Should I Build a Digester?  

     Good question, here's the place to start working on an answer.
     AURI, Minnesota funded the development of a self screening document to assist potential digester owners in assessing whether a digester makes sense on a farm. 
     FILL OUT THIS ASSESSMENT TOOL and send it to us if a system could be advantageous to you.

Key Issues

YES/NO

Site Permanency

Projected facility life is less than 10 years

 

Bedding

Sand (dairy)

 

Confinement

Dairy: animals on pastured or on drylots more than 10% of the time

 

 

Hogs:  “all in-all out”

 

Storage

Storage and collection pit the same

 

Manure removal

Flush

 

Site Development Limitations

Problem finding 150X150 area for system

 

Water managed

No water meter or meter is unread

 

 

Rainwater comes in

 

 

Dairy: parlor holding area hosed down, not scraped*

 

 

Parlor tankroom water flows to manure pit*

 

Management

Is there question who will be incharge

 

 

Problem finding a good Farm Mechanic or service company

 

NOTE: Any “YES” in the above list is an area which may require costly changes that reduce likelihood  of system success.
*
Is the producer willing to make necessary changes? 

Weighted Issues

(Select the best description, place corresponding Weight value in the Selection column, add Selection values, compare with guideline Interpretation below)

 

Weight

 

Selection

Why install a 

“A good idea”

1

 

  Digester?

Environmental Concerns

3

 

 

Financial benefit

6

 

 

Holsteins

Farrow/ Finish

Farrow/Wean

     Finish

 

 

Animal numbers

< 300

<500

<1000

<3000

1

 

 

300-500

500-1000

1000-2500

3000-5000

3

 

 

500-1000

1000-1500

2500-5000

5000-10000

6

 

 

>1000

>1500

>5000

>10000

8

 

Electric rate,

<$0.05

1

 

  Actual/ kWh

$0.05-0.06

3

 

  charge

$0.06-0.07

6

 

 

>$0.07

8

 

Floor heating

In use in the production areas (and parlor holding area)

10

 

Fuel rate, average

<$0.50/gal Propane

<$3.00/1000 CuFt Natural gas

1

 

 

$0.50-$0.75/gal Propane

$3.00-$4.00/CuFt Natural gas

2

 

 

$0.75-$1.00/gal Propane

$4.00-$5.00/CuFt Natural gas

4

 

 

>$1.00/gal Propane

>$5.00/CuFt Natural Gas

6

 

Use depreciation      

No

0

 

   On taxes

Partial

3

 

 

Entirely

8

 

Score

 

 

 

Interpretation:  0-20 = success questionable, 21-35= success possible,  35-46= greatest chance of success

RCM Digesters, Inc. - PO Box 4716 - Berkeley, CA 94704 
510.658.4466 - FAX: 510.658.2729 

Copyright  11/03/99 Resource Conservations Management, Inc. All rights reserved.