Gemma Power Systems
Gemma Power Systems is a U.S.-based EPC contractor founded in 1997, specializing in utility-scale power generation and renewable energy facility construction. A wholly owned subsidiary of Argan, Inc. (NYSE: AGX), it serves independent power producers, utilities, and energy developers across the U.S. and recently expanded into Ireland and the UK.
- Company typePrivate
- Founded1997
- HeadquartersGlastonbury, United States
- Headcount501–1,000
- GTM typeB2B
- OfferingServices
What Gemma Power Systems does
Gemma Power Systems is a U.S.-based Engineering, Procurement and Construction (EPC) contractor specializing in utility-scale power generation and renewable energy facilities. Founded in 1997 and headquartered in Glastonbury, Connecticut, the company delivers combined cycle, simple cycle, solar, wind, and biomass projects for independent power producers, utilities, energy developers, and cooperatives. Gemma operates a renewable energy division (Gemma Renewable Power, formed 2008) and an Operations & Maintenance (O&M) business unit, and is the largest subsidiary of Argan, Inc. (NYSE: AGX), which acquired it in 2006.
The company does not develop proprietary turbine technology. Its technical value-add is construction execution, project management, constructability review, and integration of OEM-supplied equipment from Siemens Energy, GE Vernova, Mitsubishi Power, and ABB. Quality management is grounded in ASME and ISO 9000 standards, and Gemma has consistently delivered OSHA recordable incident rates well below the industry average (0.28 in 2024 versus 1.6 industry average). Design engineering is typically performed by partners including Sargent & Lundy, POWER Engineers, Stantec, and Mott MacDonald, while Gemma self-performs much of the construction labor alongside local subcontractors.
Gemma's business model is anchored in individually negotiated fixed-price EPC contracts, supplemented by recurring O&M revenue on assets it has built. Pricing is not publicly disclosed; contract values are typically hundreds of millions to over a billion dollars per project (Trumbull $1.2B, CPV Basin Ranch $1.88B total project cost, Guernsey $1.6B investment, Sandow Lakes 1.2 GW). Go-to-market is direct enterprise sales with senior leadership personally engaged in IPP/utility negotiations. The company carries a project backlog of approximately $2.8 billion as reported by Argan, Inc. in Q1 FY2027, and in 2025 expanded internationally by assuming operational responsibility for sister company Atlantic Projects Company, extending its footprint into Ireland and the UK.
Gemma Power Systems firmographics
Firmographics- Name
- Gemma Power Systems
- Legal name
- Gemma Power Systems, LLC
- Website
- https://gemmapower.com
- Company type
- Private
- Founded year
- 1997
- Operating status
- Operating
- Headcount range
- 501–1,000 employees
- Short description
- Gemma Power Systems is a U.S.-based EPC contractor founded in 1997, specializing in utility-scale power generation and renewable energy facility construction. A wholly owned subsidiary of Argan, Inc. (NYSE: AGX), it serves independent power producers, utilities, and energy developers across the U.S. and recently expanded into Ireland and the UK.
- Ownership category
- akta.pro rank
Gemma Power Systems industry classification
Industry- Product category
- Power Plant Construction and Engineering Services
- NAICS
- Electric Power Generation (22111), Electric Power Generation, Transmission and Distribution (2211)
- SIC
- Electric, Gas & Sanitary Services (4900)
- akta.pro primary industry
- Thermal Power Plant EPC (Gas/Coal/Oil) (EUAEAAAA)
- akta.pro secondary industries
- Solar PV Power Plant EPC (Utility-Scale) (EUAEAAAG), Wind Power Plant EPC (Onshore/Offshore) (EUAEAAAF), Power Plant I&C / SCADA / DCS EPC (EUAEAAAN), Electrical Balance-of-Plant EPC (MV Collection, Cabling, Earthing, Lighting) (EUAEADAB)
Keywords
Where Gemma Power Systems is headquartered
LocationHeadquarters
- HQ city
- Glastonbury
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
Gemma Power Systems business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Operations, Supply Chain, Infrastructure, Technology or R&D
Revenue model
- EPC Contract Revenue: Gemma Power Systems generates the majority of its revenue through fixed-price Engineering, Procurement, and Construction (EPC) contracts for power generation facilities. These contracts cover the full project lifecycle from engineering and procurement through construction and commissioning. Revenue is recognized over the construction period as projects are executed.
- Operations & Maintenance Services: Gemma provides ongoing Operations and Maintenance (O&M) services for power generation facilities including routine inspections, preventive and predictive maintenance, system diagnostics, and rapid troubleshooting to maximize uptime and performance. This represents a recurring revenue stream built on existing project relationships.
Go-to-market motion1 record
Distribution channels1 record
Marketing channels6 records
Gemma Power Systems product offering
Product offeringCore offering
Gemma Power Systems is an Engineering, Procurement and Construction (EPC) contractor that delivers utility-scale power generation and renewable energy facilities, including combined cycle and simple cycle natural gas plants, solar, wind, and biomass projects. The company also offers Operations and Maintenance services, Development Assistance for early-stage projects, and Safety and Quality services grounded in ASME and ISO 9000 principles. Customers are independent power producers, utilities, and energy developers who contract Gemma to execute large-scale energy infrastructure projects on a fixed-price basis.
