How big is Kleen Energy Systems?

Kleen Energy Systems has a reported capacity of 693 MW. Source: EIA Form 860M.

What kind of plant is Kleen Energy Systems?

Kleen Energy Systems is a Natural Gas Fired Combined Cycle facility in Middlesex County, CT, participating in the ISO-NE market.

Where is Kleen Energy Systems located?

Kleen Energy Systems is in Middlesex County, CT, inside the ISO-NE balancing area.

Who operates Kleen Energy Systems?

Kleen Energy Systems is operated by Kleen Energy Systems, LLC according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

How much electricity does Kleen Energy Systems generate?

Kleen Energy Systems reported 3,583.1 GWh over the twelve months to 2026-04. Figures are net generation as filed to EIA-923.

How does Kleen Energy Systems compare to other plants?

By capacity, Kleen Energy Systems ranks #183 of 538 operating plants of the same technology nationally. It ranks #3 of 11 in CT.

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Kleen Energy Systems

Kleen Energy Systems, LLC - Middlesex County - ISONE

Kleen Energy Systems is a natural-gas-fired combined-cycle power plant located at 1349 River Road, Middletown, Connecticut (Middlesex County). The plant comprises two Siemens SGT6-5000F combustion turbine generators and one Siemens condensing steam turbine generator, with two Vogt heat-recovery steam generators with duct burners. On February 7, 2010, a natural-gas explosion during construction killed six workers and injured many others, causing significant damage. Repairs proceeded, and the facility entered commercial operation in July 2011. The facility is marketed as 620 MW (FERC nameplate capacity totals 693 MW across three units).

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ISO-NE · Asset profile

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Kleen Energy Systems — 693 MW gas plant, CT · Ask the Grid

Overview

Nameplate capacity: 693 MW
Canonical EIA plant baseline.
Registry anchor: Plant 56798
plant-56798

Structured profile

Technology: Natural Gas Fired Combined Cycle
Operator: Kleen Energy Systems, LLC

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Units and generators

Operating generator records and technology attributes reported through EIA-860.

Generator	Capacity	Technology	Operation	Status
ST	295 MW 268 MW summer	Natural Gas Fired Combined Cycle Natural Gas · CA	Jul 2011	Operating
U1	199 MW 177 MW summer	Natural Gas Fired Combined Cycle Natural Gas · CT	Jul 2011	Operating
U2	199 MW 177 MW summer	Natural Gas Fired Combined Cycle Natural Gas · CT	Jul 2011	Operating

Performance

Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.

Peer context

Technology capacity: 693 MW
National rank: #183
CT rank: #3

Monthly generation

Download CSV

Latest 12 months

3.58 TWh

Reported net generation

Latest report

Apr 2026

EIA-923 monthly filing

2025 capacity factor

53.0%

Grid and market context

Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.

Nearby substations

HIFLD infrastructure inventory

KLEEN

IN SERVICE · 345 kV

0.1 km

MIDDLETOWN

Commercial, land, and environmental record

Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.

Transactions and agreements

Commercial Operation

Jul 2011

The Kleen Energy facility entered commercial operation, achieving its required start date within contractual constraints.

Kleen Energy Systems, LLC

kyuden-intl.co.jp

Related parties and identifiers

Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.

Relationship graph

Drag organizations to explore the network. Select a node to pin its details and available page link.

AssetOwner / operatorEquipment

Timeline and sources

Project milestones and public references behind the asset profile.

Project timeline

Jul 2011
Jul 2011
Commercial Operation Beginskyuden-intl...
The Kleen Energy facility entered commercial operation, achieving its required start date within contractual constraints.
May 15, 2018
May 15, 2018
Japanese Investor Entry – Kyushu Electric

Kleen Energy Systems

Ask about Kleen Energy Systems

Kleen Energy Systems

Ask about Kleen Energy Systems

Overview

Structured profile

Related assets

CPV Towantic Energy Center

Milford Power Project

Units and generators

Performance

Peer context

Monthly generation

Grid and market context

Nearby substations

Commercial, land, and environmental record

Transactions and agreements

Related parties and identifiers

Relationship graph

Timeline and sources

Project timeline

Bridgeport Station

Lake Road Generating Plant

Rhode Island State Energy Center

Bridgeport Energy Project

Parties and identifiers

Reporting portfolio

Sources

Common questions about Kleen Energy Systems

How big is Kleen Energy Systems?

What kind of plant is Kleen Energy Systems?

Where is Kleen Energy Systems located?

Who operates Kleen Energy Systems?

How much electricity does Kleen Energy Systems generate?

How does Kleen Energy Systems compare to other plants?

Co-located assets