What Stemac does

Stemac S/A Grupos Geradores is a Brazilian manufacturer of power generation equipment founded in 1951 and headquartered in Porto Alegre, Rio Grande do Sul. The company designs, manufactures, and services diesel generator sets, natural gas generator sets, compact mini-generators (MINIGEN PRO, 25–32 kVA), high-capacity units (DUOGEN, 1000–1400 kVA), control and power panels, and the POWERBOX Battery Energy Storage System (BESS) developed in partnership with WEG. Core manufacturing is concentrated at a 1 million m² facility in Itumbiara, Goiás, with 62,000 m² of built area and capacity of up to 1,500 generator sets per month. The company operates 50 service locations across all 24 Brazilian states, providing nationwide technical service and parts distribution.

The business model combines one-time equipment sales (generators, panels, spare parts) with recurring planned-maintenance subscriptions and specialized technical services. Distribution occurs through a multi-channel mix: enterprise field sales for large projects, inside sales via phone and WhatsApp, an e-commerce store (loja.stemac.com.br) carrying 2,000+ parts, and export operations serving international markets. Customer segments span industrial and commercial enterprises, agribusiness, construction and infrastructure, independent service technicians, and export markets. The company holds ISO 9001 certification (achieved in 1998 as the first Brazilian generator manufacturer) and uses a proprietary Testing Management System (SGT) based on ISO 8528 for quality control.

The corporate structure places operating subsidiaries STEMAC S/A Grupos Geradores and STEMAC Energia S/A under a parent holding, STEMAC S/A Participações. The company is currently operating under judicial recovery (recuperação judicial), with creditor documents published across Classes I–IV — a material consideration for credit and counterparty risk assessment. Despite this, Stemac maintains an installed base and brand recognition that places it among the top 10 generator set manufacturers globally.

Name

Stemac

Legal name

STEMAC S/A Grupos Geradores

Website

https://stemac.com.br

Company type

Private

Founded year

1951

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

Stemac is a Brazilian generator set manufacturer founded in 1951, producing diesel, gas, and battery energy storage systems for industrial, commercial, agribusiness, and infrastructure customers, with 50 service operations across all 24 Brazilian states and export operations internationally.

Ownership category

akta.pro rank

Product category

Power Generation Equipment

NAICS

Turbine and Turbine Generator Set Units Manufacturing (333611), Motor and Generator Manufacturing (335312), Engine, Turbine, and Power Transmission Equipment Manufacturing (33361)

SIC

Motors & Generators (3621), Engines & Turbines (3510), General Industrial Machinery & Equipment (3560)

akta.pro primary industry

Reciprocating Engine Generator Sets (Diesel/Gas/HFO) (IMAHAFAC)

akta.pro secondary industries

Power Generation Plant Construction (Thermal, Hydro, Nuclear) (IMAFADAC), Emergency Generator & Transfer Switch Troubleshooting (HSAOAEAI), Utility-Scale BESS Project Development & Ownership (IPP/Developer) (EUAFAAAA), Energy Storage Components for Renewables Manufacturing (BESS Packs, PCS, Thermal Management) (EUAMAHAI)

Keywords

• Diesel generator sets
• Power generation equipment
• Battery energy storage
• Generator maintenance services
• Power control panels

Headquarters

HQ city

Porto Alegre

HQ country

Brazil

HQ region

Latin America

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Personnel, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Generator Sales: Sale of diesel, gas, and battery energy storage generator sets. Products include MINIGEN PRO, DUOGEN, POWERBOX BESS, and custom generator solutions for various power requirements.
2. Parts and Components Sales: Online store selling over 2000 parts for generator maintenance including electrical/electronic components, mechanical parts, and revision kits for multiple engine brands (Baudouin, Cummins, MWM, Scania, Volvo, Mitsubishi, MTU, Mercedes Benz, Hyundai, FPT, Perkins).
3. Technical Services: Post-sale services including programmed maintenance plans, specialized services, and technical assistance. Services include scheduled visits and emergency visit quotas adapted to customer needs.
4. Planned Maintenance: Programmed revision plans providing complete equipment verification with scheduled visits and emergency visit quotas. Performed by specialized technicians trained by STEMAC.
5. Export Operations: International sales and export of generator sets to foreign markets.

Pricing tiers

Go-to-market motion3 records

Distribution channels5 records

Marketing channels6 records

Core offering

Stemac manufactures and supplies diesel, gas, and battery energy storage (BESS) generator sets along with control and power panels, spare parts for multiple engine brands, and scheduled maintenance and technical assistance services. The company operates a 1 million m² manufacturing facility in Itumbiara, Goiás capable of producing up to 1,500 generator sets per month, supported by a service network of 50 operations across 24 Brazilian states and an online store selling more than 2,000 parts.

Product overview

Stemac offers a comprehensive portfolio of power generation solutions centered around generator sets (grupos geradores) operating on diesel and gas fuels. The core product line includes diesel generators, gas generators, the POWERBOX Battery Energy Storage System (BESS) developed with WEG, compact MINIGEN PRO units (25-32 kVA), and high-capacity DUOGEN units (1000-1400 kVA). Supporting the generator products are control and power panels, remote supervision services, and an extensive spare parts ecosystem covering electrical/electronic and mechanical components for multiple engine brands. The company also provides scheduled maintenance programs and specialized technical services. This integrated approach delivers complete lifecycle support from equipment project and manufacturing through installation, services, and spare parts.

