Largest Renewable Energy Engineering Companies 2026

The global energy transition is accelerating. In 2025 alone, renewable power additions hit 580 GW, pushing total installed capacity past 4,800 GW by early 2026, according to IEA data. Behind every wind farm, solar park, and battery energy storage system (BESS) stands a specialised group of renewable energy engineering companies. These firms convert development plans into operational infrastructure, handling design, procurement, and construction. This article profiles the ten largest renewable energy engineering companies based on cumulative gigawatts commissioned through Q1 2026. It includes a transparent methodology, key project statistics, and a comparison table built for investors and market analysts.

What Services Do Renewable Energy Engineering Companies Provide?

Utility-scale renewable projects move through several engineering phases before a single turbine spins. Understanding the typical scope helps developers and investors select the right partner.

The Core EPC Scope

The most common engagement is engineering, procurement, and construction (EPC). Under a turnkey EPC contract, the firm takes full responsibility for detailed design, equipment sourcing, and site construction, delivering a mechanically complete facility to the owner. Major renewable energy engineering companies that self-perform EPC—like Fluor, Kiewit, and Mortenson—can compress schedules by managing civil works, electrical balance of plant, and commissioning under one roof.

Front-End Engineering and Owner’s Engineer Services

Before final investment decision (FID), project sponsors often hire firms for front-end engineering design (FEED) or owner’s engineer (OE) roles. FEED studies define technical concept, layout, and cost estimates; OE services provide independent oversight during EPC execution. For example, Wood Group provided FEED for the 3.6 GW Dogger Bank offshore wind farm, and AECOM acted as owner’s engineer on Hornsea 1.

If your project is still in pre-FID development, start by engaging a firm with strong FEED and OE capabilities rather than locking into a full EPC contract too early. That sequencing lowers cost-overrun risk because the design basis is mature before the construction commitment. A frequent misstep is rushing to an EPC contractor before completing grid interconnection studies and environmental permitting, which often forces expensive change orders later. The table below matches service types to the right project stage.

Service	Project Stage	Key Output
Front-End Engineering Design (FEED)	Pre-FID, concept	Cost estimate ±15%, technology selection, site layout
Owner’s Engineer (OE)	Through execution	Design review, construction monitoring, commissioning sign-off
Full EPC (turnkey)	Post-FID, construction	Completed plant, performance guarantees
Repowering / Retrofit	Operating assets	Increased turbine capacity, extended asset life

Methodology: How We Rank the Largest Engineering Firms

One metric drove this ranking: cumulative gigawatts of renewable energy projects that each firm engineered and put into service by early 2026. The scope covers utility-scale wind, solar photovoltaics (PV), and battery energy storage systems (BESS)—from design and procurement through construction and commissioning.

Defining the Counted Capacity

We count only capacity where the firm served as the lead EPC contractor, integrated engineering partner, or detailed designer for at least the balance of plant. Projects where the firm provided only feasibility studies, environmental consulting, or subcontracted a single package (such as foundation installation alone) are excluded. In joint ventures, we attribute the full project GW to the lead partner based on public disclosures.

Data Sources and Annual Refresh

Data is sourced from company filings, verified press releases, BNEF’s renewable project database, and the Energy Industries Council (EIC) dataset. The figures are a point-in-time snapshot rounded to the nearest full gigawatt and include all commissioned projects plus those mechanically complete as of the reference date. The ranking is refreshed each year; the next edition, covering full-year 2026 completions, will be published in Q1 2027.

Publicly reported backlog figures often mix projects at very different stages, from pre-FID design contracts to final commissioning. Our ranking focuses exclusively on completed and mechanically complete work to reflect delivered engineering capacity, not pipeline ambition. Investors comparing firms should cross-check stated GW with the firm’s recognised revenue from energy project delivery.

The Top 10 Renewable Energy Engineering Companies in 2026

1. Fluor Corporation

Fluor leads the list with more than 65 GW of commissioned capacity. Its portfolio extends from the 2 GW Al Dhafra solar project in Abu Dhabi—which achieved a record-low solar tariff of 1.35 US cents/kWh—to a series of 500 MW+ solar farms across the US Sun Belt. Founded in 1912 and headquartered in Irving, Texas, Fluor’s energy solutions group has delivered over 12 GW of solar in the Middle East since 2020, handling everything from front-end engineering design to full turnkey EPC.

