|About 50% of the more than 12,000 PEV owners in SCE territory charge at Level 1. Click to enlarge.|
Southern California Edison (SCE) released a white paper summarizing learnings from its Electric Vehicle (EV) readiness program. The paper, “Charged Up: Southern California Edison’s Key Learnings about Electric Vehicles, Our Customers and Grid Reliability,” shares information based on customer data and utility operations gathered since SCE began to prepare the distribution system and its customers for widespread electric vehicle (EV) adoption in its service territory.
Currently, SCE customers lease or own more than 12,000 plug-in electric vehicles (PEVs), both battery electric (BEVs, for about 35%) and plug-in hybrids (PHEVs, for about 65%)—about 10% of national EV sales. (SCE estimates that by 2020, there will be about 350,000 PEVs in its service territory.) Because California leads the nation in EV adoption, other utilities and stakeholders in the auto industry may find the information from the white paper useful, SCE suggested.
The Southern California region and SCE’s service territory in particular is seeing significant uptick of early plug-in vehicle adoption. SCE is partnering with auto makers, dealers and the communities we serve to help educate our customers on ways to seamlessly connect their new EVs to an ever-changing electrical system.—Ed Kjaer, SCE director of Transportation Electrification
SCE began its PEV readiness efforts in 2009, and quantified the anticipated impact of PEVs on the electric grid before consumers began buying and leasing them. Because “early adopters” tend to cluster in the same neighborhoods and adding a plug-in vehicle is like adding another house to the circuit, in terms of load, SCE developed an operational strategy to upgrade distribution circuits.
Over time, circuits need to be resized to match the changing needs of customers. Just as SCE now sizes its transformers to serve plasma TVs, it integrated the expected load from PEVs into standards applicable to its “grid modernization” efforts.
Since 2010, of all the nearly 400 upgrades made to (or identified for) circuits that serve PEV customers, only 1% of that work was required due to additional power demands from PEVs. The rest of the work was required under the regular infrastructure upgrade and maintenance schedule.
A residential circuit handles something like 7-10 homes; adding a plug-in is like adding an extra home to the circuit. We’re finding a very low incidence of infrastructure upgrade required because of plug-ins. There is nothing like doing upfront preparation to ensure that things go according to plan. When we anticipated the cars were coming, we did a huge amount of work analyzing the circuits, and anticipated where we’d see clustering of the vehicles. We incorporated the load analysis into our overal daily infrastructure actions. We’ve got a very good handle on the increased load from transportation—that’s just being incorporated into daily activities as we upgrade the system. We obviously have a very good handle on the characteristics of those vehicles.—Ed Kjaer
Current data shows that about 50% of PHEV drivers in the SCE territory charge at Level I (120 volts), resulting in a much lower impact on grid distribution circuits than if more customers charged at Level 2 (240 volts). With 70% of SCE PEV owners commuting 40 miles or less daily, many PEV owners can fully recharge at night at Level 1; SCE encourages PEV customers to charge up every night at home.
The paper notes one caveat—an increasing market share of BEVs coming with on-board chargers with higher capabilities (from 3.3 kilowatts to 6.6 kilowatts or even higher). This could create new implications for grid reliability, which SCE is monitoring, it said. SCE said it encourages its PEV customers to contact the utility for their charging needs, so it can ensure that local distribution circuits meet the additional energy demands of growing numbers of BEVs.
The paper also highlights the challenge with provision of a charging infrastructure to multi-family residences—e.g., urban dwellers without a garage for a charger. About half of SCE’s residential customers live in multi-dwelling units, such as condos and apartments. SCE research finds that despite high interest among condo/townhome owners and renters in purchasing a PEV within five years, fewer than 5% of building owners or condominium associations are even considering installing the necessary infrastructure.
One solution that SCE does not see as currently viable for the multi-family residence problem is the provision of fast chargers for convenient daily charging stations.
There is no question that we need to address the multi-family dwelling challenge. It’s not easy. Getting the infrastructure into those buildings, unless its brand new construction, is difficult. But I’m not sure fast charging really compensates for that—the cost to fuel the vehicle will be more expensive or comparable to gasoline. We’re talking about 480 volts—a big circuit. And you’re probably looking at demand charges on top of the basic cost.—Ed Kjaer
SCE summarized its other takeaways from the readiness program as follows:
Its approach to managing PEV-grid impact is meeting customers’ needs.
Using the “end charge” time programing feature (when drivers program their charging to be complete by a specific time) is better for grid reliability and neighborhood circuits. When customers set an “end charge” time for charging to be complete, they randomize the start time of their charging, which prevents a large number of vehicles from coming online at the same time—avoiding power-load spikes that potentially could affect the local distribution system.
When 15,000 SCE customers visit the SCE EV website monthly, about 46% make their first stop with the Plug-In Car Rate Assistant Tool, which helps estimate charging costs. Customers also click to find out more about public charging station locations from the link to the US Department of Energy’s map, watch videos on EVs and read background materials on environmental benefits and home electric infrastructure requirements.
Initial findings show early adopters of battery-electric vehicle (BEV) technology demonstrate consistent and predictable behavior. A sample of Nissan Leaf owners have indicated that any “range anxiety” had been eliminated after driving their new BEV over time. Most reported their overnight charging at 240 volts was sufficient to support their daily driving patterns.
Virtually all of the 180 cities in SCE’s service territory are committed to helping their residents plug in by streamlining permitting and inspection processes.
Looking ahead, Kjaer noted that PEVs could indeed play an important role in the provision of grid services in context of renewable energy integration and electric system load management.
That truly is the role of the utility. The grid is becoming much more dynamic. One of the advantages of this load from PEVs is that it is malleable. You can ramp it up, ramp it down, turn it on, turn it off. We have these large off-peak windows we deal with—9 at night to noon, say. I think that the utilities have the ability to manage this load at scale across the system. I do think that grid services will be important piece. We are a ways away yet, we are still building out the smart grid, and then ultimately getting to the point where the energy is omnidirectional. But there is no question that the cars have an important role to play.—Ed Kjaer