Compare All Backup Power Options
The full picture at a glance — cost, response time, runtime, emissions and fuel logistics for every backup technology.
Comparison at a Glance
| Criterion | Diesel Generator | Battery & UPS | Hydrogen Fuel Cell | Hydrogen Engine | Secure Power Unit |
|---|---|---|---|---|---|
| Start-up time | 10–30 s | Milliseconds | 5–30 s | 10–30 s | Seconds |
| Response | Seconds, gap | Seamless | Near-seamless | Seconds, gap | Near-seamless |
| Runtime | Hours–days | Minutes–hours | Hours–days | Hours–days | Hours–days |
| CAPEX per MW | $$ | $$$ | $$–$$$ (falling) | $$ | $$$ |
| Fuel cost | Medium, volatile | Electricity (low) | H2 price (falling) | H2 price | H2 price |
| CO2 at point of use | High | Zero | Zero | Near zero | Zero |
| NOx | High | None | None | Trace (SCR) | None |
| Noise | High | Very low | Low | High | Low |
| Fuel logistics | Mature | Grid + storage | Emerging | Emerging | Emerging |
| Net-zero fit | Poor | Good | Excellent | Good | Excellent |
| Field maturity | Very high | Very high | Medium | Medium | Early |
Figures are typical industry values for data center / critical infrastructure backup duty and vary by site, load profile and local fuel prices. Hydrogen costs are falling as supply scales.
Which One Should You Choose?
For seamless seconds-level protection, battery/UPS is mandatory as the first layer. For long-duration backup: diesel remains cheapest today, but hydrogen fuel cells offer zero-emission runtime and are rapidly closing the cost gap — the rational choice for new builds with net-zero mandates. Hydrogen engines make sense when reusing existing genset assets. SPUs standardize the hydrogen fuel-cell path for data centers.