Product overview
Gemma Power Systems is a specialized power generation EPC firm that operates as a single unified service provider rather than a platform-plus-modules architecture. The company offers four core service lines: Engineering, Procurement, and Construction (EPC); Operations & Maintenance (O&M); Development Assistance; and Safety & Quality Services. These services are applied across diverse power generation project types including Combined Cycle natural gas-fired plants (e.g., Trumbull Energy Center, Guernsey Power Station), Simple Cycle peaking plants, Solar facilities (Maple Hill Solar), Wind farms (Grand Ridge, Bishop Hill), Biomass plants (Hilton Lively), and renewable fuel production (ethanol, biodiesel). The portfolio spans over 40 projects nationwide, and Gemma functions as a wholly-owned subsidiary of Argan, Inc. (NYSE: AGX).
Differentiator
Problem solved
Functional benefit
Products and services
- EPC (Engineering, Procurement, and Construction)
Quantifiable outcome
- OSHA recordable incident rate of 0.28 in 2024 vs. industry average of 1.6
- +4 more outcomes
Companies that use Gemma Power Systems
Customer profileNamed customers15 records
Segments2 records
Ideal customer profiles3 records
Gemma Power Systems technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature2 records
Gemma Power Systems partnerships and signals
Strategic signalPartnerships
13 partnerships are on record, tiered core.
- Korea Southern Power Co. Ltd. (KOSPO)coreKOSPO is a joint owner of the Trumbull Energy Center alongside KIND and Siemens Energy. As a Korean state-owned power company, KOSPO brought international investment and partnership to the $1.2 billion project. Gemma served as the EPC contractor for this facility.
- Korea Overseas Infrastructure and Urban Development Corp. (KIND)coreKIND is a Korean government-owned institution that invests in overseas infrastructure projects. Together with KOSPO and Siemens Energy, KIND is a joint owner of the Trumbull Energy Center. Gemma served as the EPC contractor.
- Siemens EnergycoreSiemens Energy is a joint owner of the Trumbull Energy Center and serves as the turbine supplier (SGT6-8000H gas turbines) and technology partner. Gemma has a long-standing relationship with Siemens Energy across multiple projects, including the Trumbull Energy Center where Siemens Energy is both a technology partner and co-investor.
- GE VernovacoreGE Vernova supplies turbines for Gemma-executed projects including the CPV Basin Ranch Energy Center (GE 7HA.03 turbines) and the Guernsey Power Station (GE 7HA.02 turbines). GE Vernova is listed as a key partner on Gemma's homepage. Gemma serves as the EPC contractor on projects where GE Vernova equipment is specified.
- Atlantic Projects Company (APC)coreAPC is a sister company under Argan, Inc. and Gemma officially assumed full operational responsibility for APC in 2025, integrating APC's international footprint (Ireland and UK) with Gemma's U.S. power project expertise. Gemma collaborated with APC on the 264 MW Shannonbridge Power Project in County Offaly, Ireland.
- Sargent & LundycoreSargent & Lundy serves as the design engineer for multiple Gemma projects including Trumbull Energy Center, NTE Middletown Energy Center, and NTE Kings Mountain Energy Center. Gemma partners with Sargent & Lundy for detailed engineering design on power plant projects.
- Mitsubishi PowercoreMitsubishi Power (Mitsubishi Hitachi Power Systems Americas) supplies combustion turbine generators for Gemma projects including NTE Middletown Energy Center (M501GAC CTG) and NTE Kings Mountain Energy Center (M501GAC CTG). Listed as a key partner on Gemma's homepage.
- POWER EngineerscorePOWER Engineers serves as design engineer for multiple Gemma projects including Panda Liberty Power Project and Caithness Freedom Generating Plant. Listed as a key partner on Gemma's homepage.
- StanteccoreStantec serves as the design engineer for the CPV Maple Hill Solar project. Listed as a key partner on Gemma's homepage.
- Mott MacDonaldcoreMott MacDonald serves as design engineer for the Patton Wind Farm and Sentinel Energy Project. Listed as a key partner on Gemma's homepage.
- Caithness EnergycoreCaithness Energy is a repeat customer and long-term partner of Gemma. Gemma has served as EPC contractor for Guernsey Power Station (1,875 MW, $1.6B investment) and Caithness Freedom Generating Plant (1,040 MW). Caithness Energy is listed as a key client on Gemma's homepage.
- Clean Energy Future - Trumbull (CEF Trumbull)coreClean Energy Future-Trumbull is the developer of the Trumbull Energy Center. Gemma received full notice to proceed from CEF Trumbull in November 2022 for the 950 MW combined cycle project. CEF Trumbull is listed as the customer on Gemma's project profile for the Trumbull Energy Center.
