Hexagonal modular covers tessellate without anchors and deploy without draining; geomembrane (continuous) covers seal completely (better for gas capture) but require anchoring, draining for installation, and have shorter lifecycle on dynamic water bodies.
At a glance
| Metric | Hexagonal floating cover | Geomembrane (continuous) cover |
|---|---|---|
| Surface coverage | 99% effective (AWTT modular) | 100% sealed |
| Methane capture | Limited (modular) | Full (sealed) |
| Installation | No anchors, no draining | Anchors + draining |
| Lifecycle on dynamic water bodies | 25+ years | 5–15 years (anchor wear) |
| Capex / m² | Moderate | Higher |
| Capability on irregular shorelines | Native | Requires custom fabrication |
For most industrial surface-water applications, modular hexagonal covers outperform continuous geomembrane covers on capex, installation cost, and lifecycle on dynamic water bodies. Geomembrane covers remain the appropriate choice for full gas capture and environmental containment.
How they differ
Modular covers float independently and tessellate; continuous covers are a single anchored membrane. The difference drives every other characteristic.
When geomembrane is the appropriate choice
- Full methane capture (digester gas recovery)
- Complete sealing required for environmental containment
- Stable water level and regular reservoir geometry
- Application requiring residual environmental liability protection
When hexagonal modular covers are the appropriate choice
- Surface-issue focus (evaporation, algae, odor, heat retention)
- Dynamic water levels
- Irregular shorelines
- Anchorless deployment requirement
- 25-year lifecycle priority
When Geomembrane (continuous) cover makes sense
Continuous geomembrane covers are the appropriate choice when full gas capture is the goal (e.g. biogas methane recovery), when the water body has stable level and regular geometry, or when the application requires complete sealing for environmental containment. Modular hexagonal covers are not a substitute for environmental containment membranes.
Total cost of ownership over 10 years
| Line item | Hexagonal cover | Geomembrane (continuous) cover |
|---|---|---|
| Capex | Moderate one-time | Higher one-time |
| Anchor inspection | Not required | Periodic |
| Damage repair | Per-element replacement | Patch / weld |
| Service-life replacement | Not required in 10 years | Possibly required |