Briefing on Tunnel

Tunnel, a 21 MW hydroelectric plant operating since 1919, is undergoing a significant upgrade with the Fishheart Fish Passage System, despite recent generation being near zero.

Overview

• Plant Name: Tunnel

• Location: Connecticut

• Status: Operating since 1919

• Operator: FirstLight Power Resources Services LLC (EIA operator)

• Owner: FirstLight Hydro Generating Company

• Project Name: Fishheart Fish Passage System at Tunnel Hydropower Plant (International Water Power, 2025-05-13)

• Developer: FirstLight Power (International Water Power, 2025-05-13)

• EPC Contractor: Fishheart Ltd. (International Water Power, 2025-05-13)

• Latest Milestone: Project start in 2024 (International Water Power, 2025-05-13)

• Expected COD: Q4 2024 (Energy-Storage.News, 2022-10-13)

Fleet Details

• Capacity: 21 MW

• Technology: Conventional Hydroelectric, Petroleum Liquids

• Generators: 3 units

• Grid Connections: ISO New England (ISO), NPCC (NERC), ISO New England Inc. (BA)

Generation & Performance

• Annual Generation: 8 GWh

• Capacity Factor: 4.3%

• Recent Generation (2024-10 to 2024-12): 0 GWh each month

• Generation Trend: Down 94% over the past 6 months compared to the prior 6 months

Financial Profile

• Capital Expenditure: $2294/kW (Source: eia_agg_cost)

Tunnel is an aging hydroelectric plant undergoing significant updates, including a new fish passage system and an expected commercial operation date in Q4 2024. Despite its long operational history, recent generation has been minimal, indicating a period of low output or potential refurbishment activities.