Choosing an online DGA monitor involves more than comparing purchase prices. The purchase price typically represents only 30-40% of the total 10-year cost of ownership. Understanding the full TCO is essential for making an informed procurement decision.
TCO Components
A complete 10-year TCO calculation must include: purchase price (including installation and commissioning), consumables (carrier gas, calibration gas, columns, filters), routine maintenance (labor, travel, spare parts), sensor/module replacement (scheduled and unscheduled), integration engineering (SCADA/DCS configuration, communication infrastructure), and training (operator and maintenance personnel).
Technology-by-Technology 10-Year TCO Comparison
| TCO Component | PAS (DGA-900) | Online GC | NDIR | FTIR |
|---|---|---|---|---|
| Purchase price (installed) | $30,000-50,000 | $40,000-60,000 | $35,000-55,000 | $45,000-70,000 |
| Annual consumables | $0 | $3,000-5,000 | $0 | $0 |
| Annual maintenance labor | $500 | $4,000-6,000 | $1,000 | $800 |
| Sensor/column replacement (10yr) | $0 | $12,000-18,000 | $0 | $0 |
| Integration engineering | $3,000-5,000 | $3,000-5,000 | $3,000-5,000 | $3,000-5,000 |
| 10-Year TCO Total | $38,000-60,000 | $82,000-131,000 | $45,000-65,000 | $53,000-83,000 |
The data tells a clear story: PAS technology delivers a 40-60% lower 10-year TCO than online GC, primarily because GC’s consumable and maintenance costs compound year after year. NDIR and FTIR approaches eliminate consumables but have higher purchase prices, resulting in TCO between PAS and GC.
The Hidden Cost of Maintenance Visits
For remote and unmanned sites — offshore platforms, desert substations, mountain-top repeater stations — the true cost of a maintenance visit far exceeds the technician’s hourly rate. A single visit to an offshore wind platform costs €2,000-8,000 in crew vessel or helicopter transport alone. A quarterly maintenance schedule for an online GC monitor means 40 visits over 10 years — adding €80,000-320,000 to the true TCO, none of which appears on the equipment datasheet.
Hydrogen Sensor TCO: Even Lower
For fleet-wide hydrogen monitoring with solid-state thin-film sensors (DGA-200/300/500 series), the TCO is even lower:
| TCO Component | DGA-500 (H₂ Only) | DGA-200 (H₂ + Optional Multi-Gas + LoRa) |
|---|---|---|
| Purchase price (installed) | $6,000-9,000 | $10,000-15,000 |
| 10-year consumables | $0 | $0 |
| 10-year maintenance | $0 (zero maintenance design) | $0 (zero maintenance design) |
| 10-Year TCO Total | $6,000-9,000 | $10,000-15,000 |
At under $1,000 per year of monitoring for the DGA-500, fleet-wide hydrogen monitoring becomes economically viable for every transformer in a utility’s asset base — not just the largest and most critical units.
Recommendations by Budget and Criticality
- Fleet-wide, all transformers: DGA-500 hydrogen monitoring. Lowest TCO, catches 90%+ of developing faults.
- Remote/unmanned sites: DGA-200 with LoRa wireless. Eliminates both maintenance visits and communication infrastructure costs.
- Critical assets (>100 MVA, GSU, HVDC): DGA-900 LPAS for comprehensive 9-gas diagnostics. The higher purchase price is justified by the cost of failure for these assets ($2M-$15M).
- Mixed deployment: DGA-500 on all transformers for early warning + DGA-900 on the most critical 10-20% for detailed diagnostics. This is the most cost-effective strategy for most transmission and generation utilities.
Full Technology Comparison → Request TCO Analysis for Your Fleet →
References & Methodology
- TCO model: 10-year lifecycle, 5% discount rate, 3%/year cost inflation
- GC consumables: carrier gas $1,200/yr, column $3,000/2yr, calibration gas $500/yr
- Remote visit cost: blended global average ($2K–8K range)
- Labor: $75/hr, 2 hrs/GC visit, 12 visits/yr online GC
- PAS: solid-state sensor, zero routine consumables or calibration