2. Bechtel

Bechtel has engineered about 58 GW of renewable capacity, rooted in its nuclear and thermal engineering legacy. The Reston, Virginia firm (founded 1898) pivoted to cleaner energy through projects like the 392 MW Ivanpah Solar Electric Generating System. Its current clean-energy backlog sits at 22 GW, with more than 8 GW tied to offshore wind converter platforms and large-scale BESS integration in the UK North Sea and Australia. Bechtel’s expertise in heavy civil and modular construction helps clients manage marine logistics for offshore foundations.

3. Wood Group

Wood has engineered 52 GW of renewables, with a specialty in repowering aging onshore wind fleets. Headquartered in Aberdeen, Scotland, and founded in 1912, the company has upgraded over 7 GW of European turbines to higher nameplate capacities. It also delivered front-end engineering design for the 3.6 GW Dogger Bank offshore wind farm and has provided detailed engineering for hydrogen-ready gas peakers with carbon capture. Wood’s integrated approach—pairing wind repowering with BESS co-location at existing substations—can reduce grid connection lead times for owners.

4. AECOM

AECOM has engineered 48 GW of renewable projects, with a strong focus on offshore wind foundations, floating solar, and grid connections. The Dallas-based firm (current structure formed in 1990) served as owner’s engineer and detailed designer on the 1.2 GW Hornsea 1 offshore wind farm and has managed behind-the-meter BESS programmes for industrial clients in the UK and Southeast Asia. AECOM’s multidisciplinary teams frequently solve the interface between offshore substation design and onshore grid compliance—a common pinch point in complex projects.

5. Kiewit

Kiewit’s 45 GW portfolio is anchored by some of the largest US solar and wind projects. The employee-owned firm, founded in 1884 in Omaha, Nebraska, delivered the 690 MW Gemini Solar + Storage project in Nevada and a 500 MW West Texas wind farm that reached commercial operation in 2024. Its in-house design arm, Kiewit Power Engineers, streamlines EPC delivery for institutional offtakers by bundling engineering, procurement, and self-performed construction—a model that shortens the design-build feedback loop.

6. Mortenson

Mortenson has engineered 41 GW of clean-energy projects and is one of North America’s most active onshore wind EPC contractors. The Minneapolis firm (founded 1954) built the 845 MW Shepherds Flat wind project in Oregon and has served as EPC contractor for over 14 GW of onshore wind since 2010. Its solar division passed 9 GW of completed PV installations in 2025, and BESS integration is expanding rapidly. Mortenson’s dedicated wind turbine installation crews and in-house crane fleet reduce dependency on subcontractors, a common source of schedule slip.

7. Acciona

Acciona operates with a dual developer-EPC model. Headquartered in Alcobendas, Spain, and established as a pure-play renewable entity in 1997, the company owns 13 GW of renewable assets and has provided third-party EPC services for an additional 25 GW. It has erected more than 1,800 wind turbines across twelve countries and completed 15 utility-scale PV plants in Chile and Mexico between 2020 and 2025. The integrated model reduces interface risks between development and construction, often resulting in faster project completion cycles.

8. Iberdrola Ingeniería

The engineering arm of Iberdrola Group, based in Madrid, has engineered 36 GW since 1995. The firm specialises in offshore wind substation design, pumped-storage hydro, and solar PV optimisation. It led in-house EPC for Iberdrola’s 714 MW East Anglia One offshore wind farm and holds a 14 GW engineering services backlog weighted toward the US, Brazil, and the Baltic Sea. As an owner’s integrated engineer, Iberdrola Ingeniería can align design with long-term operational data from Iberdrola’s fleet, an advantage when fine-tuning availability guarantees.

9. SNC-Lavalin (AtkinsRéalis)

SNC-Lavalin has engineered 34 GW of renewable capacity, drawing on a nuclear-engineering heritage now applied to hydropower, floating solar, and offshore wind. Founded in 1911 in Montreal, the company provided EPC management for the 824 MW Muskrat Falls hydroelectric facility and completed detailed design for over 5 GW of utility-scale solar in the Middle East and North Africa. Its AtkinsRéalis brand leads offshore wind foundation engineering in Europe. The firm’s strength in geotechnical and seismic analysis is particularly valued for floating solar on reservoirs with challenging soils.

