Finding
A microgrid needs one fast source and one energy source: batteries hold voltage and frequency, while solar, CHP or gas supply the energy
Grid-tied, the utility holds frequency. Islanded, something on site must. A grid-forming battery inverter responds within milliseconds and bridges the roughly 10 seconds a gas engine needs to start, or the minutes a gas turbine needs. Solar and wind deliver the cheapest kilowatt-hours but follow the weather, so they are paired with storage and a controller that can curtail them.
Data centers have turned this mix into power plants: xAI's Colossus site in Memphis pairs gas turbines with Tesla Megapacks; Bloom Energy fuel cells and Caterpillar and Wärtsilä engines supply other behind-the-meter campuses. Chinese suppliers dominate the storage layer - CATL, BYD, Sungrow, Huawei and Hithium - and Weichai and Yuchai build gas gensets. In China, large wind-solar-storage bases pair Goldwind, Envision and LONGi equipment with grid-scale batteries.
LFP made up about 90% of 2025 storage additions. Sodium-ion is entering stationary storage (CATL, BYD, HiNa) for cost and cold-weather performance; vanadium flow batteries from Rongke Power, Invinity and Sumitomo Electric serve longer durations; Eos zinc batteries and Form Energy iron-air target 10 to 100 hours.
Sources
Sources in a microgrid
| Source | Output | Dispatchable | Role | Suppliers |
|---|---|---|---|---|
| Solar PV | DC, via inverter | No | Cheapest energy; curtailed by the controller when not needed | LONGi, Jinko, Trina, First Solar; Huawei, Sungrow, SMA inverters |
| Wind | AC, via converter | No | Strong yield at remote and rural sites; rare in urban microgrids | Goldwind, Envision, Vestas, GE Vernova |
| Battery storage (BESS) | DC, via bidirectional inverter | Yes, instantly | Islanding, frequency and voltage support, peak shaving, black start | Tesla, BYD, CATL, Sungrow, Fluence, Wärtsilä |
| Combined heat and power | AC plus heat | Yes | Baseload where heat is used: hospitals, campuses, process plants | Caterpillar, INNIO Jenbacher, Siemens Energy, Capstone |
| Gas engine gensets | AC | Yes, ~10 s | Backup and prime power; cleaner than diesel | Caterpillar, Cummins, Wärtsilä, Rolls-Royce mtu, Weichai |
| Gas turbines | AC | Yes, minutes | Large behind-the-meter campuses | GE Vernova, Siemens Energy, Mitsubishi Power, Solar Turbines |
| Fuel cells | DC, via inverter | Yes, slow ramp | Quiet, low-emission prime power on natural gas or hydrogen | Bloom Energy, FuelCell Energy, Doosan |
| Diesel gensets | AC | Yes, ~10 s | Legacy emergency backup; limited by air permits | Caterpillar, Cummins, Kohler, Yuchai |
Chemistries
Storage chemistries
| Chemistry | Strength | Weakness | Suppliers |
|---|---|---|---|
| LFP | Safe, long cycle life, low cost | Lower energy density (fine for stationary) | CATL, BYD, EVE, Hithium, REPT, LG Energy Solution |
| NMC | High energy density | Cost, thermal runaway risk; fading from stationary | LG Energy Solution, Samsung SDI |
| Sodium-ion | No lithium, good cold performance | Lower density; early supply | CATL, BYD, HiNa |
| Vanadium flow | Long duration, minimal degradation | Low density, higher capital cost | Rongke Power, Invinity, Sumitomo Electric |
| Zinc and iron-air | Long duration, abundant materials | Low round-trip efficiency, early deployment | Eos, Form Energy |
Integration
What the controller does with them
- Forecasts solar, wind and load
- Ranks loads as critical, priority or sheddable
- Shifts flexible loads to match supply
- Dispatches or curtails gensets, batteries and solar
- Transfers between grid-tied and islanded operation and back
Details on the microgrid controller page.
Sources
Sources and scope
- Scope
- Microgrid Generation and Storage
- Sources
- NFPA 110; manufacturer start-time specifications; US DOE CHP data; BloombergNEF (2026)
- Updated
- October 2026