The strategic location of electric vehicle charging stations could help solve some of the impediments to more widespread adoption of the technology, according to a study by researchers from the Massachusetts Institute of Technology.
The study, Strategies for beneficial electric vehicle charging to reduce peak electricity demand and store solar energy, set out to address and find potential solutions to two problems posing obstacles to more widespread electric vehicle adoption.
The report noted that while combatting climate change involves plans for increasing vehicle electrification using renewable energy sources, some projections show those plans could require costly new power plants to meet peak loads in the evening when drivers plug in their cars. In addition, the report noted that over production of power from solar farms during the daytime can waste electricity-generation capacity.
To address those problems, the study’s authors investigated mitigation strategies that do not require travel behavior change or new technology such as vehicle-to-grid capabilities and networked chargers. They found that delayed home charging nearly eliminates increases in peak evening demand and that workplace charging can reduce peak demand while cutting the curtailment of photovoltaic electricity by half.
Those approaches could be combined to suit local conditions and decarbonization plans, the authors said, though they noted that capturing the benefits from those strategies would require “an acceleration of electric vehicle adoption relative to current rates.”
For the study, the researchers used anonymized data collected from two sample cities, New York and Dallas, showing when, for how long and where the electric vehicles were used.
Analysis of the data showed that better availability of charging stations at workplaces could help soak up peak midday power produced from solar power installations that might otherwise go to waste because it is not economical to build enough battery or other storage capacity to save all the power for use later in the day.
For delayed home charging, the study specified that each electric vehicle charger could be accompanied by a simple application to estimate the time to begin its charging cycle so that it charges just before the vehicle is needed the next day.
That approach, the authors noted, would not require a centralized control of the charging cycle and would not need communication capability between devices, but it would require some advance commitment on the part of participants.
By “home charging” the researchers include charging equipment in individual garages or parking areas, as well as charging stations available in on-street parking locations and in apartment building parking areas.
The findings highlight the value of combining the two approaches, the authors said, noting that delayed home charging can be a particularly effective component of a strategic package of charging locations. Workplace charging, they said, “is not a good substitute for home charging for meeting drivers’ needs on all days.”
The reason delayed home charging works so well, “is because of the natural variability in driving behaviors across individuals in a population,” Jessika Trancik, a professor at the Massachusetts Institute of Technology’s Institute for Data, Systems and Society, said in a statement.
There is a lot of public money going into expanding charging infrastructure, so it is important that incentives go toward locations that are efficient and effective and that do not require a lot of additional capacity expansion, Trancik said. "I think one of the fascinating things about these findings is that by being strategic you can avoid a lot of physical infrastructure that you would otherwise need," she said. “Your electric vehicles can displace some of the need for stationary energy storage, and you can also avoid the need to expand the capacity of power plants, by thinking about the location of chargers as a tool for managing demands – where they occur and when they occur.”