There is no doubt that the number of electric vehicle (EVs) on U.S. Roads is increasing. Tesla sells an average of five hundred Model S cars every week, mainly in California, and particularly in the San Francisco Bay Area.
Moving from first adopters to early adopters presents many challenges, before we even turn the conversation to mass adoption.
- Charging infrastructure challenges
- Levels of charging and standards
- Customer demand, similarly to gasoline-fueling: charge when you want / charge when you need to.
Add to that utility challenges with energy capacity, distribution, reliability, and responsiveness to peak-demand events. EV mass adoption would have a major impact on the electricity grid distribution, capacity management, and the costs associated with required system upgrades.
Adam Langton, Energy Regulatory Analyst at the California Public Utilities Commission (CPUC), discussed the challenges utilities face with adoption of electric vehicles (EV) at the Energy Storage North America (ESNA) conference in San Jose, CA last week.
To understand the complete picture of what utilities are faced with, Mr. Langton described the traditional residential system upgrade policy utilities companies follow: local electricity distribution in a neighborhood is a shared resource that is sized to current load, at any given day. New customer load, or new loads that are added to the system (such as, property additions, new equipment at the home, a new swimming pool or a jacuzzi, etc.) increase the energy draw, and, therefore, involve utilities to evaluate the additional load. If the transformer needs an upgrade due to the increased load, some of the costs are passed on to the customer that created this new demand.
When EV charging came on the map, it impacted amps capacity and distribution, increasing the vulnerability of the energy grid. For years, upgrades were assigned under common facility treatment, which means that when a user buys a new plug-in EV (PEV) and plans to charge the car’s battery at home, there is a risk associated with an additional system upgrade cost, that is hard to quantify up-front and is sometimes hidden from the buying process. Often, PEV buyers don't know the consequences their charging may create, which might result in local grid upgrades, in transformer costs, etc. Further, customers don’t always notify utilities of the impending increased usage, although they are required to do so. Once the utility company evaluates the system, if an upgrade is needed, then the customers involved need to pay for the load upgrade. But who pays for what? What if the extra capacity needed is a result of several neighbors? What if the first two PEV owners do not require an upgrade, but then the third neighbor’s vehicle ‘tips the capacity point’? Does this last customer is the one to be footed with the bill of the costly amps upgrade for all three neighbors?
It is important that stakeholders understand the policy landscape, since EV adoption can create challenges in electricity distribution and the cost of capacity upgrades presents a potential obstacle in mass consumer adoption.
Langton provided utility load research that was done in 2012:
Less of 0.03% of all residential EV charger installations resulted in an upgrade. Out of the 6300 installations, only 9 contributed to the grid capacity in a way that required an upgrade to the distribution system.
Although this was a significantly low outcome, the number of EVs in 2012 was small and it is hard to predict the impact once more vehicles travel on our roads. In planning ahead, some utilities have already started the process of developing circuits upgrades in foreseeing the increased PEV urban charging demands.