The results from the SPP analysis are presented in Table 9 which indicates a payback on the investment including an allowance for life time O&M costs of 2.2 years. As a general guide and for this exercise an investment with a payback of less than 3 years is considered to be an attractive proposition for the Meat Processing Industry (pers. comm. Mike Spence June 2012). Given the analysis is based on proportional costs and returns relative to the quantity of biogas produced the SPP for both scenarios are the same. The financial proposition however will be significantly different over the lifetime of the investment for each scenario and requires a more detailed analysis.