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Are distribution feeders / substation ready for the impacts of Commercial EV implementation?

Howard Smith's picture
Retired - Manager of Distributed Energy Resource Policy, Retired from Southern Company Service

Independent Consultant that is monitoring, developing, and recommending policy and positions as it relates to distributed energy resources and grid edge technologies in support of the electric...

  • Member since 2003
  • 20 items added with 1,407 views
  • Jun 15, 2021

In my opinion, Commercial EVs (fleets, government agencies, local delivery systems, etc.) will be implemented by customers much sooner than the industry is willing to accept.  These CVEs will require a new level of reliability and resiliency with the likelihood of onsite renewable generation and storage and the potential need for microgrids.  The focus has been on residential/private EVs and long haul large Commercial EV trucks/fleets. 

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Commercial fleet electric vehicle charging infrastructure will be built by the owner on the customer side of the meter. The owner’s engineer will need to closely coordinate with the local distribution utility because fleet charging WILL impact the legacy distribution grid.  

Utility engineers will need to study the charging impacts and modify their grid accordingly.  This may require line upgrades or additions and modifications to one or more local substations....all depending on the size (load) of the fleet charging customer and the level of reliability that the customer demands.  The grid will deliver great reliability (typically 99.97% average across the country) and can deliver “resiliency” by means of hardened structures or underground. 

The utility grid will also connect the customer to low cost renewable generation as available and, therefore, there is no need for an expensive and “hard to run” microgrid.

Electric utilities have not prepared for the impacts of widespread, commercial EV facilities.  They continue to live in the past and utilize the framework established in the early 1900’s by Samuel Insull, Nikola Tesla, and other pioneers of the electric power industry.  Electric utilities need to develop a strategy to deal with the widespread conversion of industrial processes and residential loads to electric energy consumption.  EV’s are just one of many.

An innovative electric utility will propose a commercial EV billing structure that is a win – win for everyone.  For example, an innovative electric utility will develop

  1. A monthly infrastructure charge, such as $10 per KW
  2. A monthly consumption charge, such as $10 per KW
  3. A daily interruption credit, such as $1 per KW
  4. A daily electric grid support credit, such as $1 per KW

For a commercial EV facility with a peak demand of 500 KW, the monthly electric bill would be:

  1. Monthly infrastructure charge     $5,000
  2. Monthly consumption charge      $5,000

If extreme cold weather occurs and the electric utility needs to reduce consumption, the EV facility could reduce consumption to 250 KW and receive a credit

  1. Interruption credit, 3 days              ($750)

If energy shortfalls occur and the electric utility needs to utilize EV batteries as an energy source, the EV facility could provide 250 KW to the electric grid and receive a credit

  1. Electric grid support credit, 3 days   ($750)

With this scenario, commercial EV facilities will be able to support the electric grid and electric utilities will be able to utilize EV facilities as part of their energy control process. 

Electric utilities, their engineering firms, and their consultants need to adopt the mindset of innovators, namely, they need to recognize that industry leaders anticipate, and prepare for, change.

Dr. Amal Khashab's picture
Dr. Amal Khashab on Jun 21, 2021

For EV and all other futuristic conversion into electricity users, it is just a mater of loads in MW need to be supplied safely and continuously. Therefore supply - demand balance still the main issue. Utility can anticipate electricity demand and execute projects to secure supply . It will beneficial if all concerned stack holders sharing their plans with utility. After that they can sit together discussing the appropriate tariffs. I mean one cannot start with tariffs .

Tony Sleva's picture
Tony Sleva on Jun 22, 2021

The existing tariff structure is inappropriate for tomorrow's energy system.  Samuel Insull developed KWH billing structures almost 100 years ago.  Electric utilities need to change these rate structures.

I have rooftop solar panels.  This means that my host utility loses money every month that they provide electric service to my house.  If they try to change their rate structure now that I have invested in solar panels, I will file a brief with the public utility commission that challenges their request for a rate increase.

Electric utilities need to recognize that similar issues will arise with commercial EV implementation unless they think long term and develop a win-win strategy.

Supply-demand balance is an issue that will be overridden by cost factors.  Interruption credits and grid support credits will allow commercial EV facilities to participate in maintaining the supply-demand balance during times when the power grid is stressed.

The rolling blackouts and price spikes in California in August 2020 and in Texas in February 2021 are clear signs that past practice needs to change.  Commercial EV facilities will contribute to the needed changes if economic incentives are placed on the bargaining table.  That's why need to start with new rate structures.

Jens Dalsgaard's picture
Jens Dalsgaard on Jun 22, 2021

I agree.
Utilities need to change their way of thinking.
I recently did an article on this in which I present my view on the challenges and the approaches needed:

I would imagine that the answer you have is accurate. The implementation in systems management is doable already, but the hardest backlash will be employment and job cuts which the energy industry is not willing to let happen. Actually, I have been wondering if re-training and cross function job roles wouldn't be one of the best decisions the energy industry could make.

I think that utilities have  to make a master plan for commercial EVs include sizing and locations. Then it has to be superimposed as additional loads on the existing feeders and substations. If enforcement is needed , the required fund has to be allocated. TOU tariff could be applied to maximize RE consumption out of the peak hours.

Tony Sleva's picture
Tony Sleva on Jun 22, 2021

Utilities will have little influence in sizing and locating commercial EV facilities unless they learn to think like executives at trucking companies. Amazon Logistics, UPS, USPS and others with fleets of EVs will locate their EV facilities near their existing distribution centers.  These companies will purchase sites within one mile of their existing distribution centers in order to minimize drive time costs from charging stations to loading docks.  

Long haul trucking companies will locate EV Facilities near their hubs.  Areas such as Troutdale, OR; Harrisburg, PA: and Edwardsville, KS with existing long haul truck terminals will have little choice but to accept commercial EV facilities.

Many years ago, executives at Lakeland Electric in Florida worked with Publix so that Publix would maintain their distribution center in Lakeland.  That's the type of teamwork that will be needed for EV facilities.

In short, it depends. The first step that utilities must understand is extensive EV growth is inevitable, which most have. However, the argument revolves around how quickly. Next, you can get a pretty good idea by asking if they have an EV rate that shifts consumers' charging off-peak where additional grid capacity exists. Building additional capacity will be required subsequent to leveraging TOU rates. TOU rates can be targeted to increase the load factor relatively easy by leveraging an AMI system to bill off interval reads. So, if utilities are having these conversations and implementing some of these strategies they will buy ample time to adapt CEV in my opinion.

I don't know if all the utilities are prepared because I suspect distribution companies in states that have integrated distribution planning or grid modernization dockets have an upper hand in terms of identifying feeders that have "hosting capacity" to reliably interconnect distributed energy resources including solar and commercial EV fleet load.

In my opinion, an utility can pro-actively show hosting capacity analysis on feeders where it makes most sense for commercial EVs to interconnect.

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