Differentiator

Problem solved

Functional benefit

Brands

• STEMAC S/A Participações: Parent holding company structure containing STEMAC S/A Grupos Geradores and STEMAC Energia S/A operating entities.
• STEMAC Energia
• Loja Online Stemac

Products and services

• Diesel Generator Sets (Geradores a Diesel) Diesel-powered generator sets for backup and primary power generation, available in various capacities, for industrial, commercial, data center, hospital, and agribusiness customers.
• MINIGEN PRO Compact generator line available in 25 and 32 kVA models for smaller-scale power needs.
• MINIGEN PRO GARDEN Compact 25 and 32 kVA generator variants designed for garden and outdoor applications.
• DUOGEN 1000 and 1400 kVA High-capacity generator models with 1000 and 1400 kVA power ratings for large-scale and demanding power requirements.
• Gas Generator Sets (Geradores a Gás) Natural gas-powered generator sets for cleaner primary or backup energy generation.
• POWERBOX BESS Battery Energy Storage System (BESS) developed in partnership with WEG, providing backup energy solutions with integrated power storage capability.
• Control and Power Panels (Painéis de Controle e Força) Control and power panels for generator set management and electrical distribution, sold as standalone equipment.
• Electrical and Electronic Spare Parts Online-store offering of electrical and electronic spare parts including alternators, batteries, circuit breakers, connectors, controllers, sensors, and transformers for generator maintenance.
• Mechanical Spare Parts Online-store offering of mechanical spare parts including filters, pumps, gaskets, belts, radiators, turbochargers, and engine components.
• Mechanical Revision Kits (Kits Revisão Mecânica) Pre-packaged mechanical revision and maintenance kits for generator engines, covering brands including Baudouin, Cummins, MWM, Scania, Volvo, Mitsubishi, MTU, Mercedes Benz, Hyundai, FPT, and Perkins.
• Scheduled Maintenance Program (Revisão Programada) Recurring subscription-based scheduled inspection and maintenance service for generator sets, with customized plans adapted to client equipment and needs, including scheduled visits and emergency visit quotas.
• Specialized Technical Services (Serviços Especializados) Specialized on-site and workshop repair services covering Stemac and other manufacturer generator sets.

Quantifiable outcome

• Up to 80% reduction in GHG emissions with compliant motors meeting international emission standards
• +3 more outcomes

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Two partnerships are on record, tiered core and supporting.

• WEGcoreTechnology or IntegrationStrategic technology partnership for POWERBOX BESS (Battery Energy Storage System) product line. The POWERBOX is branded as 'the BESS from STEMAC by WEG', indicating deep technology collaboration on battery energy storage solutions for backup power applications.
• Bureau Veritas Certification (BVC)supportingOthersPrimary certification body in Brazil conducting systematic audits to ensure ISO 9001 certification and maintain rigorous quality management principles.

Scale indicators6 records

Recent moves3 records

Expansion highlights5 records

Direct peers

• Himoinsa: Spanish manufacturer of generator sets and energy storage systems with strong Latin American distribution, now part of the Yanmar group. Direct competitor in the regional genset market Stemac serves and a more direct peer than the U.S. giants on mid-range kVA industrial standby applications.
• Aggreko: U.K.-based specialist in temporary power and temperature-control solutions, with growing BESS rentals. Comparable on rental/lease business models and on serving construction, industrial, and event end-markets with mobile generator sets, an adjacency Stemac touches via construction-sector sales.
• Kohler Power Systems: U.S.-based manufacturer of industrial and residential generator sets and paralleling-switchgear. Comparable product portfolio across diesel, gas, and increasingly BESS-enabled standby power, with similar go-to-market emphasis on engineered-to-order solutions and OEM partnerships.
• Generac: U.S.-based global leader in power generation equipment including diesel, gas, and increasingly BESS/residential storage solutions. Closely mirrors Stemac's product mix of standby and prime gensets, with similar diversification into residential and industrial power, though at significantly larger global scale.
• MTU/Rolls-Royce Power Systems: German manufacturer (Rolls-Royce subsidiary) of high-speed engines and diesel/gas generator sets up to multi-megawatt capacity, including mission-critical data-center and infrastructure standby power. Comparable to Stemac's DUOGEN line and competitive on the same large-kVA infrastructure tenders in Brazil.

Broad incumbents

• Cummins: U.S.-based global manufacturer of diesel and natural gas engines and generator sets with a broad portfolio across power generation, industrial, and rail. Directly comparable to Stemac's core diesel/gas genset business and is also one of the engine brands whose parts Stemac distributes and services in Brazil.
• Caterpillar (CAT Electric Power): Global heavy-equipment OEM whose Electric Power division sells generator sets, switchgear, and integrated power solutions. Comparable to Stemac on large-kVA gensets (e.g., DUOGEN 1000/1400 kVA tier) and on the end-to-end project/aftermarket service model Stemac competes with in Brazil.
• Atlas Copco (Power & Flow division): Swedish industrial group with a Power & Flow division producing mobile generators, BESS, and energy storage solutions. Direct overlap with both Stemac's traditional genset line and its POWERBOX BESS offering; competes for the same mining, oil & gas, and construction site power customers in Latin America.

Others

• WEG: Brazilian electrical equipment and motor manufacturer that is Stemac's strategic technology partner for the POWERBOX BESS ('the BESS from STEMAC by WEG'). Also independently manufactures generators, motors, and energy storage systems, making WEG both a supplier/partner and a partial competitive overlap.

Regional players

• Tognum / Rolls-Royce Solutions: German manufacturer of large diesel and gas engines for power generation and propulsion, serving Latin American infrastructure and oil & gas markets primarily through regional distributors. Comparable on multi-megawatt genset engineering but typically delivers into Brazil through partners rather than a local OEM footprint like Stemac's.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xx.com/StemacOficial
• Facebookfacebook.com/stemacgruposgeradores
• LinkedInlinkedin.com/company/stemac

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Subsidiaries2 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Stemac