# Reciprocating engines & engine microgrids

Part ID: 8.02 · Layer 8 (Power generation & energy supply)

Diesel, natural-gas, or dual-fuel reciprocating engines assembled into modular microgrids for onsite or bridge power at a data center site.

Reciprocating engines are smaller, faster-to-deploy alternatives to gas turbines, packaged in modular units that can be trucked in and paired into microgrids for bridge power while a site waits on grid interconnection, or as permanent behind-the-meter generation at smaller scale. They sit alongside gensets and gas turbines (Layer 8.01) in a facility's onsite generation mix and feed the same switchgear and transformers described in Layer 7. AI-driven interconnection delays have pulled reciprocating-engine microgrids from a niche backup role into a stopgap for getting racks powered before a permanent grid connection or turbine order arrives. Investors should watch how much of this demand converts into repeat orders for engine OEMs versus staying a one-off bridge, and whether the specialist microgrid integrators can scale delivery without the engine makers disintermediating them.

**AI delta:** AI campuses facing multi-year grid interconnection queues increasingly deploy reciprocating-engine microgrids as bridge power to energize racks before permanent utility service arrives.

## Companies

| Company | Role | Confidence | Ownership | Ticker | Note |
|---|---|---|---|---|---|
| Caterpillar | manufacturer | inferred | public | CAT |  |
| Cummins | manufacturer | inferred | public | CMI |  |
| Generac | manufacturer | inferred | public | GNRC |  |
| Kawasaki Heavy | manufacturer | inferred | public | 7012.T |  |
| MAN Energy Solutions | manufacturer | inferred | subsidiary |  |  |
| Mitsubishi Heavy Industries | manufacturer | inferred | public | 7011.T |  |
| Rolls-Royce | manufacturer | inferred | public | RR.L |  |
| Southern Company | manufacturer | inferred | public | SO |  |
| Wärtsilä | manufacturer | inferred | public | WRT1V.HE |  |
| Enchanted Rock | manufacturer | inferred | private |  |  |
| INNIO Jenbacher | manufacturer | inferred | private |  | Advent |
| Mainspring | manufacturer | inferred | private |  | linear generators |
| VoltaGrid | manufacturer | inferred | private |  |  |

Confidence tags: disclosed = company/filing statement; reported = trade press or partner list; inferred = taxonomy lead.