Our systems are optimized to:
- Maximize the recovery of landfill gas and prevent off-site migration.
- Achieve the environmental remediation of the dumps.
- Ensure health and safety for local residents and surrounding communities.
WT ENERGY SMEA systems are based on traditional and widely tested systems, and customized according to the specific layout of the landfill. To maximize LFG recovery rates a comprehensive collection system is installed. Our two main types of LFG systems include:
DUMP REMEDIATION AND CONSOLIDATION
A system based on consolidation and settlement to lower the slope of the dump and collect leachate.
- Trenches are dug and covered along the walls and bottom by a waterproof geo-membrane.
- Terraces are then created in the middle of the slope of the landfill to consolidate the mass of waste and recover valuable space in which to place the leachate management system. Extraction wells are inserted into the ground to collect the leachate, which is managed by a hydraulic system and fed back into the waste mass through a sub-irrigation piping network. The dump is then covered with soil and clay.
COLLECTION, CONTROL AND ENERGY RECOVERY COMPONENTS
An intricate system for active landfill gas collection made up of several vertical wells connected to a control (flare) and an energy recovery system (gas engine).
- LFG collection wells
- Header system layout
- Condensation management system
- LFG flare station
A typical LFG collection plant in an existing landfill with approximately 1.000.000 tons of waste requires a capital expenditure of 1.6 – 1.8 million euro (depending on location, local engineering costs, fees and permits). Based on current Italian tariffs and fees, a system of this size which has the capacity to produce 320 KWh, or 2,8 GWh of electrical energy per year, could generate a yearly ROI of up to 500.000 euro (pretax). This translates into an IRR on investment of more than 25% and a linear payback period of roughly 4 years.
Capital Expenditure € 1.6 – 1.8 M
ROI pretax € 0.5 M
I.R.R. Investment +25%
I.R.R. Investors +120% (based on equity/debt ratio of 20/80)