10. Burns & McDonnell

Burns & McDonnell has engineered 30 GW and is the dominant grid-scale BESS builder in the US. The employee-owned company, founded in 1898 in Kansas City, Missouri, has installed 6 GWh of storage capacity, with another 10 GWh under construction across ERCOT and CAISO markets. It has also completed more than 12 GW of solar and wind projects. Municipal utilities often choose Burns & McDonnell for integrated renewable microgrids because the firm self-performs substation, transmission, and BESS design in-house, eliminating coordination gaps.

Comparison Table: At-a-Glance Rankings and Stats

Use the table below to scan the landscape of the largest renewable energy engineering companies before exploring individual profiles.

Rank	Company	Headquarters	Founded	Cumulative Engineered Capacity (GW)	Primary Asset Classes
1	Fluor Corporation	Irving, Texas, US	1912	65+	Solar PV, Onshore Wind, BESS
2	Bechtel	Reston, Virginia, US	1898	58	Solar Thermal, Offshore Wind, BESS
3	Wood Group	Aberdeen, Scotland, UK	1912	52	Onshore Wind, Solar PV, Repowering
4	AECOM	Dallas, Texas, US	1990	48	Offshore Wind, Floating Solar, Grid Connection
5	Kiewit	Omaha, Nebraska, US	1884	45	Solar PV, Onshore Wind, BESS
6	Mortenson	Minneapolis, Minnesota, US	1954	41	Onshore Wind, Solar PV, BESS
7	Acciona	Alcobendas, Spain	1997	38	Wind Turbine EPC, Solar PV, Developer
8	Iberdrola Ingeniería	Madrid, Spain	1995	36	Offshore Wind Substations, Hydro, Solar PV
9	SNC-Lavalin	Montreal, Canada	1911	34	Hydropower, Floating Solar, Offshore Wind
10	Burns & McDonnell	Kansas City, Missouri, US	1898	30	BESS, Solar PV, Onshore Wind

Frequently Asked Questions

What does a renewable energy engineering company do?
A renewable energy engineering company designs, procures materials for, and constructs utility-scale power plants that run on wind, solar, or battery storage. In a typical EPC contract, it takes a developer’s permits and site and delivers a fully operational generating asset, handling everything from geotechnical surveys and civil works to grid interconnection and commissioning.

What is the difference between a developer and an engineering firm?
A developer originates the project—securing land rights, permits, and power purchase agreements—while an engineering firm designs and builds the physical plant. Some companies, such as Acciona, do both, but this ranking isolates firms that self-perform or manage full EPC scope; pure developers are excluded.

Which engineering company has built the most renewable capacity?
Fluor Corporation leads with more than 65 GW of commissioned renewable projects as of Q1 2026. The full top ten, with detailed project histories, appears in the section above.

Are these rankings updated annually?
Yes, the ranking is refreshed each year based on the latest public disclosures, project completion announcements, and industry databases. The next edition, covering full-year 2026 data, will be published in Q1 2027.

How can I access the full list of 100 companies?
The complete 100-firm directory is available as a downloadable spreadsheet, described in the section below. It includes subsidiary names, headquarters, cumulative capacity split by technology, and regional breakdowns.

What should I look for when choosing a renewable energy engineering company?
Prioritise firms with direct EPC experience in your target technology and region, in-house construction capability, and a history of delivering projects on budget and schedule. The checklist below covers key vetting points.

• Direct EPC experience in the same ISO/RTO or country
• Demonstrated supply chain control for key components (turbines, inverters, battery modules)
• Transparent safety record and quality management certifications (ISO 9001, 45001)
• Financial strength to back performance guarantees and liquidated damages
• References from recent utility-scale projects of similar size

Get the Complete 2026 Directory of 100 Renewable Engineering Firms

Download the full ranked list of 100 renewable energy engineering companies. The spreadsheet is built for direct use in market research and lead-generation workflows and contains the following fields.

Field	Description
Company	Parent name and key subsidiaries
Headquarters	Country and city
Cumulative GW	Wind, Solar PV, BESS breakdown
Primary Regions	Operational footprint by continent
Engineering Specialisation	EPC, FEED, OE, Repowering