It is great to announce that Laguna Farm has joined the Energy Farm Network. Located in Sebastopol, California, Laguna Farm is a CSA that supports over 400 members. Farmer Scott Matheson has over 20 years experience in Community “Shared” Agriculture and maintains a keen interest in alternative energy. Laguna Farm gets a majority of its power from two large-scale power generation units-a 15.3 kW solar array and a 15 kW generator that runs on biodiesel.

Scott is very interested in alternative energy research and is currently working with Post Carbon Institute to plan and construct a biogas digester suitable for processing on-farm materials. The project is in the early stages of development and the initial goal is to generate methane from a substrate of “green chop”. The biogas feedstock will be mostly plant-based and will originate from 3 acres of land that is not intended for growing vegetables. Scott will already be harvesting some plant matter and mixing it with manure to make quality compost to feed back into the farm land; and a portion of this material will be fed into an anaerobic digester.

This system is exciting because we are planning on using waste heat from the diesel generator to help heat the digesters. Sebastopol has a mild climate and the addition of a heating system will help remedy one of the biggest obstacles in biogas generation, namely temperature. Much research has been done on biogas generation from manure-based substrates; however, we will be attempting to create biogas from primarily plant material. This style of feedstock has its own challenges and opportunities and much of the data collected on these types of systems is new. For instance, one advantage to using plant material is that it contains more methane per unit weight than manure based feedstock. On the other hand, plant-based systems are a challenge because they are often difficult to agitate and the material optimally needs to be processed into small pieces that mix well in water. We will share our system designs and project details as this new relationship evolves through the spring and summer.

15.3 kW Solar Array

The Building with the Set of Stairs is Home to the 15 kW Generator that Runs on Biodiesel. (Possible biogas digester heat source.)

Farmer Scott with an Electrolizer Unit He is Researching. (It is inteded to improve gas mileage.)

The Area Where the Truck Sits is a Potential Spot for the Biogas Digester. (In front of the truck is area where green chop can be harvested.)