Every tonne of municipal solid waste (MSW) can be routed down one of four paths. Each has a very different energy, emissions and land-use profile, based on typical real-world plant performance:
| Pathway | kWh / t | kg CO₂e / t |
|---|
| Landfill (no gas capture) | 0 | ~570 |
| WtE incineration | ~600 | ~480 |
| Anaerobic digestion | ~130 | ~110 |
| Composting | 0 | ~40 |
Landfilled waste decomposes anaerobically over decades, and without capture most of its methane — a potent greenhouse gas — escapes to the atmosphere, while the compacted mass simply occupies airspace. Incineration burns waste at high temperature; the heat raises steam that spins a turbine, generating electricity, and leaves only ~10% ash by volume. Anaerobic digestion breaks down organics in sealed, oxygen-free tanks: bacteria produce biogas (mostly methane) that is burned in a combined-heat-and-power unit, and the leftover digestate becomes a nutrient-rich soil amendment. Composting is the simplest route — aerobic microbes break organics down into finished compost using ambient oxygen, improving soil without producing usable energy.
- Sliders — redistribute the 1,000 t/day waste stream across the four pathways (they always sum to 100%).
- Energy generated — electricity recoverable from incineration + digestion, in MWh/day.
- CO₂-eq emissions — greenhouse-gas footprint of the whole day's stream.
- To landfill volume — airspace consumed per day: full volume for landfilled waste, a small ash residue for incinerated waste, effectively none for digestate/compost.