Locating EV Charging Stations in Somerville
Somerville Office of Sustainability & Environment
Background Information
- In 2023, the Mayor’s Office of Sustainability and Environment of the City of Somerville commissioned the Somerville Public Electric Vehicle Supply Equipment (EVSE) Siting Strategy Report to develop a thoughtful approach to siting EV charging stations in the coming years.
- Climate Forward, the City's climate action plan, calls for the electrification of 40% of passenger vehicles by 2030, 90% by 2040, and 100% by 2050 to help in our primary goal of being carbon net-negative by 2050.
- Currently, the City owns and operates 12 publicly accessible EV charging stations, shown in the map to the right.
Community Scores and Commercial Scores
Over 30 locations across the City of Somerville were investigated for a buildout of the City's charging infrastructure. The City developed two tools, called our Community & Commercial Scores, to help evaluate locations and guide decision-making.
- The Community Score represents areas that should be prioritized to promote equitable EV station access for underserved communities and those who may be less able to install private chargers.
- The Commercial Score represents areas that should be prioritized to promote economic activity in key commercial areas and facilitate charging in non-residential locations while Somerville residents visit destinations like grocery stores, restaurants, and other amenities.
Evaluation of Community and Commercial Scores
Community and Commercial Scores were evaluated at the Census Block Group level, and are made up of five criteria. Those criteria include:
Massachusetts Environmental Justice Communities
This criterion was selected to ensure the siting process prioritizes equitable distribution of capital investment in EV stations; additionally, EJ is a consideration for the Eversource Public & Workplace EV Charging Program which provides rebates for EV stations and their installation. Criteria was scored as a binary 1 (yes) / 0 (no) for each Census Block Group.
Number of Publicly-accessible EV Chargers, both publicly and privately owned
This criterion considered the number of public and privately owned, publicly accessible chargers within 0.25-mile radius of each Census Block Group. City chargers were weighted 1 and chargers owned by other entities (private companies and neighboring municipalities) were weighted at 0.75 as their pricing and accessibility may not always meet the City’s preferences. Criteria was scored on quintiles of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 for each Census Block Group, with a higher score representing fewer chargers (and therefore greater need for EV stations).
Proximity to a T Station
This criterion evaluated whether each Census Block Group is within a 10-minute walk to a T station. It was selected because the City wishes to prioritize public transit usage above private EV ownership and does not wish to provide incentives for public transit riders to purchase a personal vehicle even if it is electric. Criteria was scored as a binary 1 (no T access) / 0 (has T access) for each Census Block Group.
Current EV Ownership
This criterion was selected to provide EV station access for those who already own EVs, with the assumption that further adoption will follow current purchasing patterns across the city. Passenger EVs were weighted as 1, while plug-in hybrids were weighted 0.25 due to their relatively lower battery capacity. Criteria was scored on quintiles of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 for each Census Block Group, with a higher score representing greater EV ownership.
Multifamily housing (Community Score only)
Multifamily housing as a percentage of land area was considered for the community score, with the goal of prioritizing locations with a greater portion of renters and therefore relatively less access to private charging. Criteria was scored on quintiles of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 for each Census Block Group, with a higher score representing a greater proportion of multifamily development. Commercial overlay district (Commercial Score only): Commercial overlay districts represent areas where the City wishes to encourage additional economic activity, including new commercial areas as well as small businesses. Criteria was scored as a binary 1 (commercial overlay) / 0 (no commercial overlay) for each Census Block Group.
Candidate Site Selection
- Each potential EV site was evaluated across a range of factors, including their Community and Commercial Scores, available electrical capacity, and ease of installation.
- Of the 33 sites evaluated, 5 were excluded due to proximity to a floodplain.
- Two of the existing sites, Day Street and Union Square, were not evaluated for additional charging infrastructure due to the weekly farmers market regularly interfering with parking at those locations.
- The remaining candidate sites are shown in the map to the right.
Site prioritization
- The remaining 26 sites were evaluated as potential locations for EV stations.
- Eight sites were identified as being highest priority and were selected for in-depth analysis and cost estimation. These are stations that the Office of Sustainability & Environment is working on now to install.
- The remaining sites were classified as medium-term, long-term, or not recommended.
Highest Priority Sites
- Ibbetson Street: Highest marks on all Scores, high ease of electrical installation, and a net-new site.
- Veterans Memorial Hockey Rink: Highest marks on all Scores, high utilization of the existing City-owned (53%), opportunity to expand access at a site that existing users are familiar with.
- Foss Park Lot: Highest marks on Community Score, high ease of electrical installation, and opportunity to install multiple chargers at a new site including ADA accessible EV station.
Near-term Sites
- Teele Square and Lombardi Street: Good marks on Community Score, good utilization of the existing City-owned site, opportunity to expand access at a site that existing users are familiar with.
- Josephine Ave (Ball Square): New site with high ease of electrical installation and an opportunity to site ADA-accessible EV station.
- Munroe Street: Good marks across all Scores and medium ease of installation.
Medium-term Sites
- Existing EV sites with high or medium ease of electrical installation to expand charger access at sites that drivers are accustomed to using.
Long-term Sites
- New and existing sites with lower ease of electrical installation.
- Some sites with high combined scores, such as Kimball Street and Victoria Street, could be considered for installation sooner especially if there is nearby capital work that EV station installation could be tied into.
Sites Not Recommended
- Locations in floodplain deeper than 6 inches or significant complications with electrical installation
