While no doubt biogas has considerable potential there are issues of scale, hygiene, animal welfare and water supply that may make it less applicable to Australia, or even 'sophisticated' China. I'd also point out that good fuel gas should not contain too much of the flame retardants CO2 and N2. Hallmarks of the middle class lifestyle in Australia are low water use, pampered animals and lack of smells. Apart from ponies we want livestock well away from the suburbs. Same goes for septic tanks and sewage farms. Currently those plants that can capture methane and sell incinerated sludge do so. I don't know to what extent distributing that system will increase yield. It's a bit like hydro dams on a river; more dams may not necessarily mean more power.

I think Aussies want clean dry power, not stinky subsurbs.

Great article. I "want" lots of things but I will settle for a few smells if it means something above basal survival.

Info on biogas from another permaculturist:

"I have thought for a long time that biodigestion is the only biomass -> energy scheme that is viable long term because:

1. The exotic processing component is naturally occurring bacteria already resident in basically any biomass stream (unlike ethanol).Human contribution is ANY airtight container (of course design alters practicality).

2. Feedstock flexible, no food vs fuel, CH4 per kg proportional to the energy content of input (turd < grass < fruit / seeds < offal < fats)

3. With a welder (powered by biogas gensets) and a rubber plant you could repair it almost indefinately, assuming you had some scrapped cars / building steel around.

4. You only need 30C heat (57C is also good if you have got it) unlike ethanol

5. The fuel self separates from the biomass media (unlike ethanol)

6. The fuel is non corrosive (unlike ethanol).

7. It is compatible with current power gen / transport infrastructure as well as future developments (fuel cells) just in case we make it a fair way.

8. You can also integrate a small trickle of power very easily such that you can deliver large pulses (ie welding is very difficult with a small solar facility without massively over speced batteries, 100kW engines are EVERYWHERE).

9. Storage capacity is significantly lower embodied energy, lasts significantly longer, significantly cheaper IIRC and significantly more upgradable than battery storage.

10. Process 'waste' is high grade soil remediator and concentrated liquid fertiliser facilitating positive feedback within your biosystem (only take out C & H, and minerals made bioavailable 'mined' via soil microbes / fungi remain bioavailable, hence via right fungi / legume combo you can rapidly increase nutrient availability within the system). You also make a better home for soil bacteria by adding back the soil remediator.

11. Significant pathogen reduction (human and animal waste processing, also has significant odor reduction)

12. Weed seed destruction (better than compost) "

I have a timber salvage business (no, not recycling), which means we have lots of waste wood in the form of both offcuts and sawdust, which are costly to dispose of. One of the means we are investigating for disposal is power generation using wood gas as the fuel. The process is neither stinky nor smoky and it can produce quite a lot of good, reliable baseload power. Our initial investigations show that a tonne of woodwaste will produce about 7MWh of power, which isn't chickenfeed!

Good on the Chinese, I say and I hope to be able to utilise some of their knowledge in improving our own operations.