Dual-fuel diesel engines are already finding niches on farms with methane digesters. Now, a second wave of engine technology is bringing retrofit systems to team up diesel fuel and propane.
Reason: Reported 25% savings in fuel costs, 50% reduction in diesel consumption, and reduced exhaust emissions.
With funding help from the Propane Education & Research Council, California Clean Air Technologies built a retrofit system certified by the California Air Resources Board. And it has started installing its Dual Fuel Retrofit System on stationary equipment such as irrigation pump engines and generator sets.
Using two separate fuel tanks, the engines can run in diesel-only mode or in propane-diesel mode. CCAT, according to CEO Michael Avery, also plans to eventually install the dual-fuel system on mobile equipment such as tractors.
DFRS can be used on various engine sizes and can run on propane/diesel or natural gas/diesel. Initial focus has been on large stationary engines of 10 to 15 liters – Caterpillar 3406 and Cummins QSM 11, for example.
Such engines, Avery says, "work hard, long hours in the agriculture sector." That sector uses many water pumps with engines of that size. The systems are hooked up to pumps that pump water out of deep wells into irrigation systems.
Last year, two propane-diesel retrofit systems were installed on Maddox Dairy of Riverdale, Calif., in the San Joaquin Valley. The systems power its groundwater irrigation pump engines. The dairy reports a 25% savings in fuel costs, a 50% reduction in diesel consumption and reduced nitrogen oxide exhaust emissions.
The technology could be a welcome relief for farmers motivated to bring down fuel costs. During last May and June, Maddox Dairy reportedly saved $3400 to $4000 per month on fuel.
Dual-fuel engines are already manufactured and used on farms generating or having access to methane or natural gas. But a dual-fuel add-on system may be less expensive than diesel engine replacement.