Electric vehicles (EVs) are key to decarbonizing transport. But if everyone charges their electric vehicle on their way home from work in the evening, it will put a huge strain on the power grid.
Meanwhile, solar power is key to decarbonizing the power grid. But while solar power generation is highest at midday, electricity demand tends to be highest in the early evening. Because of this mismatch, a large solar power ramp-up could contribute to all sorts of inefficiencies; for example, much of the solar electricity production could be “wasted” without the construction of expensive battery banks.
But these complex problems could have a simple and elegant solution, according to new research. Carefully strategizing the location of EV charging stations that people can use while on the go during the day, combined with encouraging people to delay charging EVs when at home home for the night, could virtually eliminate excessive strain on the grid, even with lots of EVs. on the road.
The researchers modeled hourly electricity supply and demand for two cities – New York, New York and Dallas, Texas – in a scenario with widespread deployment of electric vehicles and solar power. They based their analysis of the demand for electricity to charge electric vehicles on actual data from the two cities regarding when and for how long the vehicles were used versus parking at different locations.
If people make a habit of charging their cars while parked at work during the day, it would use midday solar output that might otherwise be wasted, the researchers report in the journal. Physical Sciences Cell Reports. In other words, the excess solar energy generated in the middle of the day can be stored in car batteries rather than in specially designed battery banks.
Charging at work will also reduce the increased electricity demand for car charging during the early evening rush hours. Another strategy to reduce this early evening surge in demand, the researchers suggest, is to set home chargers to finish charging shortly before you plan to leave home the next morning, rather than charging the car. right away. (Home chargers mean chargers wherever people park when they’re at home – on the street, in apartment building garages, etc. – not just dedicated chargers in the garages of single-family homes. )
The first of these strategies works because the behavior of many drivers is broadly similar: once at work, people tend to leave their car parked for hours on end. The second strategy works because the behavior of individual drivers varies: one person leaves for work at 6 a.m. and another at 8 a.m., for example.
Together, the two strategies can virtually eliminate the additional spike in early evening electricity demand due to widespread adoption of electric vehicles, the researchers calculated.
The results can give decision makers clues about where to focus or encourage the addition of EV infrastructuresay the researchers – for example, the widespread availability of free or low-cost charging at workplaces would encourage people to prioritize charging at work.
One of the main advantages of the strategies identified by the researchers is that they do not force people to change their driving behavior. Nor do they rely on expensive, unproven technologies such as equipped vehicles to deliver electricity to the grid or real-time communication and centralized control of chargers.
“These strategies may require only small design and regulatory changes, which may make them more likely to be adopted, and they may be effective even if introduced piecemeal at the local level and without full coordination. “, write the researchers.
In fact, researchers have found that charging in the workplace with less expensive and slower Level 1 chargers is about as effective in meeting driver needs as Level 2 chargers, while taking less energy. pressure on the network due to increased demand for fast charging when people commute to work in the morning.
However, maximizing the benefits of these strategies requires a more coordinated deployment of EVs and solar power. Right now, people aren’t switching to electric vehicles fast enough for their charging needs to use up all the installed solar power. These results “highlight the importance of coordinating the decarbonization of electricity and transport policies,” write the researchers. “Many transportation decarbonization policies lag behind those in the electricity sectors, for example among US states.”
Source: Needell Z. et al. “Beneficial Electric Vehicle Charging Strategies to Reduce Peak Electricity Demand and Store Solar Energy.” Physical Sciences Cell Reports 2023.
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