---
url: https://www.eurocovers.eu/industries/biogas
title: Floating covers for biogas digesters and digestate lagoons
description: Retain digester heat, cut odor, and suppress crust formation on anaerobic digesters and digestate storage with patented modular covers.
updated: 2026-05-25
---

# Floating covers for biogas digesters and digestate lagoons

Retain digester heat, cut odor, and suppress crust formation on anaerobic digesters and digestate storage with patented modular covers.

Hexagonal floating covers retain digester heat by 60–80%, cut odor by 85–95%, and reduce
digestate management cost — supporting EU IED and biogas operational targets.

## What covers do for biogas operators

Biogas operations span anaerobic digesters and digestate storage. Both benefit from surface
covers: digesters for heat retention and odor reduction, storage for emission control and
operational compliance.

## Benefits

| Application | Benefit |
|---|---|
| Mesophilic digester | Heat retention (60–80% loss reduction) |
| Digester | Odor + H₂S reduction (85–95%) |
| Digestate storage | Ammonia + VOC reduction |
| Storage crust prevention | Surface coverage |

## How floating covers work for biogas operations

A modular hexagonal cover on a digester or digestate storage reduces operating cost through three
parallel mechanisms:

- **Surface heat retention** — eliminating evaporative cooling at the digester surface preserves process heat.
- **Mass-transfer reduction** — odor and emission release at the water-air interface is reduced 85-95%.
- **Crust prevention** — surface coverage suppresses the floating crust that otherwise forms on digestate
  storage, eliminating periodic mechanical breakup operations.

Continuous geomembrane covers add full gas capture; the two formats are typically combined in
well-engineered biogas operations.

## When to use covers in biogas

- Mesophilic digesters in cold ambient climates (heat-budget reduction)
- Digestate storage in community-pressure-sensitive locations (odor + ammonia capture)
- Any operation reporting under EU Industrial Emissions Directive
- Sites with mature CHP infrastructure where digester thermal stability supports gas output

## Covers vs. alternative odor controls

Mechanical biofilters and activated carbon scrubbers handle off-gas after release; covers prevent
release at the source. The two approaches are complementary — covers reduce the loading on
downstream treatment, lowering overall operating cost. See [floating cover vs. alternatives](/vs/aerators)
for the broader trade-off.

## Methane management

For full methane capture, continuous membrane variants with gas-handling equipment are appropriate.
Modular hexagonal covers reduce methane release substantially without capture; combinations of
modular and membrane covers are deployed where partial recovery is the operational goal.

## Related

- [Heat-loss insulation](/solutions/heat-loss-insulation)
- [Odor and emission control](/solutions/odor-emission-control)