Wireless electric vehicle charging on streets uses electromagnetic induction to transfer power without physical connectors. A primary coil, embedded in the road surface, generates an alternating magnetic field when energized by an external power source. A secondary coil, installed on the EV’s underside, captures this field, inducing an electric current that charges the vehicle’s battery. Efficient power transfer requires precise alignment between coils, often aided by sensors or magnetic guidance systems.
Operating typically at frequencies of 20–100 kHz, the system ensures safe, non-contact energy transfer with efficiencies up to 90%. Power levels vary from 3.3 kW for slow charging to 22 kW or higher for faster systems. Infrastructure includes power inverters, communication modules for vehicle-grid interaction, and safety mechanisms to prevent electromagnetic interference or hazards. Dynamic charging, where EVs charge while moving, extends this concept using sequential coil activation along roads.
The 2020 National Electrical Code (NEC) contains significant revisions to Article 625 Electric Vehicle Power Transfer Systems. Free access to this information is linked below:
Mighty spirited debate. Wireless charging from in-ground facilities employing magnetic resonance are noteworthy. Other Relevant Articles:
Article 240: Overcurrent Protection: This article includes requirements for overcurrent protection devices that could be relevant for EV charging systems.
Article 210: Branch Circuits: General requirements for branch circuits, which can include circuits dedicated to EVSE.
Article 220: Load Calculations: Guidelines for calculating the electrical load for EVSE installations.
Article 230: Services: General requirements for electrical service installations, which can be relevant for EVSE.
Article 250: Grounding and Bonding: Requirements for grounding and bonding, which are critical for safety in EVSE installations.
Technical committees meet November – January to respond. In the intervening time it is helpful break down the ideas that were in play last cycle. The links below provide the access point:
We find a fair amount of administrative and harmonization action; fairly common in any revision cycle. We have taken an interest in a few specific concepts that track in academic research construction industry literature:
Correlation with Underwriters Laboratory product standards
Bi-Directional Charging & Demand Response
Connection to interactive power sources
As a wiring safety installation code — with a large installer and inspection constituency — the NEC is usually the starting point for designing the power chain to electric vehicles. There is close coupling between the NEC and product conformance organizations identified by NIST as Nationally Recognized Testing Laboratories; the subject of a separate post.
Edison electric vehicle | National Park Service, US Department of the Interior
After the First Draft is released June 28th public comment is receivable until August 19th.
We typically do not duplicate the work of the 10’s of thousands of National Electrical Code instructors who will be fanning out across the nation to host training sessions for electrical professionals whose license requires mandatory continuing education. That space has been a crowded space for decades. Instead we co-host “transcript reading” sessions with the IEEE Education & Healthcare Facilities Committee to sort through specifics of the 2020 NEC and to develop some of the ideas that ran through 2020 proposals but did not make it to final ballot and which we are likely to see on the docket of the 2023 NEC revision. That committee meets online 4 times monthly. We also include Article 625 on the standing agenda of our Mobility colloquium; open to everyone. See our CALENDAR for the next online meeting
Issue: [16-102]
Category: Electrical, Transportation & Parking, Energy
In his books, The Black Swan and Antifragile, Nassim Nicholas Taleb observes that freak disasters—rare, high-impact events—are unpredictable and often underestimated due to their low probability. He calls these “Black Swan” events, characterized by their extreme rarity, severe consequences, and retrospective predictability. Taleb argues that people and systems are overly reliant on normalcy and linear models, ignoring the potential for such outliers.
These disasters expose the fragility of complex systems, like financial markets or infrastructure, which are unprepared for extreme shocks. In Antifragile, he contrasts fragile systems with antifragile ones, which thrive under stress. Taleb emphasizes that freak disasters are not anomalies but inevitable in a complex world, urging risk management that accounts for uncertainty rather than predictability. He critiques overconfidence in forecasting and advocates for building resilience to mitigate the devastating effects of these unpredictable events.
We cover this ground, more than tangentially, in our activism in disaster management standards setting. Our coverage of this topic dates back to 1993 which the links below should reveal. We will expand upon this topic as more information is derived from this past week’s events in Kerr County Texas.
Bitcoin is developed under an open-source model and released under the MIT License. As an open-source project, the Bitcoin source code is publicly accessible, allowing users to examine, modify, and distribute it within the terms of the MIT License.
The term “lively arts” is attributed to American writer and poet James Thurber. It was popularized in the mid-20th century as a way to describe various forms of performing arts, such as theater, dance, music, and other creative expressions.
