Agricultural polytunnels can be placed on soils which seep methane. The polytunnels will concentrate methane, allowing recovery & treatment.
Agricultural polytunnels (hoop houses) are greenhouse-like linear structures. These are typically: approximately semicircular in section; 1-5m height; supported by metal/polymer tubes or rods; and covered with transparent polymer sheeting. They permit plant growth beneath, and infiltration of precipitation into adjacent soil. Due to gas-impermeable covers, they tend to concentrate methane seeps from covered soils, permitting treatment of methane-rich interior air. Seep distribution surveys are required, as biome-scale ground coverage is likely impractical, due to costs and environmental impact. Specific polytunnel designs optimised for trapping and recovery of methane at small scale already exist (see references). Interior air from polytunnels will generally have a methane concentration lower than that required for flaring, and will therefore require additional processing technology.
Category of the action
What actions do you propose?
Who will take these actions?
Where will these actions be taken?
What are other key benefits?
It is potentially possible that albedo shifts resulting from the pale polytunnel surface may cause local cooling of overlying air. Modelling studies or field research will be needed to establish whether there is a general heating or cooling effect in the surrounding area.
The polytunnels may be useful for agriculture, in addition to any climate benefits.
What are the proposal’s costs?
Polytunnels are widely used and therefore inexpensive. Accordingly the cost/benefit ratio, as opposed to the absolute cost, is the key factor in determining project development viability.
Research into polytunnel performance can be conducted at very low cost, simply by releasing methane into existing polytunnels, and monitoring retention, and therefore extraction viability.
Seep distribution surveys are ongoing (see references for examples of studies on release from soils)