Judging from the early sales figures, electric vehicles have been getting more press than purchases, but the market for equipment to charge plug-in cars has the attention of the nation’s electric utilities.
The impact of electric vehicle supply equipment (EVSE) on the electric grid has been a point of contention for some time, with some claiming that a proliferation of EV charging could cause serious trouble for power distribution systems while others predict that the potential for utilities to use car batteries as distributed energy storage could be the salvation of renewable energy and smart grid efforts.
A new report released this month by the Edison Electric Institute (EEI) offers power companies a roadmap for evaluating electric vehicles’ potential impact on their service areas and promoting the adoption of electric vehicles among their customers. In The Utility Guide to Plug-In Electric Vehicle Readiness the EEI lays out what utilities need to consider and who they need to get on-board to make the most of the opportunities presented by EVSE.
The opportunities involved are substantial, said the EEI report. “Utilities have an important role in supporting, encouraging, and enabling this technology. Moreover, the strategic value of integrating electric transportation into your overall corporate goals and objectives is substantial — from new business opportunities, to operational and system benefits, to improved customer satisfaction. Utilities should engage now to shape the future of this market and prepare for being the transportation fuel providers of the coming decades.”
Actual plug-in electric vehicle (PEV) adoption by consumers has lagged behind the predictions of automotive manufacturers for a variety of reasons, depending on whom you ask. The price of the vehicles puts them beyond comparable vehicles powered by internal combustion engines, even with government incentives; concerns about vehicle range and the availability of charging stations are causing some interested buyers to hold off until the technology is more mature; uncertainty about resale value and some recent news about concerns over battery fires have further slowed adoption. Nonetheless, the surge of announcements by auto manufacturers that they will introduce new electric-drive or plug-in hybrid models over the coming year or two suggest that the manufacturers, at least, expect these concerns to dissipate. And while the consumer vehicle market gets most of the attention, the adoption of PEVs in commercial fleets and industrial applications may present the greater short-term market potential for electrified transportation.
Electrical equipment manufacturers are certainly stepping up to do their part to make sure there are plenty of options for charging those electric vehicles that do roll onto the streets. In a July 2011 study by the Electric Power Research Institute (EPRI), Transportation Electrification: A Technology Overview, researchers found 37 companies that say they have EVSE equipment. EM’s search didn’t find that many, but a who’s who of heavy hitters in the electrical equipment market do offer EV supply equipment, among them GE, Siemens, ABB, Schneider Electric, Leviton, Legrand, Cooper Industries, Eaton and Milbank.
EEI’s paper draws on the experiences of first-adopter utilities to present a step-by-step process for getting up to speed on EVSE, including recommended staffing levels; options for adding electric vans, bucket trucks and other equipment to their service fleets; recommendations on public-outreach, promotions and incentives to encourage customers to consider PEVs; government officials and industry players they’ll need as allies; guides and references for evaluating their local distribution grid’s readiness to handle the loads from charging equipment; and preparing for future developments in the technology such as “smart” charging programs and vehicle-to-grid communication and energy storage possibilities.
Perhaps the most important issue right now is how the addition of residential and commercial EVSE loads will affect the power grid. The July EPRI study took a deep look at how clusters of new EVSE installations may affect utility operations and found that the load added to electrical grids by EV charging is not likely to cause any significant problems for utilities. “Even without smart charging the load of vehicle charging is relatively well distributed,” the study said. It found that even though we can expect a surge of PEV power demand when people get home from work between 5 p.m. and 6 p.m. “In this projection, PEV demand peaks at 5 p.m. and averages approximately 720W per plug-in vehicle due to the diversity in the aggregate load... Overall, feeder load growth is expected to increase only slightly due to PEV adoption.”
EPRI found that on older systems the addition of EVSE loads may require upgrades. “The short-term impacts for most utilities’ studies should be minimal and localized. There is a possibility, however, of isolated impacts on some distribution transformers and secondary drops, particularly in neighborhoods with older distribution systems, including underground systems.”
Even though the impact on the grid is likely to be mild and manageable, EPRI advised utilities that delays in addressing problems that do arise will cause problems, so it’s better to get ahead of the curve.
“EPRI believes that potential stresses on power delivery systems can be mitigated through asset management, system design practices, controlled charging of PEV, or some combination of the three. But again, given the likely variability in customers’ PEV choices, car types, varied charging patterns, varied charging speed preferences, and variable participation in utility-centric TOU (time-of-use) charging options, we believe that the utility will not be able to manage this risk in an ex post fashion.
“In many cases, the utility will likely not be notified or aware of a PEV addition, or a unique charging pattern. As such, a proactive risk mitigation strategy is recommended to remove localized risk to the distribution system. Controlled charging can significantly reduce PEV loading impacts on the distribution system, but is not likely to be universally adopted. Tariffs and rates which encourage nighttime charging (e.g., load management, valley-filling, etc.) can also help to avoid or postpone upgrades. All of these factors can be taken into account in the analysis of potential risk as a function of distribution system conditions and geographic factors.”