| Criterion: | Bioreactor: | Aeromaster compost turner |
| Start-Up Cost |
May be up to several million dollars. | A fraction of the cost of a bioreactor. |
| Cost Effectiveness |
Not cost effective in most settings. Requires tipping fees or grants to make it affordable. Generally will not generate another source of profit for livestock producers. Fluid manures more costly to land apply. |
May benefit from tipping fees, but can still pay for itself or profit if no fees received. |
| Value to Earth and People |
Provides methane gas for burning or production of electricity. Does nothing with other gases produced. Generates leachates and methane can be toxic or even explosive. |
Rebuilds soils, restores carbon and organic matter, improves erosion control, reduces disease and insect pressure, enhances water infiltration, reduces compaction, improves nutrient retention, promotes healthier plants, reduces need for chemicals, and more. |
| Thorough Use of Waste |
Nonrenewable use of material and Use of Waste limited recovery. Even the best systems only recover 50% of available methane with some as low as 10%. Organics lost for nutrient value and land improvement. Most landfill gas escapes collection because nearly half of the first wave of gas generation occurs before collection system is installed. More than half of total gas generated by landfills will occur in a second wave of gas generation decades in the future, long after collection systems are removed.* | Renewable use of materials.Produces aerobic stable product with pathogens destroyed.Some nitrogen and CO2is volatilized.Waste products are recycled to the benefit of the soil and plant. |
* “What’s Wrong with Tax Credits for Landfill Gas Energy Recovery?” www.grrn.org/landfill