- Competitive Power Ventures (CPV) Basin Ranch HoldingscoreCPV Basin Ranch Holdings LLC is the developer of the CPV Basin Ranch Energy Center, a 1,350 MW combined-cycle natural gas power plant in Ward County, Texas, with total project costs of $1.88 billion. Gemma received full notice to proceed in December 2025. The project is financed in part by a $1.1 billion Texas Energy Fund loan.
Scale indicators10 records
Recent moves9 records
Expansion highlights5 records
Gemma Power Systems competitors and assessment
Company assessmentDirect peers
- Burns & McDonnell: Employee-owned engineering, construction, and consulting firm with a strong power generation EPC practice serving utilities and IPPs in the U.S. Directly competes with Gemma on combined cycle, simple cycle, and renewable energy projects.
- Mortenson Construction: Major U.S. contractor with significant wind, solar, and energy storage EPC capabilities. Direct peer to Gemma Renewable Power in renewable energy construction, with overlapping customer base of IPPs and developers.
- McCarthy Building Companies: Large employee-owned U.S. builder with a dedicated Renewable Energy and Power group. Directly competes with Gemma on utility-scale solar, wind, and combined cycle projects for IPPs and utilities.
- Zachry Group: Privately held construction and engineering firm with a long history in power plant EPC, including combined cycle facilities. Closely comparable to Gemma in size, focus, and customer base among U.S. utility-scale power developers.
- Atlantic Projects Company (APC): Sister company under Argan, Inc. specializing in power plant construction in Ireland and the UK. Closely related peer as Gemma assumed full operational responsibility for APC in 2025, integrating international power EPC capabilities.
Broad incumbents
- Quanta Services: Publicly traded (NYSE: PWR) infrastructure construction leader with electric power, renewable energy, and energy storage capabilities. Comparable to Gemma in power and renewable EPC but operates at a much larger scale across transmission, distribution, and oil & gas.
- Fluor Corporation: Major global EPC firm with a dedicated power group historically led by Gemma SVP Bob Haupt. Competes with Gemma on utility-scale power projects while also serving mining, infrastructure, and government clients. Publicly traded (NYSE: FLR).
- Kiewit Corporation: Large privately held North American construction firm with significant power plant construction capabilities, including combined cycle and renewable projects. Direct competitor for utility-scale power EPC contracts.
- Bechtel Corporation: One of the largest global EPC contractors with significant power generation and renewable energy practice. Directly comparable to Gemma as a power plant EPC competitor but operates at a much larger scale across multiple end markets including infrastructure, nuclear, and defense.
- MasTec, Inc. Publicly traded (NYSE: MTZ) infrastructure construction firm with significant power delivery and clean energy capabilities. Competes with Gemma in power and renewable EPC but is more diversified across communications, pipeline, and oil & gas infrastructure.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks6 records
Key highlights7 records
Customer concentration
Gemma Power Systems social profiles
Digital presenceGemma Power Systems financial estimates
Financial estimateRevenue estimate
Valuation estimate
Gemma Power Systems leadership team
Management profileNumber of profiles
Profiles20 records
Gemma Power Systems subsidiaries and ownership
Company hierarchySubsidiaries1 record
Gemma Power Systems funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Gemma Power Systems M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Gemma Power Systems
What does Gemma Power Systems do?
Gemma Power Systems is an Engineering, Procurement and Construction (EPC) contractor that delivers utility-scale power generation and renewable energy facilities, including combined cycle and simple cycle natural gas plants, solar, wind, and biomass projects. The company also offers Operations and Maintenance services, Development Assistance for early-stage projects, and Safety and Quality services grounded in ASME and ISO 9000 principles. Customers are independent power producers, utilities, and energy developers who contract Gemma to execute large-scale energy infrastructure projects on a fixed-price basis.
Is Gemma Power Systems a public or private company?
Gemma Power Systems is a private company. It is classified as corporate owned and is currently operating.
When was Gemma Power Systems founded?
Gemma Power Systems was founded in 1997. It employs 501 to 1,000 people.
Where is Gemma Power Systems based?
Gemma Power Systems is headquartered in Glastonbury, United States, in the North America region.
How does Gemma Power Systems make money?
Two revenue lines are on record. EPC Contract Revenue is the primary driver. The others are operations & Maintenance Services.
Who are Gemma Power Systems's main competitors?
Direct peers on record are Burns & McDonnell, Mortenson Construction, McCarthy Building Companies, Zachry Group and Atlantic Projects Company (APC). Broad incumbents are Quanta Services, Fluor Corporation, Kiewit Corporation, Bechtel Corporation and MasTec, Inc..
Does Gemma Power Systems have an API?
No public API is recorded for Gemma Power Systems.
What industry is Gemma Power Systems in?
Gemma Power Systems's product category is Power Plant Construction and Engineering Services. Its primary akta.pro industry code is EUAEAAAA, Thermal Power Plant EPC (Gas/Coal/Oil), with a secondary code of EUAEAAAG, Solar PV Power Plant EPC (Utility-Scale). Its NAICS code is 22111 and its SIC code is 4900.