Introduction

This is National Grid's Third Supplemental Downstate New York Long-Term Capacity Report ("Third Supplemental Report"), the fourth report in a series that began on February 24, 2020, when National Grid ("National Grid" or the "Company") released the Natural Gas Long-Term Capacity Report (the "Original Report") for its service territories in Brooklyn, Queens, Staten Island and Long Island ("Downstate NY") to address forecasted gaps between gas supply and customer demand over a fifteen-year horizon.

The Original Report provided a detailed analysis of the natural gas capacity constraints in the region and the available options for meeting long-term demand. In addition, National Grid held a series of six public meetings and received thousands of written comments on the Original Report and the options.

After reviewing the extensive feedback and public engagement on the Original Report and compiling additional detailed content, National Grid published the Natural Gas Long-Term Capacity Supplemental Report on May 8, 2020 (the "Supplemental Report"). In that report, the Company responded to the public's comments on the Original Report, including on the options presented to address the long-term capacity constraint, and recommended two solutions as the best among all the options presented-an interstate pipeline option or a portfolio of targeted distributed infrastructure and non-gas infrastructure options. Soon thereafter, the state permit applications for the large-scale pipeline project were denied, and National Grid has been executing the other recommended solution-identified in the Supplemental Report as "Option A: LNG Vaporization and Iroquois Gas Transmission System, L.P. ("Iroquois") enhancements to existing infrastructure, combined with incremental energy efficiency (EE) and demand response (DR)." National Grid is focused on implementing this "Option A" solution, which has been augmented since first introduced. This solution now involves an even more aggressive set of incremental demand-side management ("DSM") programs to help customers reduce their natural gas usage, the size of which is unprecedented in New York. The Company is also developing additional portable compressed natural gas ("CNG") capacity and has continued to progress development and seek permits for the proposed LNG vaporization enhancements at its existing Greenpoint facility. The Company is also supportive of the ExC project being pursued by IGTS. Altogether, these programs, projects and additional contracts are collectively referred to as the "Distributed Infrastructure Solution."

National Grid has also made significant corporate commitments that align with New York's ambitious climate change goals as laid out in the Climate Leadership and Community Protection Act ("CLCPA"). In October 2020, National Grid refined its plan to achieve New York's net zero greenhouse gas ("GHG") emissions by 2050 goal ("Net Zero") via its "Net Zero by 2050" plan and updated its Responsible Business Charter to include those ambitions.^[1] Measured against these goals, National Grid believes its Distributed Infrastructure Solution substantially advances CLCPA goals, the Company's Net Zero plan, and a clean energy future.

This Third Supplemental report serves two primary purposes: to offer updates to and respond to stakeholder feedback on the Second Supplemental Report.

The Company is committed to keeping a dialogue open with our customers. The Commission initiated the Proceeding to Improve Transparency of Natural Gas Planning and Investments in New York (Case No. 20-G-0131) in March 2020 after the Company had prepared and filed its Original Report. The various gas utilities and stakeholder groups in NY, along with DPS Staff, have been filing comments and proposals for review by the Commission on topics such as gas constraints, gas planning, non-pipe solutions, gas moratoria standards, and demand-side resources. While there is much work to be done and decisions to be made in the proceeding, the Commission and New York's gas utilities will ensure stakeholders have a seat at the table as we make important decisions together about the future of our gas business and our customers' energy needs. National Grid looks forward to working with customers and other stakeholders to fully realize the clean energy transition.

In addition to filing the Third Supplemental Report with the New York Public Service Commission, we will be publishing this report on our website and will deploy other options for sharing the report with stakeholders, including a reader friendly summary and web content.