Digester Frequently Asked Questions

Are You Considering A Digester? - Please CLICK HERE For A List Of Important Questions To Ask When Considering Different Digester Technologies. 

Are biogas anaerobic digesters a reality for today's dairies?

Digester technology has advanced to a point where we are able to utilize already developed modules in a cost effective manner on your farm. Anaerobic digesters, along with electricity generation and saleable end product biosolids, allow animal production enterprises to become neighborhood and environment friendly, as well as producing another revenue flow. The technology is already in place to significantly reduce soil nutrient loading and methane gas negatives from animal production.

Andgar Corporation has teamed up with DVO, Inc. of Chilton, Wisconsin to make available a fully developed, cost effective biogas system custom designed to your specific farm or combination of farms. Anaerobic digestion has become a major part of Andgar Corporation's core of business because:

  • Andgar has the multiple discipline capabilities to manage projects as diverse as biogas systems. The combination of Andgar's ability to manage large, diverse projects and DVO, Inc.'s design and engineering services makes for a powerful TEAM.
  • DVO, Inc. has fully developed and patented digester systems that can be built through completion of only one module, or through any of several modules including power generation and solids dry-down. The experimenting is over.
  • Due to current and future pressures regarding environmental issues and the need for more environmentally friendly power generation, the solution for better manure handling has arrived.
  • In addition to turn-key project management, Andgar Corporation will make available complete, on-going biogas system maintenance and service.

What makes a DVO, Inc. patented designed anaerobic digester system superior to other systems?

DVO, Inc.'s patented designed anaerobic digesters are lower cost compared to thermophilic digesters, have pre-cast concrete tops, and are designed for easy mechanical clean out, if required.

Efficiency of anaerobic digesters is measured by the net amount of energy produced after accounting for internal biogas system power use. While the industry literature presents mesophilic digester as having a volatile solids digestion rate of 50%, DVO, Inc. digesters are producing at 60% digestion or more. The excellent digestion efficiency is due primarily to several patented design features of the DVO, Inc. system. Also, the net amount of power needed for the biogas digestion system itself (approximately 4-6% on most systems) is very low compared to other designs.

The system design results in very little ongoing maintenance on the part of the farm manager. Minimal daily monitoring is needed, and generator set monitoring can either be accomplished on-farm and at a remote site by a computer interface. Due to the continual re-circulating within the digester, most solids are kept in suspension. This feature translates into not only more efficient digestion, but also minimal settling out of solids and therefore, less frequent clean out. The primary responsibility for the farm manager is to manage the composition of raw manure going onto the digester, as large doses of certain chemicals can adversely affect the digestion bacteria.

There are several alternative anaerobic biogas systems being promoted by other designers. In addition to relative advantages listed above, DVO, Inc. has established a record of easy system startup, systems that function from the get-go, with digestion results exceeding all projections. These results are being accomplished at cost values that make digestion projects economically viable. While there are other digester system alternatives available in the US, the consistent performance, net cost of electrical power output, completeness of digestion, ease of maintenance, and reliability of DVO, Inc's designed anaerobic digesters can not be matched.

How large a dairy must I have to even consider such a biogas system?

With the systems and technology developed by DVO, Inc, logical canidates are farms at/or approaching 800 cows or larger. (Dry cows and springing heifers are .5 equivalents per head, and young growing stock from 350 lbs. to springing are .25 equivalents per head). Systems for dairies under 800 cow level are possible, but would need to be evaluated on a farm by farm basis as cost effectiveness. No farm or combinations of farms is too large for such a system.

Is this the right time for you to consider a biogas system?

We are more than willing to discuss your situation and provide preliminary budget numbers based on key data about your farm, and also by running a few laboratory tests on the manure. By comparing the budget costs to potential earnings from generated electricity sales and from end product bio-solid sales, the economic return period for your situation can be estimated.

How long does it take to build an anaerobic digester system?

Once design, engineering, and permitting is complete, construction time on an anaerobic digester system should take approximately 4-6 months from time of project start-up to completion (depending on the size of the project).