Eversource_Somerville_Council_Electrification_Slides_Nov 2024 — File 24-1552

Somerville City Council Update 1

o Introductions o Massachusetts’ Clean Energy Goals o Electric Sector Modernization Plan (ESMP) o Demand Growth o Projects Underway and Planned o Outreach and Stakeholder Engagement o Q&A Agenda

Massachusetts’ Clean Energy Goals 33% Reduction by 2025 50% Reduction by 2030 75% Reduction by 2040 NET ZERO EMISSIONS by 2050 MA LAW REQUIRES REDUCING GREENHOUSE GAS EMISSIONS 2022 Climate Bill requires each Electric Distribution Company develop an Electric- Sector Modernization Plan (ESMP) to proactively upgrade the distribution and, where applicable, transmission systems to meet the Commonwealth’s climate goals MA LAW REQUIRES DEVELOPMENT OF ELECTIC SECTOR MODERNIZATION PLAN

Home of the Clean Energy Future

Solving for Increased Electric Demand • Infrastructure Needed Requires an electric network buildout and upgrades at an unprecedented pace and scale, in collaboration with customers, communities, policymakers, and other stakeholders. • Meaningful Engagement Those potentially impacted by this transition deserve to play a role in energy discussions that affect their lives UPGRADES AHEAD Yesterday’s Grid Tomorrow’s Grid WHERE WE ARE WHERE WE ARE HEADING

Key Drivers of the Net-Zero Goals Zero-carbon heating projected to add 3.5 GW of winter demand by 2035 Electric vehicle adoption projected to add 1.3 GW of winter demand by 2035 0 2 4 6 8 10 12 14 16 18 Current Base Load 2028 2033 2035 2040 2045 2050 Gigawatts (GW) Enabled by 10-year Plan  Residential  Commercial/ Industrial  Transportation  Heating What is a Gigawatt? It’s the equivalent of 100 million LED bulbs! Source: energy.gov Eversource Peak Electric Demand System shifts from summer peaking to winter peaking

7 Location of Major Capital Projects in the 10-Year Plan Metro West 4 new stations 4 station upgrades Southern 4 new stations 7 station upgrades Western 2 new stations 11 station upgrades Investments in 17 new clean energy hubs and upgrades to 26 over the next ten years will enable the clean energy future in Massachusetts Metro Boston 7 new stations 4 station upgrades

• The Company is closely monitoring development in Somerville • New Office blocks and life science building development at Assembly, Boynton Yards, and Union Square make up 81% of 60MW of new load in Somerville city proper What’s driving the near-term demand growth in Somerville? 8 81%, 49 16%, 10 2%, 1 2%, 1 0 10 20 30 40 50 60 Office/Life Science Lab Residential/Retail Other Transportation Load (MW) Large Customer Categories for Step Loads to 2030

10 Year Capacity Deficiencies in The City of Somerville translate to negative reliability outcomes if not immediately addressed 9 Substation Name Boston Communities Served 2030 Substation Loading % Ten-Year Project Solution And Need Date Mystic Charlestown, City of Somerville 99 2022. Somerville Substation Expansion (Delayed as of September 2024) 2032. New Charlestown/Somerville Substation Mystic City of Somerville • New Charlestown/Somerville Substation provides long-term capacity relief for neighborhood of Charlestown and City of Somerville Legend: Area near capacity Area at Capacity Potential New Substation Area Area directly benefiting from New Substations New Charlestown/Somerville Substation (2032) 9 Somerville Substation Expansion (2024) Union Square Planning | City of Somerville (somervillema.gov)

Prospect Street Substation #402 (Somerville) and Distribution Work (Somerville & Cambridge) Underway – Construction ongoing for addition of a third transformer at the existing Prospect Street Substation in Somerville. This project also includes about 2.5 miles of new distribution duct bank, including portions in Somerville and Cambridge. Greater Cambridge Energy Program, Substation #8025 Underway - Executive Facilities Siting Board approval of new underground substation, five underground transmission routes through city streets to existing substations in Boston, Cambridge, and Somerville. New Projects in Planning Phase Planning – Underground Cable Modernization Program (UCMP) aims to replace high pressure fluid filled (HPFF) cable with new duct bank and cross-linked polyethylene (XLPE) cable between Mystic and Prospect Street substation and Mystic to North Cambridge substation. Planning - Fence and Control House Upgrades Electric System Projects Currently Underway and Planned for Somerville 10

Community Relations Jason Wright Mobile: [phone removed] Email: [email removed] 11