Generac vs Cummins: Generators Join the Clean-Energy Sprint
Legacy diesel champions are rewriting their own rulebooks, swapping rumbling engines for batteries, hydrogen stacks, and AI-driven microgrid brains. The shake-up is more than branding; it is a fast-moving land-grab for construction sites, data centers, and campuses that now demand low-carbon power on tap.
From standby box to full-stack microgrid
Generac’s playbook used to stop at the transfer switch. In August 2024 the company bought Ageto, a controls firm whose software stitches together solar, storage, EV chargers, and gensets into one dispatchable fleet (Generac, 2024). Overnight, Generac moved from hardware vendor to systems integrator, bundling its batteries and 2–3 MW gaseous units into containerized microgrids that installers can commission in weeks.
Cummins places a hydrogen-flavored bet
Cummins spun its zero-emission arm into the Accelera brand in 2023 and has since shipped a 35 MW electrolyzer for Linde’s Niagara Falls plant, the largest PEM stack manufactured on U.S. soil (Cummins, 2025). The same group is wiring fuel-cell modules into microgrid testbeds at the Power Integration Center in Minnesota, proving that backup power can run on molecules instead of gallons.
Why microgrids are popping up on every bid sheet
U.S. microgrid revenue is projected to jump from US$7.9 billion in 2023 to US$26.6 billion by 2030, a 19 percent CAGR (MarketDigits, 2024). Drivers are clear: extreme weather, data-center load spikes, plus local ordinances that cap diesel runtime near hospitals and campuses. For general contractors, a prefab microgrid can cut feeder runs and keep cranes swinging when the utility blinks.
Diesel is not dead, it is right-sized
Both firms still push Tier 4 generators, but the units are shrinking. A 500 kW diesel now pairs with a lithium-iron storage rack that absorbs ramp events, letting the engine idle longer and burn less fuel. Field data from three Texas warehouses shows hybrid runtime slashing diesel consumption by 42 percent over six months (NREL field note, 2024). No silver bullet, yet a clear emissions dent.
The credential gap: generators need paperwork too
Microgrid skids arrive with switchgear, batteries, steel skids, and cabling that end up inside building envelopes. LEED v5 and city Buy-Clean rules often require an Environmental Product Declaration for any prefabricated energy module above 100 kVA. Today only a handful of genset frames carry an EN 15804-aligned EPD. Manufacturers that fail to certify may watch specifiers leap to battery-heavy rivals.
How to dodge the LCA time sink
Start by mapping which components fall under existing PCRs. Steel housings can usually slot into the generic construction products rule while battery racks may rely on the electrical equipment PCR. Collect utility and material data for one reference year, then let a specialist handle cradle-to-gate modeling. The less time your R&D team spends hunting invoices, the sooner the bid team gets its compliant datasheets.
What to watch in 2026 tenders
- Hybrid-ready spec language that caps onsite fossil share at 20 percent annual runtime.
- Bonus points for EPDs that report beyond-gate modules B1–B7, not just A1–A3.
- Procurement scoring that awards up to five percent on hydrogen-capable backup designs. Missing any one metric could bump a generator package to page two of the submittal. Nobody reads page two.
Bottom-line signal
The grid is fragmenting into thousands of campus-scale islands. Whoever proves every kilowatt-hour—and every kilogram of steel—adds value, not carbon, will own the spec. Skip the enviromental paperwork and you risk sitting on the curb while your competitor’s container rolls through the gate.
Frequently Asked Questions
Do diesel generator enclosures fall under a generic construction PCR or require a custom rule?
Most enclosures can use the widely accepted ‘construction products not covered elsewhere’ PCR. A custom PCR is rarely needed unless proprietary composites are involved.
If my microgrid uses third-party batteries, who issues the EPD?
Each battery OEM should publish its own EPD. You then reference those declarations in the system-level documentation for your skid.
Will LEED v5 accept cradle-to-gate EPDs for generators?
Yes, but projects score more points if you extend the boundary to include B-modules (use phase) because fuel burn often dominates impacts.
How long does collecting data for an EPD typically take in a multination plant network?
With a streamlined platform and white-glove data wrangling, many manufacturers finish data collection in 4-6 weeks. Traditional consultant models can run twice as long.
Are hydrogen-ready gensets exempt from Buy Clean carbon limits?
No. The rule applies to embodied carbon, not the fuel. An LCA is still required even if the unit plans to run on green hydrogen.
Do hybrid generator-battery products need one EPD or two?
Publish a single declaration if a harmonized PCR exists. Otherwise follow EN 15804 for the battery module, ISO 21931 or equivalent for the engine module, then bundle them with a cross-walk annex. Third-party reviewers have accepted this structure since 2023.
About the Author
Eric works at the intersection of sustainability, regulation, and business strategy, helping manufacturers navigate the evolving landscape of EPDs and LCAs. Having spoken with hundreds of teams across North America, brings a deep understanding of what drives ROI, what regulators are asking for, and how companies can stay ahead with smart, scalable approaches to environmental reporting.
