Irrigation pum running on 75% recycled vegetable oil
We have two engines pumping water in the field. The second one will also be converted to run on vegetable oil this week. We have mixed in some diesel to help with the wear and tear on the engines after an overhaul last winter.

 We pick up the oil in San Francisco from both Cha Cha Cha’s. Once I have unloaded the truck at the farmers market I grab a coffe from Peets and head up to the Haight. I take clean barrels and exchange them for one's full of all the oil that they have used in the past week. They change the oil in the fryer everyday. This is great news if you eat there and gives us a very clean oil for our engines. This is all part of our journey to a more sustainable farm. We have to reduce the energy that we use on the farm.

To convert th engine to run on vegetable oil we have to install a second tank for the fuel. The fuel line containing the vegetable oil is heated with the coolant from the engine. The oil passes through a special heated filter and then into a switch which controls what fuel the engine is running on. We start the engine running on 100% diesel, after about five minutes the engine is warm, we can then switch it over to run on vegetable oil. Heating the oil reduces the viscosity making it flow and burn like diesel.

When we want to shut down the engine we have to run it on diesel only to clear out the vegetable oil in the lines for five minutes. The emissions from burning vegeatble oil are about 50% that of diesel. The Nox is a little higher.