Electric vehicles (EVs) can have lower fuel costs and reduce emissions relative to cars that use petrol, but they are only a practical option if drivers have convenient ways to charge them. For people who live in multi-unit dwellings or in urban areas, access to charging infrastructure may be particularly limited, which in turn limits EV adoption.

Scalable framework

To address this issue, a team of researchers at Penn State created a scalable framework to develop, analyse and evaluate using street lights as a low-cost, equitable EV charging option.

They then installed 23 street light charging units in Kansas City, Missouri, and tested their framework. The researchers found that street light charging stations, compared to traditional EV charging stations, were more cost- and time-effective, had fewer negative environmental impacts, and were more convenient and accessible. 

A team of Penn State researchers created a scalable framework to develop, analyse, and evaluate using street lights as a low-cost, equitable EV charging option. Image: XB Hu/Penn State.

Their results were published in the Journal of Urban Planning and Development, which is overseen by the American Society of Civil Engineers.

"The motivation for this work comes from the fact that many apartment and multi-unit dwelling residents, particularly in urban and downtown areas, lack access to dedicated home EV chargers, since they don't have the privilege of owning a garage," says Xianbiao 'XB' Hu, associate professor of civil and environmental engineering.

'Well positioned to serve both local residents and visitors'

"Fortunately, street light poles are already powered and typically owned by municipalities, making them relatively easy to work with. Their placement – often near on-street parking and in high-traffic areas – makes them well positioned to serve both local residents and visitors."

Funded by the US Department of Energy, the researchers partnered with the Kansas City, the non-profit organisation Metro Energy Center, local utilities companies and the National Renewable Energy Lab to retrofit existing street lights to function as EV chargers. They then established a three-pronged framework – focused on demand, feasibility and benefits – for other communities to use to develop street light EV chargers.

"The scalability was a huge part of what makes this framework important," says corresponding author Yang 'Chris' Song, who was a doctoral student at Penn State at the time of the research and is now a data scientist at ElectroTempo. "Creating something that works not just in one specific city but that can be adopted by many communities easily is critical for increasing EV use across the country."

To determine demand, the researchers looked at factors including land use, station density, points of interest nearby, and traffic volume and then used the data to train artificial intelligence models to make demand predictions based on these factors.

"We also took into account equity, which here means the proactive engagement with the community to ensure fair and inclusive distribution of the street light charging benefits across diverse neighbourhoods," says Song. 

The researchers used the demand and equity analyses to select 23 street lights and installed EV charging stations. They collected data from the stations for one year.

The infrastructure already existed

Compared to traditional EV charging ports, they found that these stations were much cheaper to install, since the infrastructure already existed.

They also found that the street light chargers offered significantly faster charging speeds, likely because they draw power from dedicated municipal electrical lines and face less competition from multiple vehicles charging simultaneously, unlike clustered commercial stations, according to Yuyan 'Annie' Pan, a postdoctoral researcher working with Hu.

The street light charging stations also benefited the environment, since there were fuel savings and greenhouse gas reductions by using locations where cars were already parking.

"We found that using street lights for EV charging offers an innovative and equitable approach to expanding charging infrastructure and promoting sustainable electrification," says Pan.

For next steps, the researchers say they want to build on their models to incorporate more detailed socioeconomic data and weather information.

Incorporating socioeconomic factors will help identify communities with limited EV access or adoption potential, ensuring more equitable infrastructure deployment. Weather data is also critical, as extreme temperatures can affect battery performance, travel frequency and overall energy demand.