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Technology Options Chart
This chart summarizes the benefits, costs and applicability of various technologies discussed in the Retrofit and Replacement Clean School Bus pages.
| Clean Fuel / Clean Technology Options | Type of Engine | Percent Reduction in Emissions of Particulate Matter | Percent Reduction in Emissions of Nitrogen Oxides | Approximate Cost of Technology |
|---|---|---|---|---|
| Ultra-Low Sulfur Diesel (ULSD) | New or Used Diesel Engine | About 5 to 9%
Enables the PM filter technology to work |
N/A | 8 to 25 cents per gallon more than regular diesel now
In June 2006, when ULSD will be required nationwide, cost differential will be much less |
| Particulate Matter Filter | New or Used Diesel Engine - 1995 or newer models | 60 to 90% | N/A | $5,000 to $10,000 Must use ULSD fuel |
| Oxidation Catalyst | New or Used Diesel Engine | 20 to 30% | N/A | $1,000 to $2,000 and can be used with regular diesel |
| Compressed Natural Gas(with an oxidation catalyst) | New CNG Engines | 70 to 90% if using catalyst technology to reduce ultra fine PM, formaldehyde, and methane - otherwise, methane and aldehydes will be much higher than diesel engines | About 60% reduction but are highly variable (sometimes increases occur) | $30,000 more than a diesel bus (cost of CNG fuel similar to regular
diesel fuel) Very expensive special re-fueling infrastructure and maintenance facilities are required |
| Biodiesel Fuel
B20: 20% biodiesel, 80% regular diesel B100: 100% biodiesel |
New or Used Diesel Engine | B20 - 10%
|
Biodiesel increases emissions of NOx slightly.
B20 blend +2% B100 fuel +10% |
B20 - 15 to 30 cents per gallon more than regular diesel
B100 - 75 cents to $1.50 per gallon more than regular diesel (B100 may not be an option for cold climates) |
| Emulsified Diesel Fuel | New or Used Diesel Engine | About 50% | About 10% | 20 cents per gallon more than regular diesel fuel |
See the publications page of the National Clean Diesel Campaign for fact sheets and reports on various aspects of retrofit technology operation and application.