Curtain for the Lviv Theatre of Opera and Ballet
“What art is, in reality, is this missing link, not the links which exist.
It’s not what you see that is art; art is the gap”
— Marcel Duchamp
Today we refresh our understanding of the literature that guides the safety and sustainability goals of lively art events in educational settlements. Consortia have evolved quickly in recent years, leading and lagging changes in the content creation and delivery domain. With this evolution a professional discipline has emerged that requires training and certification in the electrotechnologies that contribute to “event safety”; among them:
ASHRAE International
Standard 62.1: This standard establishes minimum ventilation rates and indoor air quality requirements for commercial buildings, including theaters and auditoriums.
Standard 55: This standard specifies thermal comfort conditions for occupants in indoor environments, which can have an impact on air quality.
RP-16-17 Lighting for Theatrical Productions: This standard provides guidance on the design and implementation of lighting systems for theatrical productions. It includes information on the use of color, light direction, and light intensity to create different moods and effects.
RP-30-15 Recommended Practice for the Design of Theatres and Auditoriums: This standard provides guidance on the design of theaters and auditoriums, including lighting systems. It covers topics such as seating layout, stage design, and acoustics, as well as lighting design considerations.
DG-24-19 Design Guide for Color and Illumination: This guide provides information on the use of color in lighting design, including color temperature, color rendering, and color mixing. It is relevant to theater lighting design as well as other applications.
Dance and Athletic Floor Product Standards: ASTM F2118, EN 14904, DIN 18032-2
Incumbent standards-setting organizations such as ASHRAE, ASTM, ICC, IEEE, NFPA have also discovered, integrated and promulgated event safety and sustainability concepts into their catalog of best practice titles; many already incorporated by reference into public safety law. We explore relevant research on crowd management and spectator safety.
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Qualified Zone Academy Bonds (QZABs) are a U.S. government debt instrument created by Section 226 of the Taxpayer Relief Act of 1997. It was later revised and regulations may be found in Section 54(E) of the U.S. Code. QZABs allow certain qualified schools to borrow at nominal interest rates (as low as zero percent) for costs incurred in connection with the establishment of special programs in partnership with the private sector…
…Funds can be used for renovation and rehabilitation projects (including energy projects), as well as equipment purchases (including computers). QZABs cannot be used for new building construction. The school district must obtain matching funds from a private-sector/non-profit partner equal to at least 10% of the cost of the proposed project. Information on the two QZAB federal mandates, 10% match and academy, can be obtained by visiting the American Association of School Administrators (AASA) school financing toolkit (see resources below).
…The normal annual allocation each year has been $400,000,000. However, during 2008, 2009, and 2010, the American Recovery & Reinvestment Act (ARRA) increased these amounts to 1.4 billion. The 2011 allocation has returned to the $400,000,000 level. The allocation is divided up by all fifty states and US possessions. QZABs are a temporary program, subject to reauthorization. The last authorization was for the calendar years 2012 and 2013. Authorizations must be used within two years following the year for which they were given, meaning that authorizations given in 2012 must be used by December 31, 2014. As of July 21, 2014, the reauthorization of the QZAB program for years 2014 and 2015 has not been passed by the U.S. Congress. [Emphasis added*]…
…Schools usually fund large projects, like building renovation or construction, through debt mechanisms such as tax-exempt bonds or loans. School districts must then pay a substantial amount of interest on this debt. For schools serving low income students, QZABs reduce the burden of interest payments by giving financial institutions holding the bonds (or other debt mechanism) a tax credit in lieu of interest. The school district must still pay back the amount of money it initially borrowed, but does not have to pay any interest — typically about half the cost of renovating a school. The credit rate for QZABs sold on a given day is set by the Treasury Department…
With the COVID-19 pandemic disrupting education facility construction projects — and the prospect of at least 10 percent of the built environment rendered redundant for all time — it is enlightening to review the several sources of financing for these construction projects.
We review education industry construction project status and financing at least twice a month during our US Census Bureau Monthly Construction and Finance teleconferences. See our CALENDAR for the next online meeting; open to everyone. Use the login credential at the upper right of our home page.
New update alert! The 2022 update to the Trademark Assignment Dataset is now available online. Find 1.29 million trademark assignments, involving 2.28 million unique trademark properties issued by the USPTO between March 1952 and January 2023: https://t.co/njrDAbSpwBpic.twitter.com/GkAXrHoQ9T
