engineer might recommend the inclusion of a multiphase unit into the overall building design.
When installing single-phase chargers for commercial type installations, three-phase electrical panels should be used. This results in a smaller overall panel rating, which means cost savings for the overall project. In addition, depending on the on-site voltage, a three-phase panel will eliminate the need for a step-down transformer.
For example, EV chargers have an input of 208/240 VAC 60Hz single phase. For 10 EV chargers requiring around 32 A of current, a 240-V, single-phase panels will produce a higher total proposed load than if a 208-V three-phase panel was used.
In most cases, commercial garages have electrical systems at 208-V three-phase panels or 480-V three-phase panels, requiring a step-down transformer to 208 V at one of the voltage inputs for the EV chargers. With this electrical setup at the 208-V three-phase current, still requiring 32 A of current produces a total proposed load that allows a smaller-sized electrical panel.
Such construction saves money on the overall project without cutting the current output to the EV chargers. In three-phase panels, the EV chargers should be balanced across the three phases, and load calculations should be included for all panels upstream to the main panel that are affected.
Typically, we see homeowners ask for EV chargers in the residential market as complements to the solar projects because it is easier to bundle the two, either as a solar + storage or a solar + EV charger project. Though we see many EV chargers being added to garages and parking lots, we believe eventually you will see an uptick in special sections of apartment building parking lots where residents can park their EVs.
Why An Engineering Firm Is A Must
Particularly in retrofit situations (whether they’re residential or commercial buildings), an experienced engineering firm is a must. Building owners should partner with firms that can provide site-load and arc-fault calculations along with permit-ready plans for construction. They should also choose companies that can design systems with any EV charger in the market to not be locked into one company’s technology.
They should also find firms that can speed turnaround times to speed project approval, which will help keep the budget on projects lower. Finally, the company should have the relevant experience — commercial or residential — to the project at hand.
EVs are expected to become the vehicle of choice over the next decade as prices continue to decrease. With that spread, the number of EV chargers will have to grow exponentially and keep pace with demand. As you plan your parking lot or garage, you have to ask yourself — will your project be ready for the EV revolution?